@article{wang_zhao_wu_xie_2023, title={Influence of Qinghai-Xizang Plateau snow cover on interannual variability of Western North Pacific tropical cyclone tracks}, volume={41}, ISSN={["2523-3521"]}, DOI={10.1007/s00343-023-2358-4}, number={6}, journal={JOURNAL OF OCEANOLOGY AND LIMNOLOGY}, author={Wang, Zhaohua and Zhao, Dongliang and Wu, Kejian and Xie, Lian}, year={2023}, month={Nov}, pages={2060–2076} }
 @article{sun_xie_2022, title={A Climatological Study of Successive Tropical Cyclone Events in North Atlantic}, volume={13}, ISSN={["2073-4433"]}, url={https://doi.org/10.3390/atmos13111909}, DOI={10.3390/atmos13111909}, abstractNote={This study presents the climatological characteristics and key environmental features that are conducive to the development of successive tropical cyclone events (STCs) over the North Atlantic Ocean. Composite analyses were conducted to analyze the temporal, spatial, and mean characteristics of the environmental conditions associated with historical STC events during the study period of 1950–2020. The results show that the tropical cyclone (TC)-induced Rossby waves could explain a majority of Atlantic STCs when newly formed TCs develop to the east of the pre-existing TC during the study period. The remaining STCs which could not be explained by the Rossby wave dispersion theory were likely the result of favorable environmental conditions conducive to the occurrence of the successive development of TCs. The composite analysis of the environmental conditions at various time scales reveals that the low-frequency variability of the environmental conditions likely plays a significant role in modulating the STCs over the North Atlantic Ocean.}, number={11}, journal={ATMOSPHERE}, author={Sun, Xia and Xie, Lian}, year={2022}, month={Nov} }
 @article{sun_xie_2022, title={A Comparative Study on the Performances of Spectral Nudging and Scale-Selective Data Assimilation Techniques for Hurricane Track and Intensity Simulations}, volume={10}, ISSN={["2225-1154"]}, url={https://doi.org/10.3390/cli10110168}, DOI={10.3390/cli10110168}, abstractNote={It is a common practice to use a buffer zone to damp out spurious wave growth due to computational error along the lateral boundary of limited-area weather and climate models. Although it is an effective technique to maintain model stability, an unintended side effect of using such buffer zones is the distortion of the data passing through the buffer zone. Various techniques are introduced to enhance the communication between the limited-area model’s inner domain and the outer domain, which provides lateral boundary values for the inner domain. Among them, scale-selective data assimilation (SSDA) and the spectral nudging (SPNU) techniques share similar philosophy, i.e., directly injecting the large-scale components of the atmospheric circulation from the outer model domain into the interior grids of the inner model domain by-passing the lateral boundary and the buffer zone, but the two methods are taking different implementation approaches. SSDA utilizes a 3-dimensional variational data assimilation procedure to accomplish the data injection objective, whereas SPNU uses a nudging process. In the present study, the two approaches are evaluated comparatively for simulating hurricane track and intensity in a pair of cases: Jeanne (2004) and Irma (2017) using the Weather Research and Forecasting (WRF) model. The results indicate that both techniques are effective in improving tropical cyclone intensity and track simulations by reducing the errors of the large-scale circulation in the inner model domain. The SSDA runs produced better simulations of temperature and humidity fields which are not directly nudged. The SSDA runs also produced more accurate storm intensities in both cases and more realistic structure in Hurricane Jeanne’s case than those produced by the SPNU runs. It should be noted, however, that extending these case study results to more general situations requires additional studies covering a large number of additional cases.}, number={11}, journal={CLIMATE}, author={Sun, Xia and Xie, Lian}, year={2022}, month={Nov} }
 @article{gao_xu_wang_sun_xie_cao_2022, title={Combined Impacts of Climate Variability Modes on Seasonal Precipitation Extremes Over China}, ISSN={["1573-1650"]}, DOI={10.1007/s11269-022-03150-z}, journal={WATER RESOURCES MANAGEMENT}, author={Gao, Tao and Xu, Yifei and Wang, Huixia Judy and Sun, Qiaohong and Xie, Lian and Cao, Fuqiang}, year={2022}, month={Apr} }
 @article{yu_gao_xie_zhang_zhang_xu_cao_chen_2022, title={Tropical cyclone over the western Pacific triggers the record-breaking '21/7' extreme rainfall in Henan, central-eastern China}, volume={17}, ISSN={["1748-9326"]}, DOI={10.1088/1748-9326/aca2c4}, abstractNote={During 19–21 July 2021, Henan located in central-eastern China experienced torrential rainfall that caused devastating floods and claimed more than 300 casualties. It remains unclear whether and to what extent this extreme precipitation event is contributed by Typhoon In-Fa (TIF). Here we quantify the contribution of TIF to this record-breaking ‘21/7’ rainfall using an air–sea coupled model with ensemble simulations. The modeling results show that the northwestward moisture transport along the confluence front of TIF and the western Pacific subtropical high (WPSH) contribute mostly to the precipitation extremes across Henan. A sensitivity experiment that removes the TIF effect confirms TIF’s role in shaping extreme rainfall. Specifically, without TIF, WPSH shifts the moisture transport northeastward and causes a heavy rainband over the Korean Peninsula, with much less precipitation over Henan. The water vapor budget over Henan suggests that the TIF-induced moisture advection is nine times greater than the local moisture supply and is effectively converted into clouds therein to reinforce precipitation extremes. The contribution of TIF to the ‘21/7’ Henan torrential rainfall on average could be as large as 42% by comparing the differences between simulated results with and without TIF’s effects.}, number={12}, journal={ENVIRONMENTAL RESEARCH LETTERS}, author={Yu, Yang and Gao, Tao and Xie, Lian and Zhang, Rong-Hua and Zhang, Wei and Xu, Hongxiong and Cao, Fuqiang and Chen, Bin}, year={2022}, month={Dec} }
 @article{sun_xie_shah_shen_2021, title={A Machine Learning Based Ensemble Forecasting Optimization Algorithm for Preseason Prediction of Atlantic Hurricane Activity}, volume={12}, ISSN={["2073-4433"]}, url={https://doi.org/10.3390/atmos12040522}, DOI={10.3390/atmos12040522}, abstractNote={In this study, nine different statistical models are constructed using different combinations of predictors, including models with and without projected predictors. Multiple machine learning (ML) techniques are employed to optimize the ensemble predictions by selecting the top performing ensemble members and determining the weights for each ensemble member. The ML-Optimized Ensemble (ML-OE) forecasts are evaluated against the Simple-Averaging Ensemble (SAE) forecasts. The results show that for the response variables that are predicted with significant skill by individual ensemble members and SAE, such as Atlantic tropical cyclone counts, the performance of SAE is comparable to the best ML-OE results. However, for response variables that are poorly modeled by individual ensemble members, such as Atlantic and Gulf of Mexico major hurricane counts, ML-OE predictions often show higher skill score than individual model forecasts and the SAE predictions. However, neither SAE nor ML-OE was able to improve the forecasts of the response variables when all models show consistent bias. The results also show that increasing the number of ensemble members does not necessarily lead to better ensemble forecasts. The best ensemble forecasts are from the optimally combined subset of models.}, number={4}, journal={ATMOSPHERE}, publisher={MDPI AG}, author={Sun, Xia and Xie, Lian and Shah, Shahil Umeshkumar and Shen, Xipeng}, year={2021}, month={Apr} }
 @article{asthana_krim_sun_roheda_xie_2021, title={Atlantic Hurricane Activity Prediction: A Machine Learning Approach}, volume={12}, ISSN={["2073-4433"]}, url={https://doi.org/10.3390/atmos12040455}, DOI={10.3390/atmos12040455}, abstractNote={Long-term hurricane predictions have been of acute interest in order to protect the community from the loss of lives, and environmental damage. Such predictions help by providing an early warning guidance for any proper precaution and planning. In this paper, we present a machine learning model capable of making good preseason-prediction of Atlantic hurricane activity. The development of this model entails a judicious and non-linear fusion of various data modalities such as sea-level pressure (SLP), sea surface temperature (SST), and wind. A Convolutional Neural Network (CNN) was utilized as a feature extractor for each data modality. This is followed by a feature level fusion to achieve a proper inference. This highly non-linear model was further shown to have the potential to make skillful predictions up to 18 months in advance.}, number={4}, journal={ATMOSPHERE}, publisher={MDPI AG}, author={Asthana, Tanmay and Krim, Hamid and Sun, Xia and Roheda, Siddharth and Xie, Lian}, year={2021}, month={Apr} }
 @article{gao_guan_sun_xie_2020, title={Tropical Cyclone Wind Speed Retrieval from Dual-Polarization Sentinel-1 EW Mode Products}, volume={37}, ISSN={["1520-0426"]}, DOI={10.1175/JTECH-D-19-0148.1}, abstractNote={Recent studies indicate that the cross-polarization synthetic aperture radar (SAR) images have the ability of retrieving high wind speed on ocean surface without wind direction input. This study presents a new approach for tropical cyclone (TC) wind speed retrieval utilizing thermal-noise-removed Sentinel-1 dual-polarization (VV + VH) Extra-Wide Swath (EW) Mode products. Based on 20 images of 9 TCs observed in the 2016 and 2018 and SAR-collocated European Centre for Medium-Range Weather Forecasts (ECMWF) fifth-generation reanalysis (ERA5) data and the National Oceanic and Atmospheric Administration (NOAA) Hurricane Research Division’s (HRD) Real-time Hurricane Wind Analysis System (H*Wind) data, a subswath-based geophysical model function (GMF) Sentinel-1 EW Mode Wind Speed Retrieval Model after Noise Removal (S1EW.NR) is developed and validated statistically. TC wind speed is retrieved by using the proposed GMF and the C-band model 5.N (CMOD5.N). The results show that the wind speeds retrieved by the S1EW.NR model are in good agreement with wind references up to 31 m s−1. The correlation coefficient, bias, and standard deviation between the retrieval results and reference wind speeds are 0.74, −0.11, and 3.54 m s−1, respectively. Comparison of the wind speeds retrieved from both channels suggests that the cross-polarized signal is more suitable for high–wind speed retrieval, indicating the promising capability of cross-polarization SAR for TC monitoring.}, number={9}, journal={JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY}, author={Gao, Yuan and Guan, Changlong and Sun, Jian and Xie, Lian}, year={2020}, month={Sep}, pages={1713–1724} }
 @article{wang_gao_shi_xie_2019, title={A Numerical Study on the Impact of High-Frequency Winds on the Peru Upwelling System during 2014-2016}, volume={7}, ISSN={["2077-1312"]}, DOI={10.3390/jmse7050161}, abstractNote={The contribution of high-frequency wind to the Peruvian upwelling system during 2014–2016 was studied using the Regional Ocean Modeling System (ROMS), forced by four different temporal resolution (six-hourly, daily, weekly, and monthly) wind forcing. A major effect of the high-frequency wind is its warming of the water at all depths along the Peruvian coast. The mechanism for the temperature changes induced by high-frequency wind forcing was analyzed through heat budget analysis, which indicated a three-layer structure. Vertical advection plays a leading role in the warming of the mixed layer (0–25 m), and enhanced vertical mixing balances the warming effect. Analysis suggests that around the depths of 25–60 m, vertical mixing warms the water by bringing heat from the surface to deeper depths. In waters deeper than 60 m, the effect of vertical mixing is negligible. The differences among the oceanic responses in the sensitivity experiments suggest that wind forcing containing variabilities at higher than synoptic frequencies must be included in the atmospheric forcing in order to properly simulate the Peru upwelling system.}, number={5}, journal={JOURNAL OF MARINE SCIENCE AND ENGINEERING}, author={Wang, Linhui and Gao, Huiwang and Shi, Jie and Xie, Lian}, year={2019}, month={May} }
 @article{gao_guan_sun_xie_2019, title={A Wind Speed Retrieval Model for Sentinel-1A EW Mode Cross-Polarization Images}, volume={11}, ISSN={["2072-4292"]}, DOI={10.3390/rs11020153}, abstractNote={In contrast to co-polarization (VV or HH) synthetic aperture radar (SAR) images, cross-polarization (CP for VH or HV) SAR images can be used to retrieve sea surface wind speeds larger than 20 m/s without knowing the wind directions. In this paper, a new wind speed retrieval model is proposed for European Space Agency (ESA) Sentinel-1A (S-1A) Extra-Wide swath (EW) mode VH-polarized images. Nineteen S-1A images under tropical cyclone condition observed in the 2016 hurricane season and the matching data from the Soil Moisture Active Passive (SMAP) radiometer are collected and divided into two datasets. The relationships between normalized radar cross-section (NRCS), sea surface wind speed, wind direction and radar incidence angle are analyzed for each sub-band, and an empirical retrieval model is presented. To correct the large biases at the center and at the boundaries of each sub-band, a corrected model with an incidence angle factor is proposed. The new model is validated by comparing the wind speeds retrieved from S-1A images with the wind speeds measured by SMAP. The results suggest that the proposed model can be used to retrieve wind speeds up to 35 m/s for sub-bands 1 to 4 and 25 m/s for sub-band 5.}, number={2}, journal={REMOTE SENSING}, author={Gao, Yuan and Guan, Changlong and Sun, Jian and Xie, Lian}, year={2019}, month={Jan} }
 @article{lin_liu_luo_xie_2019, title={Double fronts in the Yellow Sea in summertime identified using sea surface temperature data of multi-scale ultra-high resolution analysis}, volume={175}, ISSN={["1873-6955"]}, DOI={10.1016/j.csr.2019.02.004}, abstractNote={Fronts are ubiquitous phenomena in oceans, and they play a significant role in marine hydrodynamics and ecology. During the stratified season of a shelf sea, the coastal front is usually considered as a single front, i.e., the tidal mixing front. However, using high resolution (~1 km) Multi-scale Ultra-high Resolution (MUR) analysis sea surface temperature (SST) data, this study observes persistent double fronts along the Yellow Sea coast in summertime. The double fronts comprise the well-known offshore tidal mixing front and a nearshore front, and the nearshore front has not been previously reported. The climatological (2002–2017) monthly mean result shows that the double fronts with two SST gradient peaks exceeding ~2 °C/100 km and opposite SST gradient directions basically remain unchanged from June to August, whereas the frontal spacing decreases in September. Analyses based on a two-layer concept model suggest that a topographic slope along with tidal mixing could induce the pattern of double fronts. The frontogenesis of nearshore thermal front could be associated with the different responses of the water column of different water depths to insolation. The offshore movement of the nearshore front in September could be related to the fast cooling of nearshore water and intensified offshore wind, and the topographic slope is important for determining the pattern of double fronts (loose or tight). This study shows a new pattern of coastal fronts in the stratified season, and indicates the significance of high resolution satellite data. The discovery of the double front pattern implies the influence of coastal fronts during the stratified season on marine ecology and environment in a shelf sea might be underestimated.}, journal={CONTINENTAL SHELF RESEARCH}, author={Lin, Lei and Liu, Dongyan and Luo, Chongxin and Xie, Lian}, year={2019}, month={Mar}, pages={76–86} }
 @article{wang_gao_xie_2019, title={Extreme precipitation events during 1960-2011 for the Northwest China: space-time changes and possible causes}, volume={137}, ISSN={["1434-4483"]}, DOI={10.1007/s00704-018-2645-8}, number={1-2}, journal={THEORETICAL AND APPLIED CLIMATOLOGY}, author={Wang, Huailiang and Gao, Tao and Xie, Lian}, year={2019}, month={Jul}, pages={977–995} }
 @article{wang_gao_xie_2019, title={Extreme precipitation events during 1960-2011 for the Northwest China: space-time changes and possible causes (vol 137, pg 977, 2019)}, volume={137}, ISSN={["1434-4483"]}, DOI={10.1007/s00704-018-2668-1}, abstractNote={The original version of this article unfortunately contained a mistake. The presentation of Figs. 8 and 9 were incorrect due to the insertion of black thick slashes.}, number={1-2}, journal={THEORETICAL AND APPLIED CLIMATOLOGY}, author={Wang, Huailiang and Gao, Tao and Xie, Lian}, year={2019}, month={Jul}, pages={997–999} }
 @article{cao_gao_dan_xie_gong_2019, title={Variability of Summer Precipitation Events Associated with Tropical Cyclones over Mid-Lower Reaches of Yangtze River Basin: Role of the El Nino-Southern Oscillation}, volume={10}, ISSN={["2073-4433"]}, DOI={10.3390/atmos10050256}, abstractNote={Based on tropical cyclone (TC) track data and gridded observational rainfall data of CN05.1 during the period of 1961 to 2014, we examine the contribution of TCs on three metrics of summertime rainfall regimes and identify the connection between TC-induced precipitation events and El Niño–Southern Oscillation (ENSO) in middle–lower reaches of Yangtze River Basin (MLYRB). At the regional scale, TCs are responsible for approximately 14.4%, 12.5%, and 6.9% of rainfall events for normal, 75th, and 95th percentile precipitation cases, respectively. There is no evidence of significant long-term trends of the three type events linked with TCs, while their interdecadal variability is remarkable. Fractionally, larger proportions of TC-induced events occur along southeast coastal regions of MLYRB for normal rainfall events, and they are recorded over southwest and central-east MLYRB for 95th percentile cases. Moreover, a larger contribution of 95th percentile precipitation events to summer total rainfall is found than that for 75th percentile cases, suggesting that TCs may exert stronger impacts on the upper tail of summertime precipitation distribution across MLYRB. The TC-induced normal rainfall events tend to occur more frequency over central-west MLYRB during negative phase of ENSO in summer. However, the higher likelihood of TC-induced rainfall for three defined metrics are found over the majority of areas over MLYRB during negative ENSO phase in spring. In preceding winter, La Niña episode plays a crucial role in controlling the frequency of both normal and 75th percentile precipitation events.}, number={5}, journal={ATMOSPHERE}, author={Cao, Fuqiang and Gao, Tao and Dan, Li and Xie, Lian and Gong, Xiang}, year={2019}, month={May} }
 @article{gao_guan_sun_xie_2018, title={A New Hurricane Wind Direction Retrieval Method for SAR Images without Hurricane Eye}, volume={35}, ISSN={["1520-0426"]}, DOI={10.1175/JTECH-D-18-0053.1}, abstractNote={This study presents a new approach for hurricane wind direction retrieval utilizing rainband streaks contained in synthetic aperture radar (SAR) images without hurricane eye information, based on the hurricane inflow angle. To calculate the wind direction field, a method for estimating the location of the hurricane center is given. In this paper, four Sentinel-1A (S-1A) images with a hurricane eye are used to clarify the center estimation method. Three S-1A SAR images without a hurricane eye are studied to evaluate the accuracy of the new method. The estimated locations of hurricane centers show good agreement with hurricane track data provided by the National Oceanic and Atmospheric Administration (NOAA)’s Atlantic Oceanographic and Meteorological Laboratory (AOML) Hurricane Research Division (HRD), HurricaneCity, and the National Institute of Informatics (NII). To validate the estimated wind directions, the NOAA HRD dropwindsonde observations for Tropical Storm Karl are collected and compared. The wind directions retrieved by our approach are more consistent with visual inspection than the fast Fourier transform (FFT) method in subimages. Moreover, the retrieved wind speeds utilizing C-band model 5.N (CMOD5.N) are compared with wind speed estimations observed by Stepped Frequency Microwave Radiometer (SFMR). The results suggest that the proposed method has good potential to retrieve hurricane wind direction from SAR images without a hurricane eye and external data.}, number={11}, journal={JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY}, author={Gao, Yuan and Guan, Changlong and Sun, Jian and Xie, Lian}, year={2018}, month={Nov}, pages={2229–2239} }
 @article{zhang_xie_liu_guan_2017, title={An Integrated Approach for Assessing Tropical Cyclone Track and Intensity Forecasts}, volume={32}, ISSN={["1520-0434"]}, DOI={10.1175/waf-d-16-0161.1}, abstractNote={AbstractTrack, intensity, and, in some cases, size are usually used as separate evaluation parameters to assess numerical model performance on tropical cyclone (TC) forecasts. Such an individual-parameter evaluation approach often encounters contradictory skill assessments for different parameters, for instance, small track error with large intensity error and vice versa. In this study, an intensity-weighted hurricane track density function (IW-HTDF) is designed as a new approach to the integrated evaluation of TC track, intensity, and size forecasts. The sensitivity of the TC track density to TC wind radius was investigated by calculating the IW-HTDF with density functions defined by 1) asymmetric, 2) symmetric, and 3) constant wind radii. Using the best-track data as the benchmark, IW-HTDF provides a specific score value for a TC forecast validated for a specific date and time or duration. This new TC forecast evaluation approach provides a relatively concise, integrated skill score compared with multip...}, number={3}, journal={WEATHER AND FORECASTING}, author={Zhang, Wenqing and Xie, Lian and Liu, Bin and Guan, Changlong}, year={2017}, month={Jun}, pages={969–990} }
 @article{gao_xie_liu_2016, title={Association of extreme precipitation over the Yangtze River Basin with global air-sea heat fluxes and moisture transport}, volume={36}, ISSN={["1097-0088"]}, DOI={10.1002/joc.4534}, abstractNote={Although the effect of sea surface temperature anomalies in the Pacific and Indian Oceans on precipitation over the Yangtze River Basin (YRB) is well known, the impact of air–sea sensible and latent heat fluxes (SHF and LHF) has not been well studied. Based on the statistical and diagnostic analyses of historical precipitation data over the YRB, SHF and LHF over the global ocean, as well as global atmospheric reanalysis data, the impacts of SHF and LHF in the selected ocean regions on YRB extreme precipitation were investigated. The spatial distributions of the correlation coefficients between the YRB extreme precipitation indices (YRB‐EPI) and SHF and LHF over the global ocean were analysed to identify critical air–sea interaction regions affecting YRB extreme precipitation. Results show that a significant positive correlation exists between YRB‐EPI and air–sea heat fluxes over the Northwest Indian Ocean, Southeast Indian Ocean, Southwest Indian Ocean and South China Sea regions. Negative correlations were found over Central Equatorial Pacific, while positive lagged correlations exist over East Pacific. Composite analyses of global wind, geo‐potential height and water vapour transport were also conducted for ten heaviest and ten lightest YRB precipitation years, respectively. In heavy YRB precipitation years, the atmospheric circulation pattern is generally characterized by a strengthened Western Pacific Subtropical High (WPSH) extending northwestward, a strengthened lower tropospheric convergence zone over the YRB, three distinct moisture transport paths from adjacent oceans to the YRB and low‐level mid‐latitude northerly wind anomalies. Whereas, in light YRB precipitation years, it is dominated by the southwesterly summer monsoon over the YRB, with a convergence zone displaced to the north of the YRB, a weak WPSH, and only two main paths of moisture transport. These distinctions between the heavy and light YRB precipitation years provide a physical basis for establishing a statistical prediction model for YRB extreme precipitation.}, number={8}, journal={INTERNATIONAL JOURNAL OF CLIMATOLOGY}, author={Gao, Tao and Xie, Lian and Liu, Bin}, year={2016}, month={Jun}, pages={3020–3038} }
 @article{liu_lin_xie_gao_2016, title={Partially implicit finite difference scheme for calculating dynamic pressure in a terrain-following coordinate non-hydrostatic ocean model}, volume={106}, ISSN={["1463-5011"]}, DOI={10.1016/j.ocemod.2016.09.004}, abstractNote={To improve the efficiency of the terrain-following σ-coordinate non-hydrostatic ocean model, a partially implicit finite difference (PIFD) scheme is proposed. By using explicit terms instead of implicit terms to discretize the parts of the vertical dynamic pressure gradient derived from the σ-coordinate transformation, the coefficient matrix of the discrete Poisson equation that the dynamic pressure satisfies can be simplified from 15 diagonals to 7 diagonals. The PIFD scheme is shown to run stably when it is applied to simulate five benchmark cases, namely, a standing wave in a basin, a surface solitary wave, a lock-exchange problem, a periodic wave over a bar and a tidally induced internal wave. Compared with the conventional fully implicit finite difference (FIFD) scheme, the PIFD scheme produces simulation results of equivalent accuracy at only 40–60% of the computational cost. The PIFD scheme demonstrates strong applicability and can be easily implemented in σ-coordinate ocean models.}, journal={OCEAN MODELLING}, author={Liu, Zhe and Lin, Lei and Xie, Lian and Gao, Huiwang}, year={2016}, month={Oct}, pages={44–57} }
 @article{gao_xie_2016, title={Spatiotemporal changes in precipitation extremes over Yangtze River basin, China, considering the rainfall shift in the late 1970s}, volume={147}, ISSN={["1872-6364"]}, DOI={10.1016/j.gloplacha.2016.10.016}, abstractNote={Precipitation extremes are the dominated causes for the formation of severe flood disasters at regional and local scales under the background of global climate change. In the present study, five annual extreme precipitation events, including 1, 7 and 30 day annual maximum rainfall and 95th and 97.5th percentile threshold levels, are analyzed relating to the reference period 1960–2011 from 140 meteorological stations over Yangtze River basin (YRB). A generalized extreme value (GEV) distribution is applied to fit annual and percentile extreme precipitation events at each station with return periods up to 200 years. The entire time period is divided into preclimatic (preceding climatic) period 1960–1980 and aftclimatic (after climatic) period 1981–2011 by considering distinctly abrupt shift of precipitation regime in the late 1970s across YRB. And the Mann-Kendall trend test is adopted to conduct trend analysis during pre- and aftclimatic periods, respectively, for the purpose of exploring possible increasing/decreasing patterns in precipitation extremes. The results indicate that the increasing trends for return values during aftclimatic period change significantly in time and space in terms of different magnitudes of extreme precipitation, while the stations with significantly positive trends are mainly distributed in the vicinity of the mainstream and major tributaries as well as large lakes, this would result in more tremendous flood disasters in the mid-lower reaches of YRB, especially in southeast coastal regions. The increasing/decreasing linear trends based on annual maximum precipitation are also investigated in pre- and aftclimatic periods, respectively, whereas those changes are not significantly similar to the variations of return values during both subperiods. Moreover, spatiotemporal patterns of precipitation extremes become more uneven and unstable in the second half period over YRB.}, journal={GLOBAL AND PLANETARY CHANGE}, author={Gao, Tao and Xie, Lian}, year={2016}, month={Dec}, pages={106–124} }
 @article{bin_changlong_lian_dongliang_2015, title={Derivation of a wave-state-dependent sea spray generation function and its application in estimating sea spray heat flux}, volume={58}, ISSN={["1869-1897"]}, DOI={10.1007/s11430-015-5169-4}, number={10}, journal={SCIENCE CHINA-EARTH SCIENCES}, author={Bin, Liu and ChangLong, Guan and Lian, Xie and DongLiang, Zhao}, year={2015}, month={Oct}, pages={1862–1871} }
 @article{lin_liu_xie_gao_cai_chen_zhao_2015, title={Dynamics governing the response of tidal current along the mouth of Jiaozhou Bay to land reclamation}, volume={120}, ISSN={["2169-9291"]}, DOI={10.1002/2014jc010434}, abstractNote={7 Abstract Data collected from the previous studies show that the tidal current along the mouth of Jiaoz- 8 hou Bay (JZB) appears to have weakened, whereas the spatial asymmetry (stronger flooding in the north 9 region and stronger ebbing in the south region) has remained nearly unchanged during the past AQ4 several 10 decades of large-scale land reclamation. This study is conducted to explain the underlying dynamics for this 11 phenomenon. The analytic evaluation of the tidal motion indicates that the tidal current in a small coastal 12 bay such as the JZB is linearly proportional to its length (L), if L is far less than one-quarter of the tidal wave 13 length. This relation suggests that the decrease in tidal current speed in JZB mouth results from the land 14 reclamation within the Bay. Also, the relationship between bay areas and tidal current along the JZB mouth 15 can be derived. The results of this simple theoretical method for predicting the change in mean tidal current 16 amplitude after the land reclamation largely agree with previous three-dimensional (3-D) modeling studies. 17 It is also found that the spatial asymmetry of the tidal current along the JZB mouth is controlled by the 18 sharp headland (the local factor). The unchanged shoreline around the headland leads to the stable spatial 19 asymmetry of the tidal current. The weaker tidal current can explain the weaker residual current, and the 20 unchanged asymmetry of the tidal current explains the unaltered pattern of inflow over the north region}, number={4}, journal={JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS}, author={Lin, Lei and Liu, Zhe and Xie, Lian and Gao, Huiwang and Cai, Zhongya and Chen, Ziyu and Zhao, Jianzhong}, year={2015}, month={Apr}, pages={2958–2972} }
 @article{sun_xie_semazzi_liu_2015, title={Effect of Lake Surface Temperature on the Spatial Distribution and Intensity of the Precipitation over the Lake Victoria Basin}, volume={143}, ISSN={["1520-0493"]}, DOI={10.1175/mwr-d-14-00049.1}, abstractNote={AbstractA series of sensitivity experiments are performed to investigate the response of precipitation over the Lake Victoria basin (LVB) to the changes of lake surface temperature (LST) using the Weather Research and Forecasting (WRF) Model. It is shown that the default LST initialized from NCEP FNL (Final) Operational Global Analysis is deficient for simulating the rainfall over the LVB. Comparative experiments demonstrate the unambiguous impact of LST on the intensity and pattern of the precipitation over LVB. Intensification/weakening of precipitation over the lake occur with increasing/decreasing LST for both uniform and asymmetrical LST distribution. However, the relationship between rainfall anomalies and LST variations is nonlinear. Replacing the LST directly derived from global weather forecast models by the mean area-averaged LST of Lake Victoria (approximately 24°C) leads to improved rainfall simulation. However, LST with realistic cross-basin gradient is necessary to obtain a rainfall pattern ...}, number={4}, journal={MONTHLY WEATHER REVIEW}, author={Sun, Xia and Xie, Lian and Semazzi, Fredrick and Liu, Bin}, year={2015}, month={Apr}, pages={1179–1192} }
 @article{xie_semazzi_hanna_anyah_gao_he_2015, title={Regional Climate Change: Downscaling, Prediction, and Impact Assessment}, volume={2015}, ISSN={["1687-9317"]}, DOI={10.1155/2015/290281}, abstractNote={Although the issue of climate change is often dealt with in global perspective, the impact of climate change must be assessed at regional scales. While global climate models can provide projections of the average state of large-scale circulation of future climate, the downscaling of such projections to regional scale with improved spatial and temporal resolution for both the forcing fields and the climatic responses is the basis for assessing the societal impacts of climate change. Therefore, it is important to not only study climate change at the global scale but also study the regional manifestations of the climate system at spatial scales ranging from less than a hundred kilometers to thousands of kilometers with time scales from months to years to decades. This special issue publishes a collection of articles covering a wide range of topics of our understanding of “regional climate” from downscaling the variability of extreme rainfall over the Yangtze River basin (T. Gao and L. Xie) and assessing the water resources in the Yellow River region (Z. Wu et al.) in China to forecasting the precipitation and water resources in the Lake Victoria region in East Africa (X. Sun et al., R. Argent et al., and K. A. Smith and F. H. M. Semazzi), from downscaling wind energy resources in the contiguous United States (B. Liu et al.) to characterizing the precipitation extremes in the Carpathian region in central and southern Europe (L. Gaal et al.), and from analyzing the energy balance in semiarid grasslands in China (Q. Jiang et al.) to detecting future climate change signals in central and eastern Europe from numerical model simulations (M. Belda et al.). This special issue also includes articles addressing the impacts of regional climate change on tropical cyclones over the Atlantic Ocean (K. Xie and B. Liu), on crop yields in North China (H. Liu et al.), and on litter production and nutrient dynamics in a plantation in China (X. Ge et al.), as well as rainfall and drought in Eastern Kenya (M. O. Kisaka et al.). Additionally, several articles with focus on regional climate downscaling methodologies are also included. S. Kim et al. studied the effects of geographic features in a mountainous area on the downscaling of global climate model data; T. R. Lee et al. demonstrated the feasibility of using PRISM (parameterelevation regression on independent slope model) to downscale maximum temperature to subkilometer scale; L. Gao et al. applied the LASSO algorithm to statistically downscale the ERA-interim precipitation forecast over complex terrain; and K.-H. Min and W.-Y. Sun explored the application of an atmosphere-cryosphere coupledmodel in regional climate applications. These articles reflect the recent advances and applications in “regional climate downscaling, prediction, and impact assessment” from a set of unique angles. We hope they are of interest to peers.}, journal={ADVANCES IN METEOROLOGY}, author={Xie, Lian and Semazzi, Fredrick and Hanna, Adel and Anyah, Richard and Gao, Huiwang and He, Yijun}, year={2015} }
 @article{sun_xie_semazzi_liu_2014, title={A Numerical Investigation of the Precipitation over Lake Victoria Basin Using a Coupled Atmosphere-Lake Limited-Area Model}, volume={2014}, ISSN={["1687-9317"]}, DOI={10.1155/2014/960924}, abstractNote={By using a coupled atmosphere-lake model, which consists of the Weather Research and Forecasting (WRF) model and the Princeton Ocean Model (POM), the present study generated realistic lake surface temperature (LST) over Lake Victoria and revealed the prime importance of LST on the precipitation pattern over the Lake Victoria Basin (LVB). A suite of sensitivity experiments was conducted for the selection of an optimal combination of physics options including cumulus, microphysics, and planetary boundary layer schemes for simulating precipitation over the LVB. The WRF-POM coupled system made a great performance on simulating the expected LST, which is featured with eastward temperature gradient as in the real bathymetry of the lake. Under thorough examination of diagnostic analysis, a distinguished diurnal phenomenon has been unveiled. The precipitation mainly occurs during the nocturnal peak between midnight and early in the morning, which is associated with the strong land breeze circulation, when the lake temperature is warmer than the adjacent land. Further exploration of vertical velocity, surface divergence pattern, and maximum radar reflectivity confirms such conjecture. The time-longitude analysis of maximum radar reflectivity over the entire lake also shows a noticeable pattern of dominating westward propagation.}, journal={ADVANCES IN METEOROLOGY}, publisher={Hindawi Publishing Corporation}, author={Sun, Xia and Xie, Lian and Semazzi, Fredrick H. M. and Liu, Bin}, year={2014} }
 @article{liu_costa_xie_semazzi_2014, title={Dynamical downscaling of climate change impacts on wind energy resources in the contiguous United States by using a limited-area model with scale-selective data assimilation}, DOI={10.1155/2014/897246}, abstractNote={By using a limited-area model (LAM) in combination with the scale-selective data assimilation (SSDA) approach, wind energy resources in the contiguous United States (CONUS) were downscaled from IPCC CCSM3 global model projections for both current and future climate conditions. An assessment of climate change impacts on wind energy resources in the CONUS region was then conducted. Based on the downscaling results, when projecting into future climate under IPCC’s A1B scenario, the average annual wind speed experiences an overall shift across the CONUS region. From the current climate to the 2040s, the average annual wind speed is expected to increase from 0.1 to 0.2 m s−1 over the Great Plains, Northern Great Lakes Region, and Southwestern United States located southwest of the Rocky Mountains. When projecting into the 2090s from current climate, there is an overall increase in the Great Plains Region and Southwestern United States located southwest of the Rockies with a mean wind speed increase between 0 and 0.1 m s−1, while, the Northern Great Lakes Region experiences an even greater increase from current climate to 2090s than over the first few decades with an increase of mean wind speed from 0.1 to 0.4 m s−1.}, journal={Advances in Meteorology}, author={Liu, B. and Costa, K. B. and Xie, L. and Semazzi, F. H. M.}, year={2014} }
 @article{gao_xie_2014, title={Multivariate Regression Analysis and Statistical Modeling for Summer Extreme Precipitation over the Yangtze River Basin, China}, volume={2014}, ISSN={["1687-9317"]}, DOI={10.1155/2014/269059}, abstractNote={Extreme precipitation is likely to be one of the most severe meteorological disasters in China; however, studies on the physical factors affecting precipitation extremes and corresponding prediction models are not accurately available. From a new point of view, the sensible heat flux (SHF) and latent heat flux (LHF), which have significant impacts on summer extreme rainfall in Yangtze River basin (YRB), have been quantified and then selections of the impact factors are conducted. Firstly, a regional extreme precipitation index was applied to determine Regions of Significant Correlation (RSC) by analyzing spatial distribution of correlation coefficients between this index and SHF, LHF, and sea surface temperature (SST) on global ocean scale; then the time series of SHF, LHF, and SST in RSCs during 1967–2010 were selected. Furthermore, other factors that significantly affect variations in precipitation extremes over YRB were also selected. The methods of multiple stepwise regression and leave-one-out cross-validation (LOOCV) were utilized to analyze and test influencing factors and statistical prediction model. The correlation coefficient between observed regional extreme index and model simulation result is 0.85, with significant level at 99%. This suggested that the forecast skill was acceptable although many aspects of the prediction model should be improved.}, journal={ADVANCES IN METEOROLOGY}, author={Gao, Tao and Xie, Lian}, year={2014} }
 @article{deng_gao_gao_yao_xie_2014, title={Regional precipitation variability in East Asia related to climate and environmental factors during 1979-2012}, volume={4}, ISSN={["2045-2322"]}, DOI={10.1038/srep05693}, abstractNote={This paper studies the inter-annual precipitation variations in different regions of East Asia from oceans to interior areas in China during 1979 - 2012. The results computed by Empirical Orthogonal Functions (EOF) demonstrate that the annual precipitation changes are mainly related to the El Niño-Southern Oscillation, East Asian summer monsoon and aerosols. We also found that the increased Sea surface temperature (SST) could explain the precipitation changes over the Northwest Pacific in the dry season (Oct. - May) and the East China Sea and the South China Sea in the rainy season (Jun. - Sep.). The precipitation changes over the ocean unexplained by SST were likely due to the water vapor transport dominated by dynamic factors. With the increased SST, the moisture transported from oceans to interior land was likely redistributed and caused the complicated regional variability of precipitation. Moreover, the impacts of aerosols on cloud and precipitation varied with different pollution levels and different seasons.}, journal={SCIENTIFIC REPORTS}, author={Deng, Yinyin and Gao, Tao and Gao, Huiwang and Yao, Xiaohong and Xie, Lian}, year={2014}, month={Jul} }
 @article{peng_li_xie_2013, title={Adjusting the Wind Stress Drag Coefficient in Storm Surge Forecasting Using an Adjoint Technique}, volume={30}, ISSN={["1520-0426"]}, DOI={10.1175/jtech-d-12-00034.1}, abstractNote={A three-dimensional ocean model and its adjoint model are used to adjust the drag coefficient in the calculation of wind stress for storm surge forecasting. A number of identical twin experiments (ITEs) with different error sources imposed are designed and performed. The results indicate that when the errors come from the wind speed, the drag coefficient is adjusted to an "optimal value" to compensate for the wind errors, resulting in significant improvements of the specific storm surge forecasting. In practice, the "true" drag coefficient is unknown and the wind field, which is usually calculated by an empirical parameter model or a numerical weather prediction model, may contain large errors. In addition, forecasting errors may also come from imperfect model physics and numerics, such as insufficient resolution and inaccurate physical parameterizations. The results demonstrate that storm surge forecasting errors can be reduced through data assimilation by adjusting the drag coefficient regardless of the error sources. Therefore, although data assimilation may not fix model imperfection, it is effective in improving storm surge forecasting by adjusting the wind stress drag coefficient using the adjoint technique.}, number={3}, journal={JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY}, author={Peng, Shiqiu and Li, Yineng and Xie, Lian}, year={2013}, month={Mar}, pages={590–608} }
 @article{xie_liu_morrison_gao_wang_2013, title={Air-Sea Interactions and Marine Meteorology}, volume={2013}, ISSN={["1687-9317"]}, DOI={10.1155/2013/162475}, journal={ADVANCES IN METEOROLOGY}, author={Xie, Lian and Liu, Bin and Morrison, John and Gao, Huiwang and Wang, Jianhong}, year={2013} }
 @article{liu_xie_morrison_kamykowski_2013, title={Dynamic Downscaling of the Impact of Climate Change on the Ocean Circulation in the Galapagos Archipelago}, volume={2013}, ISSN={["1687-9317"]}, DOI={10.1155/2013/837432}, abstractNote={The regional impact of global climate change on the ocean circulation around the Galapagos Archipelago is studied using the Hybrid Coordinate Ocean Model (HYCOM) configured for a four-level nested domain system. The modeling system is validated and calibrated using daily atmospheric forcing derived from the NCEP/NCAR reanalysis dataset from 1951 to 2007. The potential impact of future anthropogenic global warming (AGW) in the Galapagos region is examined using the calibrated HYCOM with forcing derived from the IPCC-AR4 climate model. Results show that although the oceanic variability in the entire Galapagos region is significantly affected by global climate change, the degree of such effects is inhomogeneous across the region. The upwelling region to the west of the Isabella Island shows relatively slower warming trends compared to the eastern Galapagos region. Diagnostic analysis suggests that the variability in the western Galapagos upwelling region is affected mainly by equatorial undercurrent (EUC) and Panama currents, while the central/east Galapagos is predominantly affected by both Peru and EUC currents. The inhomogeneous responses in different regions of the Galapagos Archipelago to future AGW can be explained by the incoherent changes of the various current systems in the Galapagos region as a result of global climate change.}, journal={ADVANCES IN METEOROLOGY}, author={Liu, Yanyun and Xie, Lian and Morrison, John M. and Kamykowski, Daniel}, year={2013} }
 @article{tang_xie_lackmann_liu_2013, title={Modeling the Impacts of the Large-Scale Atmospheric Environment on Inland Flooding during the Landfall of Hurricane Floyd (1999)}, volume={2013}, ISSN={["1687-9317"]}, DOI={10.1155/2013/294956}, abstractNote={The contribution of the large-scale atmospheric environment to precipitation and flooding during Hurricane Floyd was investigated in this study. Through the vortex removal technique in the Weather Research and Forecasting (WRF) model, the vortex associated with Hurricane Floyd (1999) was mostly removed in the model initial conditions and subsequent integration. Results show that the environment-induced precipitation can account for as much as 22% of total precipitation in the innermost model domain covering North Carolina coastal area and 7% in the focused hydrological study area. The high-resolution precipitation data from the WRF model was then used for input in a hydrological model to simulate river runoff. Hydrological simulation results demonstrate that without the tropical systems and their interactions with the large-scale synoptic environment the synoptic environment would only contribute 10% to the total discharge at the Tarboro gauge station. This suggests that Hurricane Floyd and Hurricane Dennis preceding it, along with the interactions between these tropical systems and the large-scale environment, have contributed to the bulk (90%) of the record amount of flood water in the Tar-Pamlico River Basin.}, journal={ADVANCES IN METEOROLOGY}, author={Tang, Qianhong and Xie, Lian and Lackmann, Gary M. and Liu, Bin}, year={2013} }
 @article{deng_xie_yu_shi_jin_wu_2013, title={Numerical Study of the Effects of Wave-Induced Forcing on Dynamics in Ocean Mixed Layer}, volume={2013}, ISSN={["1687-9317"]}, DOI={10.1155/2013/365818}, abstractNote={Numerical experiments using hybrid coordinate ocean model (HYCOM) are designed to quantify the effects of wind wave-induced Coriolis-Stokes forcing (CSF) on mixed layer (ML) dynamics in a global context. CSF calculated by the wave parameters simulated by using the WaveWatch III (WW3) model is introduced as a new driving force for HYCOM. The results show that noticeable influence on ocean circulation in ML can be caused by CSF. Over most of the global oceans the direction of Stokes transport is different from that of the change in current transport caused by CSF. This is not unusual because CSF is normal to Stokes drift. However, the CSF-caused change in current transport and the wave-induced Stokes transport have the same magnitude. The seasonal variabilities of mixed layer temperature (MLT) and mixed layer depth (MLD) caused by CSF are analyzed, and the possible relationship between them is also given.}, journal={ADVANCES IN METEOROLOGY}, author={Deng, Zengan and Xie, Lian and Yu, Ting and Shi, Suixiang and Jin, Jiye and Wu, Kejian}, year={2013} }
 @article{liu_zhang_li_xie_2013, title={Numerical study of the sensitivity of mangroves in reducing storm surge and flooding to hurricane characteristics in southern Florida}, volume={64}, ISSN={["0278-4343"]}, DOI={10.1016/j.csr.2013.05.015}, abstractNote={The sensitivity of the mangrove effect on reducing storm surge flooding to hurricane characteristics is investigated by using the numerical model Coastal and Estuarine Storm Tide (CEST). First, the attenuation of storm surge by mangroves is incorporated into the model by updating Manning’s coefficient based on the National Land Cover Dataset (NLCD) 2001. Then CEST is verified by comparing the model results with field observations in South Florida for Hurricane Wilma. Secondly, a set of numerical experiments using synthetic hurricanes with different intensity, forward speed, radius of maximum wind speed and travel direction are conducted for the sensitivity study. Results indicate that storm surge magnitudes and flooding areas are reduced by the mangrove zone more for fast moving hurricanes than slow moving hurricanes in the west coast of South Florida. In addition, increasing hurricane intensity and hurricane size lower the effect of mangroves on attenuating storm surge and reducing the flooding area. The mangrove zone plays a more effective role in reducing flooding areas from hurricanes that travel from east to west than from hurricanes that travel from west to east. The mangrove reduction effect is most sensitive to changes in hurricane forward speed. A 6.7 m/s to 2.2 m/s decrease in forward speed can result in a decrease in flood area reduction by mangroves that is equivalent to the decrease in flood area reduction by mangroves from Category 3 to 5 hurricanes.}, journal={CONTINENTAL SHELF RESEARCH}, author={Liu, Huiqing and Zhang, Keqi and Li, Yuepeng and Xie, Lian}, year={2013}, month={Aug}, pages={51–65} }
 @article{li_peng_yan_xie_2013, title={On improving storm surge forecasting using an adjoint optimal technique}, volume={72}, ISSN={["1463-5011"]}, DOI={10.1016/j.ocemod.2013.08.009}, abstractNote={A three-dimensional ocean model and its adjoint model are used to simultaneously optimize the initial conditions (IC) and the wind stress drag coefficient (Cd) for improving storm surge forecasting. To demonstrate the effect of this proposed method, a number of identical twin experiments (ITEs) with a prescription of different error sources and two real data assimilation experiments are performed. Results from both the idealized and real data assimilation experiments show that adjusting IC and Cd simultaneously can achieve much more improvements in storm surge forecasting than adjusting IC or Cd only. A diagnosis on the dynamical balance indicates that adjusting IC only may introduce unrealistic oscillations out of the assimilation window, which can be suppressed by the adjustment of the wind stress when simultaneously adjusting IC and Cd. Therefore, it is recommended to simultaneously adjust IC and Cd to improve storm surge forecasting using an adjoint technique.}, journal={OCEAN MODELLING}, author={Li, Yineng and Peng, Shiqiu and Yan, Jing and Xie, Lian}, year={2013}, month={Dec}, pages={185–197} }
 @article{li_xie_liu_guan_2013, title={On the sensitivity of hurricane storm surge simulation to domain size}, volume={67}, ISSN={["1463-5011"]}, DOI={10.1016/j.ocemod.2013.03.005}, abstractNote={The impact of model domain size on the simulated storm surge under various hurricane and topographic conditions is investigated by using a three-dimensional storm surge model. Idealized experiments are designed to simulate storm surge with different domain sizes under various hurricane intensities, radius of maximum wind (RMW), translation speeds and landfall directions, coastal ocean bottom slopes, and continental shelf extents. The results show that, in general, the simulated storm surge first increases with increasing domain size and then approaches a constant value. A “threshold domain size” is defined accordingly, so that differences among model results with different domain sizes larger than the threshold domain size are negligible. The threshold domain size is shown to be insensitive to hurricane intensities, but increases linearly with increasing hurricane RMWs. It also increases with increasing translation speeds and decreasing bottom slopes, when hurricanes approach land perpendicularly. The threshold domain size can also be affected by other factors such as the direction of the storm track of a landfalling hurricane and the extent of continental shelf. Considering the complex dependence of the threshold domain size on various hurricane parameters, a polar graphic chart is created for estimating the threshold domain size for possible hurricane landfall directions and RMWs. A real case study of hurricane Charley (2004) is conducted with different domain sizes. Model results indicate that the threshold domain size estimated from the idealized experiments is reasonable for practical applications.}, journal={OCEAN MODELLING}, author={Li, Rui and Xie, Lian and Liu, Bin and Guan, Changlong}, year={2013}, month={Jul}, pages={1–12} }
 @article{dongliang_xin_bin_lian_2013, title={Rainfall effect on wind waves and the turbulence beneath air-sea interface}, volume={32}, ISSN={["1869-1099"]}, DOI={10.1007/s13131-013-0372-7}, number={11}, journal={ACTA OCEANOLOGICA SINICA}, author={Dongliang, Zhao and Xin, Ma and Bin, Liu and Lian, Xie}, year={2013}, month={Nov}, pages={10–20} }
 @inproceedings{sheng_davis_figueiredo_liu_liu_luettich_paramygin_weaver_weisberg_xie_et al._2012, title={A Regional Testbed for Storm Surge and Coastal Inundation Models—An Overview}, ISBN={9780784412411}, url={http://dx.doi.org/10.1061/9780784412411.00028}, DOI={10.1061/9780784412411.00028}, abstractNote={Since 2008, a Regional Testbed has been comparing storm surge models in terms of historical storm simulations and coastal inundation maps, e.g., Flood Insurance Rate Maps and Surge Atlas. The models include two structured grid (CH3D and POM) and two unstructured grid (ADCIRC and FVCOM) models. During 2008, the storm surge and coastal inundation in the Chesapeake Bay and the Outer Banks of North Carolina during Hurricane Isabel was simulated and the results compared in an independent but non-interoperable effort by partners. In 2009-2010, an additional model SLOSH was added, and all five models were used to simulate the storm surge and coastal inundation in southwest Florida during Hurricane Charley and the results compared. Model inputs and outputs were designed in an interoperable fashion, using common model input data, parameterization and coefficients, common model output formats using a common model data grid. Thirty scenarios were developed to test the sensitivity of the models to bathymetry, storm forcing, wind drag coefficient, bottom friction, Coriolis, 2D vs. 3D formulation, etc. Various types of model products, including time series of storm surge and maximum inundation over the entire model domain, were compared to each other and measured data. The detailed model simulations and comparisons required considerable computational and analysis time, but resulted in the discovery of how model features affected the model accuracy, leading to an overall improvement of all the models used. Testbed results showed differences in storm surge elevation and coastal inundation during both Isabel and Charley. While the simulated water level at the observed stations generally did not differ by more than 20% and no model appears to be consistently superior / inferior to any other model, there are more significant differences in the produced inundation maps. The computational efficiency differs considerably among the various models. Additional simulations of a large number (20+) of storms and domains are needed to better define the relative importance of different model parameters and to sort out the causes for subtle differences among the model results. More in-depth model inter comparison results will be forthcoming in a future paper.}, booktitle={Estuarine and Coastal Modeling}, publisher={American Society of Civil Engineers}, author={Sheng, Y. Peter and Davis, Justin R. and Figueiredo, Renato and Liu, Bin and Liu, Huiqing and Luettich, Rick and Paramygin, Vladimir A. and Weaver, Robert and Weisberg, Robert and Xie, Lian and et al.}, year={2012}, month={Nov} }
 @article{bin_changlong_xie_dongliang_2012, title={An Investigation of the Effects of Wave State and Sea Spray on an Idealized Typhoon Using an Air Sea Coupled Modeling System}, volume={29}, ISSN={["1861-9533"]}, DOI={10.1007/s00376-011-1059-7}, number={2}, journal={ADVANCES IN ATMOSPHERIC SCIENCES}, author={Bin, Liu and Changlong, Guan and Xie, Li'an and Dongliang, Zhao}, year={2012}, month={Mar}, pages={391–406} }
 @article{zeng'an_li'an_guijun_xuefeng_kejian_2012, title={The effect of Coriolis-Stokes forcing on upper ocean circulation in a two-way coupled wave-current model}, volume={30}, ISSN={["1993-5005"]}, DOI={10.1007/s00343-012-1069-z}, number={2}, journal={CHINESE JOURNAL OF OCEANOLOGY AND LIMNOLOGY}, author={Zeng'an, Deng and Li'an, Xie and Guijun, Han and Xuefeng, Zhang and Kejian, Wu}, year={2012}, month={Mar}, pages={321–335} }
 @article{liu_guan_xie_2012, title={The wave state and sea spray related parameterization of wind stress applicable from low to extreme winds}, volume={117}, ISSN={["2169-9291"]}, DOI={10.1029/2011jc007786}, abstractNote={Received 28 November 2011; revised 21 May 2012; accepted 23 May 2012; published 3 July 2012. [1] Recent field and laboratory observations indicate that the variation of drag coefficient with wind speed at high winds is different from that under low-to-moderate winds. By taking the effects of wave development and sea spray into account, a parameterization of sea surface aerodynamic roughness applicable from low to extreme winds is proposed. The corresponding relationship between drag coefficient and sea surface wind speed agrees well with the existing field and laboratory observational data. It is shown that, under low-to-moderate wind conditions so that the sea spray effects could be neglected, the nondimensional aerodynamic roughness first increases and then decreases with the increasing wave age; whereas under high wind conditions, the drag coefficient decreases with the increasing wind speed due to the modification of the logarithmic wind profile by the effect of sea spray droplets produced by bursting bubbles or wind tearing breaking wave crests. The drag coefficients and sea surface aerodynamic roughnesses reach their maximum values when the 10 m wind speeds are between 25 and 33 m s � 1 for different wave developments. Correspondingly, the reduction of drag coefficient under high winds reduces the increasing rate of friction velocity with increasing wind speed.}, journal={JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS}, author={Liu, Bin and Guan, Changlong and Xie, Lian}, year={2012}, month={Jul} }
 @article{liu_liu_xie_guan_zhao_2011, title={A Coupled Atmosphere-Wave-Ocean Modeling System: Simulation of the Intensity of an Idealized Tropical Cyclone}, volume={139}, ISSN={["1520-0493"]}, DOI={10.1175/2010mwr3396.1}, abstractNote={Abstract}, number={1}, journal={MONTHLY WEATHER REVIEW}, author={Liu, Bin and Liu, Huiqing and Xie, Lian and Guan, Changlong and Zhao, Dongliang}, year={2011}, month={Jan}, pages={132–152} }
 @article{xie_liu_liu_bao_2011, title={A numerical study of the effect of hurricane wind asymmetry on storm surge and inundation}, volume={36}, ISSN={["1463-5011"]}, DOI={10.1016/j.ocemod.2010.10.001}, abstractNote={The influence of the asymmetric structure of hurricane wind field on storm surge is studied with five types of numerical experiments using a three-dimensional storm surge model. The results from the case of Hurricane Floyd (1999) show that Floyd-induced peak surge would have been much higher had the region of maximum wind rotated 30–90° counterclockwise. The idealized cases (the hypothetical hurricanes) with a wind speed asymmetry of 20 m s−1 show that the peak (negative) surge varied from 4.7 to 6.0 m (−5 to −5.7 m) or equivalent to −8.8% and 16.3% (2.8% and −10.4%) differences as compared to the control experiment. The area of flooding varied from 3552 to 3660 km2. The results from two other idealized cases of varying degree of wind speed asymmetry further show that with decreasing (increasing) asymmetry of wind fields, the variations of peak surge and peak negative surge caused by the rotation of wind fields decrease (increase) accordingly. The results suggest that in storm surge simulations forced by winds derived from balanced models, considerable uncertainty in storm surge and inundation can result from wind asymmetries. This is true even if all other storm parameters, including maximum wind speed, the radius of maximum winds (storm size), minimum central pressure, storm translation speed, drag coefficient, and model settings (domain size and resolution) are identical. Thus, when constructing ensemble and probabilistic storm surge forecasts, uncertainty in wind asymmetry should be considered in conjunction with variations in storm track, storm intensity and size.}, number={1-2}, journal={OCEAN MODELLING}, author={Xie, Lian and Liu, Huiqing and Liu, Bin and Bao, Shaowu}, year={2011}, pages={71–79} }
 @article{xia_xie_pietrafesa_whitney_2011, title={The ideal response of a Gulf of Mexico estuary plume to wind forcing: Its connection with salt flux and a Lagrangian view}, volume={116}, ISSN={["2169-9291"]}, DOI={10.1029/2010jc006689}, abstractNote={[1] The plume structure of Perdido Bay Estuary (PBE), a typical bay on the Florida-Alabama coast along the Gulf of Mexico, was simulated using an existing calibrated model. To better understand plume dynamics in the PBE and similar bay systems, idealized sensitivity experiments were conducted to examine the influence of wind stress on the 3-D plume signature: the results indicate that wind speed and direction significantly influence plume orientation, area, width, length, and depth. The plume size was reduced under the effect of wind and increased wind forcing. Among wind-forced cases, the plume is largest for northerly (offshore) winds and smallest for southerly (onshore) winds. Bay-shelf salt flux and water flux were also investigated, since they are important for the formation of a 3-D plume structure. Model simulations show that water outflow to the coastal ocean is strongest under northerly winds and can be stopped by southerly winds. For moderately strong winds, the outflow and plume size are larger for easterly downwelling-favorable winds than for westerly upwelling-favorable winds; the opposite is true for outflow and plume size for these two wind directions under stronger winds. For all wind directions, the ratio of salt flux and water flux at the bay mouth increases with wind speed. This ratio trend is consistent with higher outflow salinities, and this decreased buoyancy signature, along with more energetic vertical mixing, reduces plume size. A detailed understanding of this water and salt flux is essential to the plume dynamics studied here and for other plumes. Additional particle transport analysis using variable wind forcing was conducted to determine the influence of the plume on particle movement. The results showed a consistency between the surface plume, salt flux, and particle transport and illustrate the strong effects that winds have on particle fate and dispersion.}, journal={JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS}, author={Xia, Meng and Xie, Lian and Pietrafesa, Leonard J. and Whitney, Michael M.}, year={2011}, month={Aug} }
 @article{zha_xie_2010, title={A practical Bi-parameter Formula of Gas Transfer Velocity Depending on Wave States}, volume={66}, DOI={10.1007/s10872-010-0054-4}, number={5}, journal={Journal of Oceanography}, author={Zha, D. L. and Xie, L. A.}, year={2010}, pages={663–671} }
 @article{zhao_xie_2010, title={A practical bi-parameter formula of gas transfer velocity depending on wave states}, volume={10}, number={7}, journal={Journal of Soils and Sediments}, author={Zhao, D. L. and Xie, L. A.}, year={2010}, pages={663–671} }
 @article{peng_xie_liu_semazzi_2010, title={Application of Scale-Selective Data Assimilation to Regional Climate Modeling and Prediction}, volume={138}, ISSN={["1520-0493"]}, DOI={10.1175/2009mwr2974.1}, abstractNote={Abstract}, number={4}, journal={MONTHLY WEATHER REVIEW}, author={Peng, Shiqiu and Xie, Lan and Liu, Bin and Semazzi, Fredrick}, year={2010}, month={Apr}, pages={1307–1318} }
 @article{xie_liu_peng_2010, title={Application of scale-selective data assimilation to tropical cyclone track simulation}, volume={115}, ISSN={["2169-8996"]}, DOI={10.1029/2009jd013471}, abstractNote={Tropical cyclone track is strongly controlled by the large‐scale environmental circulation. In limited‐area models (LAMs) driven by global analyses or forecasts through a conventional lateral boundary nesting approach, the global analyses are often distorted by the use of “sponge zone” or interpolation when they are passed into the LAM. In this study, a dynamical downscaling approach based on scale‐selective data assimilation (SSDA) is applied to a limited‐area numerical weather prediction model with emphasis on tropical cyclone track simulation. The idea of the SSDA approach is to drive the LAM not only from the lateral boundary but also from the model domain interior. The large‐scale flow from global analyses or forecasts is assimilated into the regional model using 3‐D variational data assimilation. The large‐scale features in the LAM are thus constrained to follow the global analyses while allowing the regional model itself to develop the regional and small‐scale characteristics. The results from the case study of Hurricane Katrina (2005) show that both large‐ and small‐scale flows in the regional model benefited from the SSDA approach, leading to an improvement in the accuracy of storm track simulation when provided with an accurate large‐scale circulation from global analyses. In addition, the SSDA procedure is shown to be an effective method to construct a nested‐grid regional modeling system that reduces model sensitivity to model domain geometry and location.}, journal={JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES}, author={Xie, Lian and Liu, Bin and Peng, Shiqiu}, year={2010}, month={Sep} }
 @article{eggleston_reyns_etherington_plaia_xie_2010, title={Tropical storm and environmental forcing on regional blue crab (Callinectes sapidus) settlement}, volume={19}, ISSN={["1365-2419"]}, DOI={10.1111/j.1365-2419.2009.00530.x}, abstractNote={Abstract}, number={2}, journal={FISHERIES OCEANOGRAPHY}, author={Eggleston, David B. and Reyns, Nathalie B. and Etherington, Lisa L. and Plaia, Gayle R. and Xie, Lian}, year={2010}, pages={89–106} }
 @article{xia_xie_pietrafesa_2010, title={Winds and the orientation of a coastal plane estuary plume}, volume={37}, ISSN={["0094-8276"]}, DOI={10.1029/2010gl044494}, abstractNote={Based on a calibrated coastal plane estuary plume model, ideal model hindcasts of estuary plumes are used to describe the evolution of the plume pattern in response to river discharge and local wind forcing by selecting a typical partially mixed estuary (the Cape Fear River Estuary or CFRE). With the help of an existing calibrated plume model, as described by Xia et al. (2007), simulations were conducted using different parameters to evaluate the plume behavior type and its change associated with the variation of wind forcing and river discharge. The simulations indicate that relatively moderate winds can mechanically reverse the flow direction of the plume. Downwelling favorably wind will pin the plume to the coasts while the upwelling plume could induce plume from the left side to right side in the application to CFRE. It was found that six major types of plumes may occur in the estuary and in the corresponding coastal ocean. To better understand these plumes in the CFRE and other similar river estuary systems, we also investigated how the plumes transition from one type to another. Results showed that wind direction, wind speed, and sometimes river discharge contribute to plume transitions.}, journal={GEOPHYSICAL RESEARCH LETTERS}, author={Xia, Meng and Xie, Lian and Pietrafesa, Leonard J.}, year={2010}, month={Oct} }
 @article{liu_xie_2009, title={A numerical study on the effects of wave-current-surge interactions on the height and propagation of sea surface waves in Charleston Harbor during Hurricane Hugo 1989}, volume={29}, ISSN={["0278-4343"]}, DOI={10.1016/j.csr.2009.03.013}, abstractNote={The effects of wave–current interactions on ocean surface waves induced by Hurricane Hugo in and around the Charleston Harbor and its adjacent coastal waters are examined by using a three-dimensional (3D) wave–current coupled modeling system. The 3D storm surge modeling component of the coupled system is based on the Princeton Ocean Model (POM), the wave modeling component is based on the third generation wave model, Simulating WAves Nearshore (SWAN), and the inundation model is adopted from [Xie, L., Pietrafesa, L. J., Peng, M., 2004. Incorporation of a mass-conserving inundation scheme into a three-dimensional storm surge model. J. Coastal Res., 20, 1209–1223]. The results indicate that the change of water level associated with the storm surge is the primary cause for wave height changes due to wave–surge interaction. Meanwhile, waves propagating on top of surge cause a feedback effect on the surge height by modulating the surface wind stress and bottom stress. This effect is significant in shallow coastal waters, but relatively small in offshore deep waters. The influence of wave–current interaction on wave propagation is relatively insignificant, since waves generally propagate in the direction of the surface currents driven by winds. Wave–current interactions also affect the surface waves as a result of inundation and drying induced by the storm. Waves break as waters retreat in regions of drying, whereas waves are generated in flooded regions where no waves would have occurred without the flood water.}, number={11-12}, journal={CONTINENTAL SHELF RESEARCH}, author={Liu, Huiqing and Xie, Lian}, year={2009}, month={Jun}, pages={1454–1463} }
 @article{deng_xie_liu_wu_zhao_yu_2009, title={Coupling winds to ocean surface currents over the global ocean}, volume={29}, ISSN={["1463-5011"]}, DOI={10.1016/j.ocemod.2009.05.003}, abstractNote={A Wind stress–Current Coupled System (WCCS) consisting of the HYbrid Coordinate Ocean Model (HYCOM) and an improved wind stress algorithm based on Donelan et al. [Donelan, W.M., Drennan, Katsaros, K.B., 1997. The air–sea momentum flux in mixed wind sea and swell conditions. J. Phys. Oceanogr. 27, 2087–2099] is developed by using the Earth System Modeling Framework (ESMF). The WCCS is applied to the global ocean to study the interactions between the wind stress and the ocean surface currents. In this study, the ocean surface current velocity is taken into consideration in the wind stress calculation and air–sea heat flux calculation. The wind stress that contains the effect of ocean surface current velocity will be used to force the HYCOM. The results indicate that the ocean surface velocity exerts an important influence on the wind stress, which, in turn, significantly affects the global ocean surface currents, air–sea heat fluxes, and the thickness of ocean surface boundary layer. Comparison with the TOGA TAO buoy data, the sea surface temperature from the wind–current coupled simulation showed noticeable improvement over the stand-alone HYCOM simulation.}, number={4}, journal={OCEAN MODELLING}, author={Deng, Zengan and Xie, Lian and Liu, Bin and Wu, Kejian and Zhao, Dongliang and Yu, Ting}, year={2009}, pages={261–268} }
 @article{davis_bowden_semazzi_xie_onol_2009, title={Customization of RegCM3 Regional Climate Model for Eastern Africa and a Tropical Indian Ocean Domain}, volume={22}, ISSN={["1520-0442"]}, url={http://dx.doi.org/10.1175/2009jcli2388.1}, DOI={10.1175/2009JCLI2388.1}, abstractNote={Abstract}, number={13}, journal={JOURNAL OF CLIMATE}, author={Davis, Neil and Bowden, Jared and Semazzi, Fredrick and Xie, Lian and Onol, Baris}, year={2009}, month={Jul}, pages={3595–3616} }
 @article{keith_xie_2009, title={Predicting Atlantic Tropical Cyclone Seasonal Activity in April}, volume={24}, ISSN={["1520-0434"]}, DOI={10.1175/2008WAF2222139.1}, abstractNote={Abstract}, number={2}, journal={WEATHER AND FORECASTING}, author={Keith, Elinor and Xie, Lian}, year={2009}, month={Apr}, pages={436–455} }
 @article{sweet_morrison_liu_kamykowski_schaeffer_xie_banks_2009, title={Tropical instability wave interactions within the Galapagos Archipelago}, volume={56}, ISSN={["1879-0119"]}, DOI={10.1016/j.dsr.2009.02.005}, abstractNote={Abstract The effects of tropical instability waves (TIW) within the eastern equatorial Pacific during the boreal fall of 2005 were observed in multiple data sets. The TIW cause oscillations of the sea surface temperature (SST), meridional currents ( V ), and 20 °C isotherm (thermocline). A particularly strong 3-wave packet of ∼15-day period TIW passed through the Galapagos Archipelago in Sep and Oct 2005 and their effects were recorded by moored near-surface sensors. Repeat Argo profiles in the archipelago showed that the large temperature (>5 °C) oscillations that occurred were associated with a vertical adjustment within the water column. Numerical simulations report strong oscillations and upwelling magnitudes of ∼5.0 m d −1 near the Tropical Atmosphere Ocean (TAO) buoy at 0°, 95°W and in the Archipelago at 92°W and 90°W. A significant biological response to the TIW passage was observed within the archipelago. Chlorophyll a measured by the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) increased by >30% above 1998–2007 mean concentrations within the central archipelago. The increases coincide with coldest temperatures and the much larger increases within the archipelago as compared to those of 95°W indicate that TIW induced upwelling over the island platform itself brought more iron-enriched upwelling waters into the euphotic zone.}, number={8}, journal={DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS}, author={Sweet, W. V. and Morrison, J. M. and Liu, Y. and Kamykowski, D. and Schaeffer, B. A. and Xie, L. and Banks, S.}, year={2009}, month={Aug}, pages={1217–1229} }
 @article{lynch_lestak_uotila_cassano_xie_2008, title={A factorial analysis of storm surge flooding in Barrow, Alaska}, volume={136}, ISSN={["0027-0644"]}, DOI={10.1175/2007MWR2121.1}, abstractNote={Abstract}, number={3}, journal={MONTHLY WEATHER REVIEW}, author={Lynch, Amanda H. and Lestak, Leanne R. and Uotila, Petteri and Cassano, Elizabeth N. and Xie, Lian}, year={2008}, month={Mar}, pages={898–912} }
 @article{xia_xie_pietrafesa_peng_2008, title={A numerical study of storm surge in the Cape Fear River Estuary and adjacent coast}, volume={24}, ISSN={["1551-5036"]}, DOI={10.2112/06-0795.1}, abstractNote={Abstract The Cape Fear River Estuary (CFRE) region is a coastal domain that has experienced considerable threats and impacts from tropical cyclones. It is also an important nursery for juvenile fish, crabs, shrimp, and other biological species. Thus, predictions about the physical responses of the CFRE system to extreme weather events are important to the protection of life and property and to the economical well-being of local residents. In this study, the Princeton Ocean Model (POM) is used to simulate tropical cyclone storm–induced surge, inundation, and coastal circulation in the CFRE and the adjacent Long Bay using a three-level nesting approach. Hindcasts of the hydrodynamic responses of the CFRE system to historic events were performed for Hurricanes Fran, Floyd, Bertha, and Charley. Comparisons were also made for the modeling results and the observations.}, number={4C}, journal={JOURNAL OF COASTAL RESEARCH}, author={Xia, Meng and Xie, Lian and Pietrafesa, Leonard J. and Peng, Machuan}, year={2008}, pages={159–167} }
 @article{xu_xie_cheng_xu_zhou_ding_2008, title={Application of an adaptive nudging scheme in air quality forecasting in China}, volume={47}, ISSN={["1558-8424"]}, DOI={10.1175/2008JAMC1737.1}, abstractNote={Abstract}, number={8}, journal={JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY}, author={Xu, Xiangde and Xie, Lian and Cheng, Xinghong and Xu, Jianming and Zhou, Xiuji and Ding, Guoan}, year={2008}, month={Aug}, pages={2105–2114} }
 @article{xiaohui_xiangde_lian_2008, title={Characteristics of climate change in the "significant impact zone" affected by aerosols over eastern China in warm seasons}, volume={51}, ISSN={["1006-9313"]}, DOI={10.1007/s11430-008-0044-1}, number={5}, journal={SCIENCE IN CHINA SERIES D-EARTH SCIENCES}, author={XiaoHui, Shi and XiangDe, Xu and LiAn, Xie}, year={2008}, month={May}, pages={730–739} }
 @article{schaeffer_morrison_kamykowski_feldman_xie_liu_sweet_mcculloch_banks_2008, title={Phytoplankton biomass distribution and identification of productive habitats within the Galapagos Marine Reserve by MODIS, a surface acquisition system, and in-situ measurements}, volume={112}, ISSN={["1879-0704"]}, DOI={10.1016/j.rse.2008.03.005}, abstractNote={The Galapagos Marine Reserve (GMR) is one of the most diverse ecosystems in the world. Phytoplankton are the base of the ecosystem food chain for many higher trophic organisms, so identifying phytoplankton biomass distribution is the first step in understanding the dynamic environment for effective management of the GMR. Moderate Resolution Imaging Spectroradiometer (MODIS) and hyperspectral surface acquisition system derived chlorophyll, in-situ chlorophyll fluorescence, nitrate, salinity, and temperature were collected from March 2005 to the onset of a mild El Niño in November 2006. Islands in the eastern GMR, such as San Cristobal and Espanola, are the first to experience impacts of El Niño and southern migration of the Equatorial Front. Productive habitats were defined as surface waters with salinities > 34, temperatures < 24 °C, and chlorophyll a > 0.4 mg m− 3. Six temporally variable productive habitats identified were: west of Isabela Island, southwest of Floreana Island, south of Santa Cruz, between Santiago and Santa Cruz Islands, and on the eastern side near San Cristobal Island. Model results coupled with surface acquisition system derived chlorophyll indicated productive habitats may also occur for short periods and at a distance from islands such as when the Equatorial Undercurrent (EUC) and South Equatorial Current (SEC) collide over the seamounts north of Isabela Island. All productive habitats were related to topographic upwelling from the EUC into surface waters.}, number={6}, journal={REMOTE SENSING OF ENVIRONMENT}, author={Schaeffer, Blake A. and Morrison, John M. and Kamykowski, Daniel and Feldman, Gene C. and Xie, Lian and Liu, Yanyun and Sweet, William and McCulloch, Anita and Banks, Stuart}, year={2008}, month={Jun}, pages={3044–3054} }
 @article{xie_liu_peng_2008, title={The effect of wave-current interactions on the storm surge and inundation in Charleston Harbor during Hurricane Hugo 1989}, volume={20}, ISSN={["1463-5011"]}, DOI={10.1016/j.ocemod.2007.10.001}, abstractNote={The effects of wave–current interactions on the storm surge and inundation induced by Hurricane Hugo in and around the Charleston Harbor and its adjacent coastal regions are examined by using a three-dimensional (3-D) wave–current coupled modeling system. The 3-D storm surge and inundation modeling component of the coupled system is based on the Princeton ocean model (POM), whereas the wave modeling component is based on the third-generation wave model, simulating waves nearshore (SWAN). The results indicate that the effects of wave-induced surface, bottom, and radiation stresses can separately or in combination produce significant changes in storm surge and inundation. The effects of waves vary spatially. In some areas, the contribution of waves to peak storm surge during Hurricane Hugo reached as high as 0.76 m which led to substantial changes in the inundation and drying areas simulated by the storm surge model.}, number={3}, journal={OCEAN MODELLING}, author={Xie, Lian and Liu, Huiqing and Peng, Machuan}, year={2008}, pages={252–269} }
 @article{lin_xie_pietrafesa_xu_woods_mallin_durako_2008, title={Water quality responses to simulated flow and nutrient reductions in the Cape Fear River Estuary and adjacent coastal region, North Carolina}, volume={212}, ISSN={["1872-7026"]}, DOI={10.1016/j.ecolmodel.2007.10.026}, abstractNote={In order to examine system responses to high river discharge events and nutrient loading variations from the drainage basin, a coupled three-dimensional hydrodynamic and water quality model was applied in the Cape Fear River Estuary (CFRE) and its adjacent coastal region. An empirical equation was introduced in the model to represent light limitation for phytoplankton growth due to chromophoric dissolved organic matter (CDOM). Model results show that in the upper to middle estuary, light limitation controls phytoplankton growth while in the lower estuary phytoplankton growth appears to be limited by light intensity during high flow periods, but by nutrient availability during low flow periods. In the coastal ocean, nutrient availability is usually the dominant limiting factor for primary production. Two sensitivity model tests were conducted to predict the system response to reductions in nutrient loading from the drainage basin. By reducing river discharge, the model results show that phytoplankton growth was enhanced within CFRE due to alleviated light limitation and increased residence time. More nutrients were consumed within the CFRE, and less were exported to the coastal region. By reducing nutrient concentrations at the head of the estuary, chlorophyll a concentrations within the CFRE were decreased. Less nutrients were consumed within the CFRE, and only slightly less were exported to the coastal region. The supply of light limiting substances during high flow events acted against the effect of riverine nutrient enhancement on phytoplankton growth, creating a negative feedback mechanism.}, number={3-4}, journal={ECOLOGICAL MODELLING}, author={Lin, Jing and Xie, Lian and Pietrafesa, Leonard J. and Xu, Honqzhou and Woods, Wendy and Mallin, Michael A. and Durako, Michael J.}, year={2008}, month={Apr}, pages={200–217} }
 @article{xu_shi_xie_wang_2007, title={Consistency of interdecadal variation in the summer monsoon over eastern China and heterogeneity in springtime surface air temperatures}, volume={85A}, ISSN={["2186-9057"]}, DOI={10.2151/jmsj.85A.311}, abstractNote={This study investigates the consistency of interdecadal variations in the East Asian summer monsoon (EASM) and changes in the heterogeneous structure of sealland springtime surface air temperature (SAT) over eastern China and the adjacent ocean (including the South China Sea and part of the Western Pacific Ocean). A profile of the summer mean meridional wind over eastern China for the past 40 years shows a coherent interdecadal weakening trend for the EASM. The decadal-scale (11-year running mean) summertime (June-August) wind and springtime (March-May) SAT fields are decomposed using the empirical orthogonal function (EOF) method. The results indicate that both the leading eigen-vector of the decadal-scale meridional wind and that for the SAT over East Asia account for more than 70% of the total variance. Their time coefiicients show a similar trend, with the transition from negative to positive values occurring around 1978; i.e., the EASM turned from a stronger phase to a weaker phase around 1978. The springtime sealland SAT distribution before and after 1978 also showed a shift in interdecadal trends. Therefore, the south-lowlnorth-high nature of the principal component of springtime SAT over eastern China is closely related to the progressive weakening of the EASM. Our results suggest that within the context of the regional impact of global climate change, heterogeneous changes in the regional springtime sea/land SAT in eastern Asia might in part have led to a weakening of the effect of sealland thermal driving on the EASM.}, journal={JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN}, author={Xu, Xiangde and Shi, Xiaohui and Xie, Lian and Wang, Yafei}, year={2007}, month={Feb}, pages={311–323} }
 @article{peng_xie_pietrafesa_2007, title={Correcting the errors in the initial conditions and wind stress in storm surge simulation using an adjoint optimal technique}, volume={18}, DOI={10.1016/j.ocemod.2007.04.002}, abstractNote={An adjoint data assimilation methodology is applied to the Princeton Ocean Model and is evaluated by obtaining “optimal” initial conditions, sea surface forcing conditions, or both for coastal storm surge modelling. By prescribing different error sources and setting the corresponding control variables, we performed several sets of identical twin experiments by assimilating model-generated water levels. The experiment results show that, when the forecasting errors are caused by the initial (or surface boundary) conditions, adjusting initial (or surface boundary) conditions accordingly can significantly improve the storm surge simulation. However, when the forecasting errors are caused by surface boundary (or initial) conditions, data assimilation targeting improving the initial (or surface boundary) conditions is ineffective. When the forecasting errors are caused by both the initial and surface boundary conditions, adjusting both the initial and surface boundary conditions leads to the best results. In practice, we do not know whether the errors are caused by initial conditions or surface boundary conditions, therefore it is better to adjust both initial and surface boundary conditions in adjoint data assimilation.}, number={3-4}, journal={Ocean Modelling (Oxford, England)}, author={Peng, S. Q. and Xie, L. and Pietrafesa, L. J.}, year={2007}, pages={175–193} }
 @article{xie_liu_pietrafesa_2007, title={Effect of bathymetric curvature on gulf stream instability in the vicinity of the Charleston Bump}, volume={37}, ISSN={["0022-3670"]}, DOI={10.1175/JPO2995.1}, abstractNote={Abstract}, number={3}, journal={JOURNAL OF PHYSICAL OCEANOGRAPHY}, author={Xie, Lian and Liu, Xiaoming and Pietrafesa, Leonard J.}, year={2007}, month={Mar}, pages={452–475} }
 @article{xia_xie_pietrafesa_2007, title={Modeling of the Cape Fear River Estuary plume}, volume={30}, ISSN={["1559-2731"]}, DOI={10.1007/BF02841966}, number={4}, journal={ESTUARIES AND COASTS}, author={Xia, Meng and Xie, Lian and Pietrafesa, Leonard J.}, year={2007}, month={Aug}, pages={698–709} }
 @article{pietrafesa_buckley_peng_bao_liu_peng_xie_dickey_2007, title={On coastal ocean systems, coupled model architectures, products and services: Morphing from observations to operations and applications}, volume={41}, ISSN={["1948-1209"]}, DOI={10.4031/002533207787442268}, abstractNote={The national build-up of “coastal ocean observing systems” (COOSs) to establish the coastal observing component of the national component of the Integrated Ocean Observing System (IOOS) network must be well organized and must acknowledge, understand and address the needs
 of the principal clients, the federal, and in some cases state as well, agencies that provide financial support if it is to have substantive value. The funds being spent in support of COOS should be invested in pursuit of the establishment of the National Backbone (NB) that is needed: to greatly
 improve atmospheric, oceanic and coastal “weather” forecasting, broadly defined; for ecosystem management; and to document climate variability and change in coastal zones. However, this process has not occurred in a well conceived, orderly, well integrated manner due to historical
 and cultural bases and because of local priorities. A sub-regional effort that is designed to meet federal agency needs and mission responsibilities with an emphasis on meeting societal needs is presented by way of example to show that university and industry partners with federal agencies
 have an important role to play in the future of building out ocean and coastal observing and prediction systems and networks.}, number={1}, journal={MARINE TECHNOLOGY SOCIETY JOURNAL}, author={Pietrafesa, L. J. and Buckley, E. B. and Peng, M. and Bao, S. and Liu, H. and Peng, S. and Xie, L. and Dickey, D. A.}, year={2007}, pages={44–52} }
 @article{shi_xu_xie_2007, title={Reliability analyses of anomalies of NCEP/NCAR reanalyzed wind speed and surface air temperature in climate change research in China}, volume={21}, number={3}, journal={Acta Meteorologica Sinica}, author={Shi, X. H. and Xu, X. D. and Xie, L. A.}, year={2007}, pages={320–333} }
 @article{liu_xie_pietrafesa_bao_2007, title={Sensitivity of wind waves to hurricane wind characteristics}, volume={18}, ISSN={["1463-5003"]}, DOI={10.1016/j.ocemod.2007.03.004}, abstractNote={In this study, the influence of the spatial and temporal variability of hurricane winds, storm translation speed, intensity, and ambient wind field on surface wind waves are investigated by using a third-generation wave model (Simulating WAves Nearshore, or SWAN). The results show that the asymmetric structure of wind-induced wave field is sensitive not only to the asymmetric structure of the hurricane wind field, but also to the variations in the storm translation speed and intensity. The significant wave height (SWH) in the front-right quadrant of the storm rises as storm translation speed increases until it reaches a critical value, then the SWH drops. The opposite occurs in the rear-left quadrant. The total contribution of the hurricane translation speed to the asymmetric structure of the wave field also depends on the intensity of the hurricane. As the intensity of the hurricane increases, the relative significance of the influence of the translation speed on the asymmetric structure of the wave field decreases. Most parametric hurricane wind models can only model symmetric hurricanes and do not include background winds. However, actual hurricanes in nature are not only asymmetric but also imbedded in background winds. Thus, to more properly model hurricane-induced wave field, it is important to consider storm asymmetry, translation speed, intensity, as well as background winds.}, number={1}, journal={OCEAN MODELLING}, author={Liu, Huiqing and Xie, Lian and Pietrafesa, Leonard J. and Bao, Shaowu}, year={2007}, pages={37–52} }
 @article{lin_xie_pietrafesa_ramus_paerl_2007, title={Water quality gradients across Albemarle-Pamlico estuarine system: Seasonal variations and model applications}, volume={23}, ISSN={["1551-5036"]}, DOI={10.2112/05-0507.1}, abstractNote={Abstract The seasonal variations of water quality parameters as nitrite plus nitrate (NO−;x), total phosphate (PO3−4), chlorophyll a (chl a), and dissolved oxygen (DO) are analyzed across the Croatan-Roanoke-Albemarle-Pamlico-Core Sounds estuarine system (CAPES). Overall, several patterns are observed: The Chowan-Roanoke-Albemarle system is generally phosphorous limiting for phytoplankton growth, whereas both the Tar-Pamlico and the Neuse Rivers are generally nitrogen limiting. The largest PO3−4 gradients exist in the upstream portion of the Albemarle Sound, and the largest NO−x gradients exist in the lower Neuse and the Tar-Pamlico Rivers. Dissolved oxygen appears to have the strongest seasonal signal among the water quality variables, with highest DO values observed during winter (within the CAPES and in the nearshore area) or spring (in the continental shelf and deeper ocean) and lowest during summer. Chlorophyll a concentrations are highest during spring (within the CAPES) or winter (offshore). In contrast, the NOx− and PO3−4 concentrations in both the Tar-Pamlico and Neuse River estuaries are usually higher during the second half of the year. The time differences of the peak nutrient and chl a concentrations suggest that highest algal growth rate (and hence nutrient uptake rate) occurs during spring, and the consumed nutrients are released to the water column through a nutrient recycling method later in the year. A coupled three-dimensional hydrodynamic water quality model is then applied to the entire system. The general model setup and parameter derivation of the model is presented here. The basic observed water quality characteristics such as the nutrient limiting pattern and the spatial gradients across the system are reproduced in the model. The model results also suggest that nutrient fluxes, generated from the diagenesis of deposited organic matter and released from the sediment bed, could be an important mechanism for nutrient recycling in the region.}, number={1}, journal={JOURNAL OF COASTAL RESEARCH}, author={Lin, Jing and Xie, Lian and Pietrafesa, Leonard J. and Ramus, Joseph S. and Paerl, Hans W.}, year={2007}, month={Jan}, pages={213–229} }
 @article{xie_yan_2007, title={West North Pacific typhoon track patterns and their potential connection to Tibetan Plateau snow cover}, volume={42}, ISSN={["1573-0840"]}, DOI={10.1007/s11069-006-9087-9}, number={2}, journal={NATURAL HAZARDS}, author={Xie, Lian and Yan, Tingzhuang}, year={2007}, month={Aug}, pages={317–333} }
 @article{xu_xie_zhang_yao_2006, title={A mathematical model for forecasting tropical cyclone tracks}, volume={7}, ISSN={["1468-1218"]}, DOI={10.1016/j.nonrwa.2004.04.004}, abstractNote={The kinematics and dynamics of tropical cyclone (TC) tracks are studied by using a mathematical model of track curvature. The results indicate that the curvature of storm track is determined by a set of ‘controlling parameters’ related to the storm characteristics and the ambient atmospheric circulation. These controlling parameters include the speed of storm motion, storm intensity and size, the Coriolis parameter, ambient atmospheric pressure field, and surface friction. In northern hemisphere, a northward moving TC tends to gain anti-cyclonic curvature and deflect to the right. A westward or northwestward moving TC will also deflect to the right when it slows down. A westward-moving TC along the southern edge of the sub-tropical high tends to deflect to the right as it moves toward the “turning point” of the large scale flow field (i.e. the southwest corner of the subtropical high). An eastward-moving TC along the northern edge of the sub-tropical high tends to deflect leftward toward the low-pressure side of the steering flow. A TC located in front of a westerly trough will gain cyclonic curvature. Thus, a re-curving TC after passing its western most location will tend to deflect to the low-pressure side. Finally, TC intensity and size change can also affect the TC movement. For example, a westward moving, deepening or enlarging TC tends to move anti-cyclonically.}, number={2}, journal={NONLINEAR ANALYSIS-REAL WORLD APPLICATIONS}, author={Xu, XD and Xie, LA and Zhang, XJ and Yao, WQ}, year={2006}, month={Apr}, pages={211–224} }
 @article{pietrafesa_kelleher_karl_davidson_peng_bao_dickey_xie_liu_xia_2006, title={A new architecture for coastal inundation and flood warning prediction}, volume={40}, ISSN={["0025-3324"]}, DOI={10.4031/002533206787353205}, abstractNote={The marine atmosphere, coastal ocean, estuary, harbor and river water systems constitute a physically coupled system. While these systems have always been heavily impacted by coastal storms, increases in population density, infrastructure, and personal and business merchandise have
 exacerbated the economic and personal impacts of these events over the past half century. As such there has been increased focus on the need for more timely and accurate forecasts of impending events. Traditionally model forecast architectures for coastal storm surge, flooding and inundation
 of coastal and inland areas have taken the approach of dealing with each system separately: rivers, estuaries, harbors and offshore facing areas. However, given advances in coupled modeling and the availability of real-time data, the ability to accurately predict and project coastal, estuary
 and inland flooding related to the passage of high energy and wet atmospheric events is rapidly emerging and requires a new paradigm in system architecture. No longer do monthly averaged winds or river discharge or water levels have to be invoked in developing hindcasts for planning purposes
 or for real-time forecasts. In 1999 a hurricane associated flood on the North Carolina coast took 56 lives and caused more than $6 billion in economic impacts. None of the models existing at that time were able to properly forecast the massive flooding and clearly called for a new model
 paradigm. Here we propose a model system that couples atmospheric information to fully three dimensional, non-linear time dependent ocean basin, coastal and estuary hydrodynamic models coupled to interactive river models with input of real or modeled winds, observed or modeled precipitation,
 measured and modeled water levels, and streamflow. The river and estuarine components must both be capable of going into modes of storage or accelerated discharge. Spatial scales must downscale in the horizontal from thousands to tens meters and in the vertical from hundreds to several centimeters.
 Topography and elevation data should be of the highest resolution available, necessary for highly accurate predictions of the timing and location of the inundation and retreat of flood waters. Precipitation information must be derived from the optimal mix of direct radar, satellite and ground-based
 observations. Creating the capability described above will advance the modernization of hydrologic services provided by the National Oceanic & Atmospheric Administration and provide more accurate and timely forecasts and climatologies of coastal and estuary flooding. The goal of these
 climatologies and improved forecasts is to provide better information to local and regional planners, emergency managers, highway patrols and to improve the capacity of coastal communities to mitigate against the impacts of coastal flooding.}, number={4}, journal={MARINE TECHNOLOGY SOCIETY JOURNAL}, author={Pietrafesa, L. J. and Kelleher, K. and Karl, T. and Davidson, M. and Peng, M. and Bao, S. and Dickey, D. and Xie, L. and Liu, H. and Xia, M.}, year={2006}, pages={71–77} }
 @article{peng_xie_pietrafesa_2006, title={A numerical study on hurricane-induced storm surge and inundation in Charleston Harbor, South Carolina}, volume={111}, ISSN={["2169-9291"]}, DOI={10.1029/2004jc002755}, abstractNote={A storm surge and inundation model is configured in Charleston Harbor and its adjacent coastal region to study the harbor's response to hurricanes. The hydrodynamic component of the modeling system is based on the Princeton Ocean Model, and a scheme with multiple inundation speed options is imbedded in the model for the inundation calculation. Historic observations (Hurricane Hugo and its related storm surge and inundation) in the Charleston Harbor region indicate that among three possible inundation speeds in the model, taking Ct (gd)1/2 (Ct is a terrain‐related parameter) as the inundation speed is the best choice. Choosing a different inundation speed in the model has effects not only on inundation area but also on storm surge height. A nesting technique is necessary for the model system to capture the mesoscale feature of a hurricane and meanwhile to maintain a higher horizontal resolution in the harbor region, where details of the storm surge and inundation are required. Hurricane‐induced storm surge and inundation are very sensitive to storm tracks. Twelve hurricanes with different tracks are simulated to investigate how Charleston Harbor might respond to tracks that are parallel or perpendicular to the coastline or landfall at Charleston at different angles. Experiments show that large differences of storm surge and inundation may have occurred if Hurricane Hugo had approached Charleston Harbor with a slightly different angle. A hurricane's central pressure, radius of maximum wind, and translation speed have their own complicated effects on surge and inundation when the hurricane approaches the coast on different tracks. Systematic experiments are performed in order to illustrate how each of such factors, or a combination of them, may affect the storm surge height and inundation area in the Charleston Harbor region. Finally, suggestions are given on how this numerical model system may be used for hurricane‐induced storm surge and inundation forecasting.}, number={C8}, journal={JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS}, author={Peng, Machuan and Xie, Lian and Pietrafesa, Leonard J.}, year={2006}, month={Aug} }
 @article{xie_bao_pietrafesa_foley_fuentes_2006, title={A real-time hurricane surface wind forecasting model: Formulation and verification}, volume={134}, ISSN={["0027-0644"]}, DOI={10.1175/MWR3126.1}, abstractNote={Abstract}, number={5}, journal={MONTHLY WEATHER REVIEW}, author={Xie, L and Bao, SW and Pietrafesa, LJ and Foley, K and Fuentes, M}, year={2006}, month={May}, pages={1355–1370} }
 @inproceedings{xia_xie_pietrafesa_2006, title={Cape Fear River Estuary Plume Modeling: Model Configuration and Sensitivity Experiments}, ISBN={9780784408766}, url={http://dx.doi.org/10.1061/40876(209)6}, DOI={10.1061/40876(209)6}, abstractNote={In this study, Environmental Fluid Dynamic Code (EFDC) is used to simulate the salinity plume distribution in the mouth of the Cape Fear River Estuary (CFRE). Effects of astronomical tide, river discharge and wind on the CFRE salinity plume were investigated. The spatial and temporal characteristics of the model simulated salinity plume are compared with observations measured by the Coastal Ocean Research and Monitoring Program (CORMP). The results indicate that model results and observations show a good agreement in water level and salinity. The simulations also indicate that strong winds tend to reduce the surface CFRE plume size and distorting the bulge region near the estuary mouth due to enhanced wind induced surface mixing. Even moderate wind speeds could fully reverse the buoyancy-driven plume structure in CFRE under normal river discharge conditions. Tide and the river. discharge also important factors ....}, booktitle={Estuarine and Coastal Modeling (2005)}, publisher={American Society of Civil Engineers}, author={Xia, Meng and Xie, Lian and Pietrafesa, Leonard J.}, year={2006}, month={Jul} }
 @article{lin_xie_pietrafesa_shen_mallin_durako_2006, title={Dissolved oxygen stratification in two micro-tidal partially-mixed estuaries}, volume={70}, ISSN={["1096-0015"]}, DOI={10.1016/j.ecss.2006.06.032}, abstractNote={The controlling physical factors for vertical oxygen stratification in micro-tidal, partially-mixed estuaries are discussed in this paper. A theoretical deduction shows that vertical stratification of dissolved oxygen (DO) concentration can be explained by the extended Hansen and Rattray's Central Region theory, which suggests that in addition to biological factors such as photosynthesis, biochemical oxygen demand (BOD), sediment oxygen demand (SOD), vertical DO profiles are mainly controlled by physical factors such as surface re-aeration, river flow, and estuarine gravitational circulation. Vertical mixing of DO from surface re-aeration and photosynthesis sets a DO profile of higher concentration near the surface and lower near the bottom. With a positive seaward longitudinal DO gradient, strong river flow and estuarine gravitational circulation can cause lower DO concentrations near the surface and higher near the bottom. The actual vertical oxygen profile is then determined by the relative magnitude of the above-mentioned mechanisms. It is sensitive to two parameters: (1) the strength of the gravitational circulation (uE); and (2) the relative importance between biochemical oxygen demand and vertical diffusivity (α). Vertical DO stratification usually becomes weaker as uE increases. The impact of gravitational circulation on vertical oxygen distribution becomes more important for a larger α. The impact of α on oxygen stratification is profound. As uE (and river flow) increases, DO stratification appears to be less sensitive to the value of α. Surface-to-bottom differences in DO concentrations (ΔDO) is negligible when α is small (α < 0.5). As α increases, ΔDO increases under a weak to moderate gravitational circulation mode (uE ≤ 5 cm s−1). Under a strong gravitational circulation mode, ΔDO becomes negative with a small α (α < 2), and as α continues to increase, ΔDO becomes positive. The newly-deduced governing equation for vertical oxygen stratification is applied to two micro-tidal, partially-mixed estuarine systems: the Cape Fear River Estuary (CFRE) and the Pamlico River Estuary (PRE) of North Carolina. In the CFRE, although strong vertical salinity stratification exists, DO concentrations are usually well mixed. De-coupling between salinity stratification and oxygen stratification is mainly due to a relatively stronger estuarine gravitational circulation and higher freshwater inflow in the system. It appears that river flow and gravitational circulation are the dominant factors in controlling oxygen stratification in the CFRE. In contrast, vertical stratification of DO concentrations is closely correlated with that of salinity in the PRE. In the PRE, the estuarine gravitational mode and river flow are often both very weak, and DO stratification is very sensitive to the value of α. With negligible influence from tidal mixing, the system is more sensitive to vertical mixing regulated by salinity stratification and wind. As a result, vertical DO stratification is closely correlated with salinity stratification in the PRE.}, number={3}, journal={ESTUARINE COASTAL AND SHELF SCIENCE}, author={Lin, Jing and Xie, Lian and Pietrafesa, Len J. and Shen, Jian and Mallin, Michael A. and Durako, Michael J.}, year={2006}, month={Nov}, pages={423–437} }
 @misc{peng_xie_2006, title={Effect of determining initial conditions by four-dimensional variational data assimilation on storm surge forecasting}, volume={14}, ISSN={["1463-5011"]}, DOI={10.1016/j.ocemod.2006.03.005}, abstractNote={A tangent linear model and an adjoint model of the three-dimensional, time-dependent, nonlinear Princeton Ocean Model (POM) are developed to construct a four-dimensional variational data assimilation (4D-Var) algorithm for coastal ocean prediction. To verify and evaluate the performance of this 4D-Var method, a suite of numerical experiments are conducted for a storm surge case using model-generated “pseudo-observations”. The pseudo-observations are generated by a nested-grid high-resolution numerical model which is coupled to an inundation/drying scheme that is not included in the original POM. The 4D-Var algorithm based on POM is tested thoroughly for both code accuracy and the potential application in storm surge forecasting. The assimilation cycles lead to effective convergence between the forecasts and the “observations”. Assimilating water level alone or together with surface currents both lead to significant improvements in storm surge forecasts within and several hours beyond the data assimilation window. It is worth noting that, assimilating water level alone produces improvements in storm surge forecasts that are comparable to those by assimilating both water level and surface currents, suggesting that optimizations of water level and surface currents are linked through the 4D-Var assimilation cycles. However, it is also worth noting that, the benefit resulting from the reduction of initial error in water level and/or surface currents through data assimilation decreases rapidly in time outside the assimilation window. This suggests that determining initial conditions of water level and/or surface currents via data assimilation is only effective within and a few hours beyond the assimilation window for storm surge forecasting. Thus, alternative data assimilation approaches are needed to improve the accuracy and lead time in operational storm surge forecasting.}, number={1-2}, journal={OCEAN MODELLING}, author={Peng, S. -Q. and Xie, L.}, year={2006}, pages={1–18} }
 @article{anyah_semazzi_xie_2006, title={Simulated physical mechanisms associated with climate variability over Lake Victoria basin in East Africa}, volume={134}, ISSN={["1520-0493"]}, DOI={10.1175/MWR3266.1}, abstractNote={Abstract}, number={12}, journal={MONTHLY WEATHER REVIEW}, author={Anyah, Richard O. and Semazzi, Fredrick H. M. and Xie, Lian}, year={2006}, month={Dec}, pages={3588–3609} }
 @article{peng_xie_pietrafesa_2006, title={Tropical cyclone induced asymmetry of sea level surge and fall and its presentation in a storm surge model with parametric wind fields}, volume={14}, ISSN={["1463-5011"]}, DOI={10.1016/j.ocemod.2006.03.004}, abstractNote={The asymmetry of tropical cyclone induced maximum coastal sea level rise (positive surge) and fall (negative surge) is studied using a three-dimensional storm surge model. It is found that the negative surge induced by offshore winds is more sensitive to wind speed and direction changes than the positive surge by onshore winds. As a result, negative surge is inherently more difficult to forecast than positive surge since there is uncertainty in tropical storm wind forecasts. The asymmetry of negative and positive surge under parametric wind forcing is more apparent in shallow water regions. For tropical cyclones with fixed central pressure, the surge asymmetry increases with decreasing storm translation speed. For those with the same translation speed, a weaker tropical cyclone is expected to gain a higher AI (asymmetry index) value though its induced maximum surge and fall are smaller. With fixed RMW (radius of maximum wind), the relationship between central pressure and AI is heterogeneous and depends on the value of RMW. Tropical cyclone’s wind inflow angle can also affect surge asymmetry. A set of idealized cases as well as two historic tropical cyclones are used to illustrate the surge asymmetry.}, number={1-2}, journal={OCEAN MODELLING}, author={Peng, Machuan and Xie, Lian and Pietrafesa, Leonard J.}, year={2006}, pages={81–101} }
 @article{xu_xie_ding_bian_2005, title={Beijing air pollution project to benefit 2008 Olympic Games}, volume={86}, ISSN={["1520-0477"]}, DOI={10.1175/BAMS-86-11-1543}, number={11}, journal={BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY}, author={Xu, XD and Xie, LA and Ding, GA and Bian, LG}, year={2005}, month={Nov}, pages={1543–1545} }
 @article{xie_yan_pietrafesa_morrison_karl_2005, title={Climatology and interannual variability of North Atlantic hurricane tracks}, volume={18}, ISSN={["0894-8755"]}, DOI={10.1175/jcli3560.1}, abstractNote={Abstract}, number={24}, journal={JOURNAL OF CLIMATE}, author={Xie, L and Yan, TZ and Pietrafesa, LJ and Morrison, JM and Karl, T}, year={2005}, month={Dec}, pages={5370–5381} }
 @inproceedings{pietrafesa_xie_dickey_2005, title={On Sea-Level Variability on the Eastern Seaboard of the United States}, ISBN={9780784407745}, url={http://dx.doi.org/10.1061/40774(176)5}, DOI={10.1061/40774(176)5}, abstractNote={Coastal inhabitants experience sea level rise and fall, hourly, daily, weekly, monthly, and yearly and so on, governed by the astronomical tides, and a host of other factors. Meanwhile, there has been an accelerated migration into these zones by the populace of the United States (US). The recent census of the US indicates that greater than 50% of the nation's population resides in the coastal zone including the Atlantic and Pacific seaboards, the Gulf of Mexico, the Great Lakes, Alaska and Hawaii. Accompanying and facilitating the migration has been property development which has been increasing at an increasing rate. Meanwhile, reports of sea level rise and thus encroachment of the coastal ocean into these developed areas is raising serious concerns. But, what are the rates of variability, and the overall trends, over local to regional to global spatial scales? These are questions which coastal scientists, managers, builders, planners, developers, residents, and public officials, amongst others, would like to have answered factually. And this point cannot be overemphasized. However, in order to properly answer the questions posed regarding future adjustments in sea level, we must know past and present rates of rise. In this report, we will delve into these questions attempt to provide factual estimates based on the actual records. We will focus on the eastern seaboard of the US from Atlantic City, New Jersey to Charleston, South Carolina.}, booktitle={Solutions to Coastal Disasters 2005}, publisher={American Society of Civil Engineers}, author={Pietrafesa, L. J. and Xie, L. and Dickey, D. A.}, year={2005}, month={May} }
 @article{xie_2005, title={Relationship between western North Pacific typhoon activity and Tibetan Plateau winter and spring snow cover}, volume={32}, ISSN={0094-8276}, url={http://dx.doi.org/10.1029/2005GL023237}, DOI={10.1029/2005GL023237}, abstractNote={The annual frequency of western North Pacific (WNP) typhoons and the number of landfall typhoons in China are shown to negatively correlate with the Tibetan Plateau snow cover (TP‐SC) during the preceding winter and spring. When TP‐SC was above normal, fewer typhoons formed in the WNP and made landfall in China, and vice versa. The observed seasonal lag correlation between the TP‐SC and the WNP typhoon activity suggests the existence of a seasonal memory of the East Asia – West Pacific regional climate system which provides a means for the seasonal prediction of WNP typhoon activity and typhoon landfall frequency in China.}, number={16}, journal={Geophysical Research Letters}, publisher={American Geophysical Union (AGU)}, author={Xie, Lian}, year={2005} }
 @article{xie_yan_pietrafesa_karl_xu_2005, title={Relationship between western North Pacific typhoon activity and Tibetan Plateau winter and spring snow cover}, volume={32}, number={16}, journal={Geophysical Research Letters}, author={Xie, L. and Yan, T. Z. and Pietrafesa, L. J. and Karl, T. and Xu, X. D.}, year={2005} }
 @article{xu_shi_xie_ding_miao_ma_zheng_2005, title={Spatial character of the gaseous and particulate state compound correlation of urban atmospheric pollution in winter and summer}, volume={48}, ISSN={["1006-9313"]}, DOI={10.1360/05yd0393}, journal={SCIENCE IN CHINA SERIES D-EARTH SCIENCES}, author={Xu, XD and Shi, XH and Xie, L and Ding, GA and Miao, QJ and Ma, JZ and Zheng, XD}, year={2005}, month={Nov}, pages={64–79} }
 @article{xie_yan_pietrafesa_2005, title={The  effect of Atlantic sea surface temperature dipole mode on hurricanes: Implications for the 2004 Atlantic hurricane season}, volume={32}, number={3}, journal={Geophysical Research Letters}, author={Xie, L. and Yan, T. Z. and Pietrafesa, L.}, year={2005} }
 @article{xie_2005, title={The effect of Atlantic sea surface temperature dipole mode on hurricanes: Implications for the 2004 Atlantic hurricane season}, volume={32}, ISSN={0094-8276}, url={http://dx.doi.org/10.1029/2004GL021702}, DOI={10.1029/2004GL021702}, abstractNote={Results from this study indicate that the dipole mode of tropical Atlantic Ocean sea surface temperature (SST) anomalies is correlated with the overall activity of hurricanes as well as with the annual hurricane landfall frequency along the southeast coast of the United States. The tropical Atlantic SST dipole mode could affect hurricanes in at least three ways: 1) modulating the weather in West Saharan Africa; 2) influencing the local SST and hence the atmosphere‐ocean environment in the hurricane main development region; 3) coupling with the tropical and subtropical atmospheric circulation that controls the steering of hurricanes. The warm tropical North Atlantic and cool tropical South Atlantic waters are likely one of the main causes for Florida's hurricane havoc in 2004.}, number={3}, journal={Geophysical Research Letters}, publisher={American Geophysical Union (AGU)}, author={Xie, Lian}, year={2005} }
 @article{song_semazzi_xie_ogallo_2004, title={A coupled regional climate model for the Lake Victoria basin of East Africa}, volume={24}, ISSN={["1097-0088"]}, DOI={10.1002/joc.983}, abstractNote={Abstract}, number={1}, journal={INTERNATIONAL JOURNAL OF CLIMATOLOGY}, author={Song, Y and Semazzi, FHM and Xie, L and Ogallo, LJ}, year={2004}, month={Jan}, pages={57–75} }
 @article{bao_xie_raman_2004, title={A numerical study of a TOGA-COARE squall-line using a coupled mesoscale atmosphere-ocean model}, volume={21}, ISSN={["1861-9533"]}, DOI={10.1007/BF02916368}, number={5}, journal={ADVANCES IN ATMOSPHERIC SCIENCES}, author={Bao, SW and Xie, L and Raman, S}, year={2004}, month={Sep}, pages={708–716} }
 @article{peng_xie_pietrafesa_2004, title={A numerical study of storm surge and inundation in the Croatan-Albemarle-Pamlico Estuary System}, volume={59}, ISSN={["1096-0015"]}, DOI={10.1016/j.ecss.2003.07.010}, abstractNote={An integrated storm surge and inundation modeling system is used to simulate the storm surge and inundation in the Croatan–Albemarle–Pamlico Estuary System in eastern North Carolina under the influence of 10 hypothetical Category 2 and 3 hurricanes representing typical historical hurricane scenarios in the study region. The integrated storm surge and inundation modeling system is numerically stable in the complex and shallow CAPES environment under hurricane forcing conditions. For an assumed northward or northeastward moving Category 3 hurricane with a translation speed of 25 km/h, the peak storm surge occurs along the western Pamlico Sound and western Albemarle Sound. The most severe flooding as measured by inundation area is in the Pamlico River mouth region where the flooding area reached 500 km2. In general, a more intense or larger hurricane (lower minimum central pressure, MCP or larger radius of maximum wind, RMW) produces higher storm surge and a larger inundation area in the entire region. For the cases considered in this study, the storm surge height and inundation area are more sensitive to MCP than to RMW. Slower translation speed produces higher storm surge, and thus larger inundation area, but the sensitivity of storm surge to storm translation speed can be vastly different for different storms.}, number={1}, journal={ESTUARINE COASTAL AND SHELF SCIENCE}, author={Peng, MC and Xie, L and Pietrafesa, LJ}, year={2004}, month={Jan}, pages={121–137} }
 @article{xie_pietrafesa_peng_2004, title={Incorporation of a mass-conserving inundation scheme into a three dimensional storm surge model}, volume={20}, ISSN={["0749-0208"]}, DOI={10.2112/03-0084r.1}, abstractNote={Abstract The rapid rise and fall of coastal sea level due to tides and storm surge complicates the application of hydrodynamic models that use constant lateral boundaries in the region where sea level change falls within the tidal range or between the negative and positive surge extremes. In order to enable a hydrodynamic model for use in tidal or surge zones, an inundation and drying scheme must be incorporated into the hydrodynamic model. In this study, a mass-conserving inundation (wetting) and draining (drying) scheme is incorporated into a three-dimensional hydrodynamic model (the Princeton Ocean Model, often referred to as POM) for coastal ocean and estuarine systems. This coupled hydrodynamic and inundation modeling system is tested in an idealized lake/estuarine setting. The results show that: 1) incorporation of the inundation/drying scheme into the POM enabled its application in shallow water systems with time-dependent coastal boundaries; 2) the mass conservation constraint used in the inundation and drying scheme eliminates the problem of artificial flooding associated with the imbalance of water mass that is typical of a non-mass-conserving schemes; 3) using vertically-averaged flow as flooding velocity resulted in a reduced flooding area as compared to the cases that use the surface flow as the flooding velocity. This is partly due to the fact that vertically-averaged flow tends to be weaker and directed more parallel to the coastline than the surface flow.}, number={4}, journal={JOURNAL OF COASTAL RESEARCH}, author={Xie, L and Pietrafesa, LJ and Peng, MC}, year={2004}, pages={1209–1223} }
 @article{guan_xie_2004, title={On the linear parameterization of drag coefficient over sea surface}, volume={34}, ISSN={["1520-0485"]}, DOI={10.1175/JPO2664.1}, abstractNote={Abstract}, number={12}, journal={JOURNAL OF PHYSICAL OCEANOGRAPHY}, author={Guan, CL and Xie, L}, year={2004}, month={Dec}, pages={2847–2851} }
 @article{xie_pietrafesa_wu_2003, title={A numerical study of wave-current interaction through surface and bottom stresses: Coastal ocean response to Hurricane Fran of 1996}, volume={108}, ISSN={["2169-9291"]}, DOI={10.1029/2001jc001078}, abstractNote={A three‐dimensional wave‐current coupled modeling system is used to examine the influence of waves on coastal currents and sea level. This coupled modeling system consists of the wave model‐WAM (Cycle 4) and the Princeton Ocean Model (POM). The results from this study show that it is important to incorporate surface wave effects into coastal storm surge and circulation models. Specifically, we find that (1) storm surge models without coupled surface waves generally under estimate not only the peak surge but also the coastal water level drop which can also cause substantial impact on the coastal environment, (2) introducing wave‐induced surface stress effect into storm surge models can significantly improve storm surge prediction, (3) incorporating wave‐induced bottom stress into the coupled wave‐current model further improves storm surge prediction, and (4) calibration of the wave module according to minimum error in significant wave height does not necessarily result in an optimum wave module in a wave‐current coupled system for current and storm surge prediction.}, number={C2}, journal={JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS}, author={Xie, L and Pietrafesa, LJ and Wu, K}, year={2003}, month={Feb} }
 @inbook{pietrafesa_xie_dickey_peng_yan_2003, title={North Carolina State University coastal and estuary storm surge and flood prediction system}, ISBN={1853128341}, booktitle={Ecosystems and Sustainable Development IV}, publisher={Southampton; Boston: WIT Press}, author={Pietrafesa, L. J. and Xie, L. and Dickey, D. A. and Peng, M. and Yan, S.}, editor={E. Tiezzi, C. A. Brebbia and Uso, J. L.Editors}, year={2003}, pages={101–110} }
 @article{manghnani_subrahmanyam_xie_morrison_2003, title={Numerical simulation of seasonal and interannual Indian Ocean upper layer circulation using Miami Isopycnic Coordinate Ocean Model}, volume={108}, number={C7}, journal={Journal of Geophysical Research. Oceans}, author={Manghnani, V. and Subrahmanyam, B. and Xie, L. and Morrison, J. M.}, year={2003} }
 @article{bao_raman_xie_2003, title={Numerical simulation of the response of the ocean surface layer to precipitation}, volume={160}, ISSN={["0033-4553"]}, DOI={10.1007/s00024-003-2402-4}, number={12}, journal={PURE AND APPLIED GEOPHYSICS}, author={Bao, SW and Raman, S and Xie, L}, year={2003}, month={Dec}, pages={2419–2446} }
 @article{bright_xie_pietrafesa_2002, title={Evidence of the Gulf Stream's influence on tropical cyclone intensity}, volume={29}, ISSN={["0094-8276"]}, DOI={10.1029/2002gl014920}, abstractNote={Historical storm data and satellite imagery are analyzed to determine the intensity changes and storm‐related characteristics of 53 coastal and landfalling tropical cyclones (TCs) from Florida to North Carolina that passed over the Gulf Stream (GS) during the period 1944–2000. It appears that less intense storms (Category 2 or weaker), as well as those occurring earlier in the Atlantic hurricane season, are more likely to be strengthened by the GS. In addition, 81% of the Category 2 or weaker storms that intensified based on both maximum wind speed (MWS) and minimum central pressure (MCP) had tracks approximately parallel to the GS, while 3 of the 5 major (Category 3–5) hurricanes that intensified based on both MWS and MCP tracked perpendicular to the GS. The presence of an upstream mid‐latitude trough could have contributed to the intensification of the weaker TCs by steering them along the GS.}, number={16}, journal={GEOPHYSICAL RESEARCH LETTERS}, author={Bright, RJ and Xie, L and Pietrafesa, LJ}, year={2002}, month={Aug} }
 @article{manghnani_morrison_xie_subrahmanyam_2002, title={Heat transports in the Indian Ocean estimated from TOPEX/POSEIDON altimetry and model simulations}, volume={49}, ISSN={["1879-0100"]}, DOI={10.1016/S0967-0645(01)00153-9}, abstractNote={Estimates of the heat budget of the Indian Ocean computed using TOPEX/Poseidon (T/P) sea-level anomalies and the Miami Isopycnal Coordinate Ocean Model are compared to study the redistribution of heat in the Indian Ocean. In particular, the horizontal heat transport and heat storage are used because they typically change on time scales of months or years or longer, and are therefore a predictable element of the climate system. The results show that T/P-derived heat storage is weaker than that derived from the model but has similar spatial structure and temporal evolution. Complex principal component analysis shows that there are two main modes of heat content redistribution in the Indian Ocean. The most dominant mode has an annual signal peaking in the boreal summer, and depicts the response to strong southwest monsoon winds. This involves offshore propagation of heat in the northern Indian Ocean and southward propagation of heat across the equator. The other main mode of heat content redistribution in the Indian Ocean results from westward propagating equatorial Rossby waves. This process is prominent in the boreal fall to spring, and represents the dynamic readjustment of the Indian Ocean to near-equatorial wind forcing. This mode indirectly relates to the dipole mode index in the Indian Ocean. The minima of this time series coincide with the occurrence of the anomalous dipole structure in the equatorial Indian Ocean.}, number={7-8}, journal={DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY}, author={Manghnani, V and Morrison, JM and Xie, LA and Subrahmanyam, B}, year={2002}, pages={1459–1480} }
 @article{xie_pietrafesa_wu_2002, title={Interannual and decadal variability of landfalling tropical cyclones in the southeast coastal states of the United States}, volume={19}, ISSN={["1861-9533"]}, DOI={10.1007/s00376-002-0007-y}, number={4}, journal={ADVANCES IN ATMOSPHERIC SCIENCES}, author={Xie, L and Pietrafesa, LJ and Wu, KJ}, year={2002}, pages={677–686} }
 @article{pietrafesa_flagg_xie_weatherly_morrison_2002, title={The winter/spring 1996 OMP current, meteorological, sea state and coastal sea level fields}, volume={49}, ISSN={["0967-0645"]}, DOI={10.1016/S0967-0645(02)00166-2}, abstractNote={The time series of atmospheric winds, coastal sea level, surface gravity waves, currents, water temperature, and salinity for the period February–May 1996 across the OMP moored array defined a well-organized physical oceanographic system. The M2 tide, a frictionally modified Poincare wave, was manifested as a clockwise-rotating, elliptically polarized wave, with predominantly cross-shelf orientation of the ellipse, and an axis ratio of ∼0.6 in upper layer waters and in offshore waters. However, bottom friction compressed and rotated the tidal ellipses in shallow and near-bottom waters. Elliptically polarized, clockwise-rotating motions were evident at near-inertial (∼20 h) and diurnal (∼24 h) periods. The wind field was dominated by 2–14 day events centered about 4–8 days. Due to the location and track of mesoscale atmospheric events, the wind field over the southern portion of the array was far more energetic than over the northern portion. The winds prior to 17 April had higher variances than after 17 April. Sub-diurnal frequency currents were dynamically responsive to the wind field at all locations and were stronger in the southern portion of the array. The shelf-wide, southward drift of Middle Atlantic Bight waters contributed to the weekly to monthly scales of motion. Shelf-wide, the record length means were generally southward, with an offshore component in near-bottom waters. However, a significant finding was that near the 21 m isobath on the north line of moorings, just south of the mouth of Chesapeake Bay, the mean flow was into the Bay, providing a means for the import of marine sediment into the estuary. In the southeastern-most corner of the array, north of Diamond Shoals in 36 m of water, the flows were persistently directed offshore. Following southward wind events, an inability to propagate Kelvin waves northward along the coast traps a buildup of water against Diamond Shoals such that the only way for it to relax is through a geostrophically balanced offshore transport of shelf waters. The Chesapeake Bay Plume and Middle Atlantic Bight Waters often breached Diamond Shoals and invaded the South Atlantic Bight during the passage of movement northward with southward-directed wind events, particularly extra-tropical cyclones. Following the mid-April transition to persistent northward winds, Carolina Capes Water moved northward across Diamond Shoals and induced a transition from well-mixed wintertime to vertically stratified summertime hydrographic conditions.}, number={20}, journal={DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY}, author={Pietrafesa, LJ and Flagg, CN and Xie, L and Weatherly, GL and Morrison, JM}, year={2002}, pages={4331–4354} }
 @article{xie_wu_pietrafesa_zhang_2001, title={A numerical study of wave-current interaction through surface and bottom stresses: Wind-driven circulation in the South Atlantic Bight under uniform winds}, volume={106}, ISSN={["2169-9291"]}, DOI={10.1029/2000JC000292}, abstractNote={The influences of surface waves on ocean currents in the coastal waters of the South Atlantic Bight are investigated by using a coupled wave‐current modeling system. The ocean circulation model employed is the three‐dimensional Princeton Ocean Model (POM), and the wave model invoked is an improved third‐generation wave model (WAM). The coupling procedure between the POM and the WAM and the simulated coastal ocean circulation driven by uniform surface winds are presented. The simulated results show that wind waves can significantly affect coastal ocean currents not only through an enhancement of wind stress but also through a modification of bottom stress. Wave‐induced wind stress increases the magnitude of currents both at the surface and near the seabed. On the other hand, wave‐induced bottom stress weakens the currents both at the sea surface and near the seabed. Therefore the net effect of surface wind waves on currents depends on the relative importance of current modulations by wave‐induced wind stress and bottom stress. The results further indicate that at a fixed location, the relative importance of wave‐induced surface and bottom shear stresses in coastal ocean circulation depends on the surface wind field. For the constant wind cases considered in this study, the effect of wave‐induced bottom stress is more significant in along‐shore wind conditions than in cross‐shore wind conditions.}, number={C8}, journal={JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS}, author={Xie, LA and Wu, KJ and Pietrafesa, L and Zhang, C}, year={2001}, month={Aug}, pages={16841–16855} }
 @article{xie_eggleston_1999, title={Computer simulations of wind-induced estuarine circulation patterns and estuary-shelf exchange processes: The potential role of wind forcing on larval transport}, volume={49}, ISSN={["0272-7714"]}, DOI={10.1006/ecss.1999.0498}, abstractNote={Wind and density (salinity) driven circulation patterns in the Croatan-Albemarle-Pamlico Estuarine System (CAPES), North Carolina and its interaction with shelf waters via inlets were investigated using the three-dimensional Princeton Ocean Model (POM). This study examines the sensitivity of three-dimensional flow within the CAPES and the exchange of water mass between the CAPES and continental shelf to eight different wind directions. The results indicate that stochastic wind forcing could interact with the topography of coastline and the geographic locations of inlet sources of larvae, to produce spatiotemporal variation in larval supply to potential estuarine nursery habitats. Larval transport between Pamlico, Croatan and Albemarle Sounds, and exchange between estuary and shelf can have horizontal and vertical variations. Thus, three dimensional models coupled with information on larval vertical migration behavior, are required to explain inshore migration and settlement patterns of estuarine-dependent finfish and crustaceans.}, number={2}, journal={ESTUARINE COASTAL AND SHELF SCIENCE}, author={Xie, L and Eggleston, DB}, year={1999}, month={Aug}, pages={221–234} }
 @article{xie_pietrafesa_zhang_1999, title={Subinertial response of the Gulf Stream system to Hurricane Fran of 1996}, volume={26}, ISSN={["0094-8276"]}, DOI={10.1029/1999GL002359}, abstractNote={The evidence of subinertial‐frequency (with periods from 2 days to 2 weeks) oceanic response to Hurricane Fran of 1996 is documented. Hurricane Fran traveled northward across the Gulf Stream and then over a cool‐core trough, known as the Charleston Trough, due east of Charleston, SC and in the lee of the Charleston Bump during the period 4–5 September, 1996. During the passage of the storm, the trough closed into a gyre to form an intense cool‐core cyclonic eddy. This cool‐core eddy had an initial size of approximately 130 km by 170 km and drifted northeastward along the Gulf Stream front at a speed of 13 to 15 km/day as a subinertial baroclinic wave. Superimposed on this subinertial‐frequency wave were near‐inertial frequency, internal inertia‐gravity waves formed in the stratified mixed‐layer base after the passage of the storm. The results from a three‐dimensional numerical ocean model confirm the existence of both near‐inertial and subinertial‐frequency waves in the Gulf Stream system during and after the passage of Hurricane Fran. Model results also showed that hurricane‐forced oceanic response can modify Gulf Stream variability at both near‐inertial and subinertial frequencies.}, number={23}, journal={GEOPHYSICAL RESEARCH LETTERS}, author={Xie, L and Pietrafesa, LJ and Zhang, C}, year={1999}, month={Dec}, pages={3457–3460} }
 @article{xie_pietrafesa_1999, title={Systemwide modeling of wind and density driven circulation in Croatan-Albemarle-Pamlico Estuary System part I: Model configuration and testing}, volume={15}, number={4}, journal={Journal of Coastal Research}, author={Xie, L. and Pietrafesa, L. J.}, year={1999}, pages={1163–1177} }
 @article{xie_pietrafesa_bohm_zhang_li_1998, title={Evidence and mechanism of Hurricane Fran induced cooling in the Charleston trough}, volume={25}, ISSN={["0094-8276"]}, DOI={10.1029/98GL00180}, abstractNote={Evidence of enhanced sea surface cooling during and following the passage of Hurricane Fran in September 1996 over an oceanic depression located on the ocean margin offshore of Charleston, South Carolina (referred to as the Charleston Trough), [Pietrafesa, 1983] is documented. Approximately 4C° of sea surface temperature (SST) reduction within the Charleston Trough following the passage of Hurricane Fran was estimated based on SST imagery from Advanced Very High Resolution Radiometer (AVHRR) on the NOAA‐14 polar orbiting satellite. Simulations using a three‐dimensional coastal ocean model indicate that the largest SST reduction occurred within the Charleston Trough. This SST reduction can be explained by oceanic mixing due to storm‐induced internal inertia‐gravity waves.}, number={6}, journal={GEOPHYSICAL RESEARCH LETTERS}, author={Xie, L and Pietrafesa, LJ and Bohm, E and Zhang, C and Li, X}, year={1998}, month={Mar}, pages={769–772} }
 @article{liu_morrison_xie_1997, title={A numerical study of the response of Tropical Pacific SST to atmospheric forcing}, volume={45}, number={4}, journal={Mausam}, author={Liu, X. and Morrison, J.M. and Xie, L.}, year={1997}, pages={657–668} }
 @article{xie_pietrafesa_raman_1997, title={Interaction between surface wind and ocean circulation in the Carolina Capes in a coupled low-order model}, volume={17}, ISSN={["0278-4343"]}, DOI={10.1016/S0278-4343(97)00024-1}, abstractNote={Abstract Interactions between surface winds and ocean currents over an east-coast continental shelf are studied using a simple mathematical model. The model physics includes cross-shelf advection of sea surface temperature (SST) by Ekman drift, upwelling due to Ekman transport divergence, differential heating of the low-level atmosphere by a cross-shelf SST gradient, and the Coriolis effect. Additionally, the effects of diabatic cooling of surface waters due to air-sea heat exchange and of the vertical density stratification on the thickness of the upper ocean Ekman layer are considered. The model results are qualitatively consistent with observed wind-driven coastal ocean circulation and surface wind signatures induced by SST. This simple model also demonstrates that two-way air-sea interaction plays a significant role in the subtidal frequency variability of coastal ocean circulation and mesoscale variability of surface wind fields over coastal waters.}, number={12}, journal={CONTINENTAL SHELF RESEARCH}, author={Xie, L and Pietrafesa, LJ and Raman, S}, year={1997}, month={Oct}, pages={1483–1511} }
 @article{pietrafesa_xie_morrison_janowitz_pelissier_keeter_neuherz_1997, title={Numerical modelling and computer visualization of the storm surge in and around the Croatan-Albemarle-Pamlico Estuary system produced by Hurricane Emily of August 1993}, volume={48}, number={4}, journal={Mausam}, author={Pietrafesa, L. J. and Xie, L. and Morrison, J. and Janowitz, G. S. and Pelissier, J. and Keeter, K. and Neuherz, R. A.}, year={1997}, pages={567–578} }