TY - JOUR TI - A simple error estimation method for linear-regression-based thermal sharpening techniques with the consideration of scale difference AU - Chen, Xuehong AU - Li, Wentao AU - Chen, Jin AU - Zhan, Wenfeng AU - Rao, Yuhan T2 - Geo-spatial Information Science AB - Thermal remote sensing imagery is helpful for land cover classification and related analysis. Unfortunately, the spatial resolution of thermal infrared (TIR) band is generally coarser than that of visual near-infrared band, which limits its more precise applications. Various thermal sharpening (TSP) techniques have been developed for improving the spatial resolution of the imagery of TIR band or land surface temperature (LST). However, there is no research on the theoretical estimation of TSP error till now, which implies that the error in sharpened LST imagery is unknown and the further analysis might be not reliable. In this paper, an error estimation method based on classical linear regression theory for the linear-regression-based TSP techniques was firstly introduced. However, the scale difference between the coarse resolution and fine resolution is not considered in this method. Therefore, we further developed an improved error estimation method with the consideration of the scale difference, which employs a novel term named equivalent random sample size to reflect the scale difference. A simulation study of modified TsHARP (a typical TSP technique) shows that the improved method estimated the TSP error more accurately than classical regression theory. Especially, the phenomena that TSP error increases with the increasing resolution gap between the initial and target resolutions can be successfully predicted by the proposed method. DA - 2014/1/2/ PY - 2014/1/2/ DO - 10.1080/10095020.2014.889546 VL - 17 IS - 1 SP - 54-59 KW - thermal sharpening KW - error estimation KW - linear regression KW - equivalent random sample size ER - TY - JOUR TI - Earlier vegetation green-up has reduced spring dust storms AU - Fan, B. AU - Guo, L. AU - Li, N. AU - Chen, J. AU - Lin, H. AU - Zhang, X. AU - Shen, M. AU - Rao, Y. AU - Wang, C. AU - Ma, L. T2 - Scientific Reports AB - The observed decline of spring dust storms in Northeast Asia since the 1950s has been attributed to surface wind stilling. However, spring vegetation growth could also restrain dust storms through accumulating aboveground biomass and increasing surface roughness. To investigate the impacts of vegetation spring growth on dust storms, we examine the relationships between recorded spring dust storm outbreaks and satellite-derived vegetation green-up date in Inner Mongolia, Northern China from 1982 to 2008. We find a significant dampening effect of advanced vegetation growth on spring dust storms (r = 0.49, p = 0.01), with a one-day earlier green-up date corresponding to a decrease in annual spring dust storm outbreaks by 3%. Moreover, the higher correlation (r = 0.55, p < 0.01) between green-up date and dust storm outbreak ratio (the ratio of dust storm outbreaks to times of strong wind events) indicates that such effect is independent of changes in surface wind. Spatially, a negative correlation is detected between areas with advanced green-up dates and regional annual spring dust storms (r = -0.49, p = 0.01). This new insight is valuable for understanding dust storms dynamics under the changing climate. Our findings suggest that dust storms in Inner Mongolia will be further mitigated by the projected earlier vegetation green-up in the warming world. DA - 2014/// PY - 2014/// DO - 10.1038/srep06749 VL - 4 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84947281985&partnerID=MN8TOARS ER - TY - JOUR TI - A combination of TsHARP and thin plate spline interpolation for spatial sharpening of thermal imagery AU - Chen, X. AU - Li, W. AU - Chen, J. AU - Rao, Y. AU - Yamaguchi, Y. T2 - Remote Sensing AB - There have been many studies and much attention paid to spatial sharpening for thermal imagery. Among them, TsHARP, based on the good correlation between vegetation index and land surface temperature (LST), is regarded as a standard technique because of its operational simplicity and effectiveness. However, as LST is affected by other factors (e.g., soil moisture) in the areas with low vegetation cover, these areas cannot be well sharpened by TsHARP. Thin plate spline (TPS) is another popular downscaling technique for surface data. It has been shown to be accurate and robust for different datasets; however, it has not yet been attempted in thermal sharpening. This paper proposes to combine the TsHARP and TPS methods to enhance the advantages of each. The spatially explicit errors of these two methods were firstly estimated in theory, and then the results of TPS and TsHARP were combined with the estimation of their errors. The experiments performed across various landscapes and data showed that the proposed combined method performs more robustly and accurately than TsHARP. DA - 2014/// PY - 2014/// DO - 10.3390/rs6042845 VL - 6 IS - 4 SP - 2845-2863 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84898077645&partnerID=MN8TOARS KW - thermal sharpening KW - land surface temperature KW - TsHARP KW - thin plate spline KW - error estimation ER - TY - TI - Introduction to Scientific Data Stewardship Maturity Matrix AU - Peng, Ge DA - 2014/10/17/ PY - 2014/10/17/ DO - 10.6084/m9.figshare.1150243 UR - https://figshare.com/articles/Scientific_Data_Stewardship_Maturity_Matrix/1150243 ER - TY - CONF TI - A stewardship maturity matrix for assessing the state of environmental data quality and usability AU - Peng, G. AU - Privette, J.L. C2 - 2014/2// C3 - 10th Annual Symposium on New Generation Operational Environmental Satellite Systems DA - 2014/2// SP - 2– 6, ER - TY - CONF TI - An End-to-End Framework for Probabilistic Uncertainty Characterization of Climate Satellite Data and Products AU - Peng, G. AU - Cecil, L.D. AU - Cramer, B. C2 - 2014/2// C3 - 10th Annual Symposium on New Generation Operational Environmental Satellite Systems DA - 2014/2// SP - 2– 6, ER - TY - JOUR TI - Directional bias of TAO daily buoy wind vectors in the central equatorial Pacific Ocean from November 2008 to January 2010 T2 - Data Science Journal AB - The CODATA Data Science Journal is a peer-reviewed, open access, electronic journal, publishing papers on the management, dissemination, use and reuse of research data and databases across all research domains, including science, technology, the humanities and the arts. The scope of the journal includes descriptions of data systems, their implementations and their publication, applications, infrastructures, software, legal, reproducibility and transparency issues, the availability and usability of complex datasets, and with a particular focus on the principles, policies and practices for open data.All data is in scope, whether born digital or converted from other sources. DA - 2014/7// PY - 2014/7// DO - 10.2481/dsj.14-019 UR - https://www.jstage.jst.go.jp/article/dsj/13/0/13_14-019/_article ER - TY - JOUR TI - Verification of a new NOAA/NSIDC passive microwave sea-ice concentration climate record AU - Meier, Walter N. AU - Peng, Ge AU - Scott, Donna J. AU - Savoie, Matt H. T2 - POLAR RESEARCH AB - A new satellite-based passive microwave sea-ice concentration product developed for the National Oceanic and Atmospheric Administration (NOAA) Climate Data Record (CDR) programme is evaluated via comparison with other passive microwave-derived estimates. The new product leverages two well-established concentration algorithms, known as the NASA Team and Bootstrap, both developed at and produced by the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC). The sea-ice estimates compare well with similar GSFC products while also fulfilling all NOAA CDR initial operation capability (IOC) requirements, including (1) self-describing file format, (2) ISO 19115-2 compliant collection-level metadata, (3) Climate and Forecast (CF) compliant file-level metadata, (4) grid-cell level metadata (data quality fields), (5) fully automated and reproducible processing and (6) open online access to full documentation with version control, including source code and an algorithm theoretical basic document. The primary limitations of the GSFC products are lack of metadata and use of untracked manual corrections to the output fields. Smaller differences occur from minor variations in processing methods by the National Snow and Ice Data Center (for the CDR fields) and NASA (for the GSFC fields). The CDR concentrations do have some differences from the constituent GSFC concentrations, but trends and variability are not substantially different.Keywords: Sea ice; Arctic and Antarctic oceans; climate data record; evaluation; passive microwave remote sensing.(Published: 22 December 2014)Citation: Polar Research 2014, 33, 21004, http://dx.doi.org/10.3402/polar.v33.21004 DA - 2014/// PY - 2014/// DO - 10.3402/polar.v33.21004 VL - 33 SP - SN - 1751-8369 UR - http://www.polarresearch.net/index.php/polar/article/view/21004 KW - Sea ice KW - Arctic and Antarctic oceans KW - climate data record KW - evaluation KW - passive microwave remote sensing ER - TY - JOUR TI - The Impact of Raindrop Collisional Processes on the Polarimetric Radar Variables AU - Kumjian, Matthew R. AU - Prat, Olivier P. T2 - JOURNAL OF THE ATMOSPHERIC SCIENCES AB - Abstract The impact of the collisional warm-rain microphysical processes on the polarimetric radar variables is quantified using a coupled microphysics–electromagnetic scattering model. A one-dimensional bin-microphysical rain shaft model that resolves explicitly the evolution of the drop size distribution (DSD) under the influence of collisional coalescence and breakup, drop settling, and aerodynamic breakup is coupled with electromagnetic scattering calculations that simulate vertical profiles of the polarimetric radar variables: reflectivity factor at horizontal polarization ZH, differential reflectivity ZDR, and specific differential phase KDP. The polarimetric radar fingerprint of each individual microphysical process is quantified as a function of the shape of the initial DSD and for different values of nominal rainfall rate. Results indicate that individual microphysical processes (collisional processes, evaporation) display a distinctive signature and evolve within specific areas of ZH–ZDR and ZDR–KDP space. Furthermore, a comparison of the resulting simulated vertical profiles of the polarimetric variables with radar and disdrometer observations suggests that bin-microphysical parameterizations of drop breakup most frequently used are overly aggressive for the largest rainfall rates, resulting in very “tropical” DSDs heavily skewed toward smaller drops. DA - 2014/8// PY - 2014/8// DO - 10.1175/jas-d-13-0357.1 VL - 71 IS - 8 SP - 3052-3067 SN - 1520-0469 ER - TY - JOUR TI - A Numerical Investigation of the Precipitation over Lake Victoria Basin Using a Coupled Atmosphere-Lake Limited-Area Model AU - Sun, Xia AU - Xie, Lian AU - Semazzi, Fredrick H. M. AU - Liu, Bin T2 - ADVANCES IN METEOROLOGY AB - 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. DA - 2014/// PY - 2014/// DO - 10.1155/2014/960924 VL - 2014 SP - SN - 1687-9317 ER - TY - JOUR TI - A 1/4 degrees-spatial-resolution daily sea surface temperature climatology based on a blended satellite and in situ analysis AU - Banzon, V. F. AU - Reynolds, R. W. AU - Stokes, D. AU - Xue, Y. T2 - Journal of Climate DA - 2014/// PY - 2014/// VL - 27 IS - 21 SP - 8221-8228 ER - TY - JOUR TI - The Impact of Best Track Discrepancies on Global Tropical Cyclone Climatologies using IBTrACS AU - Schreck, Carl J., III AU - Knapp, Kenneth R. AU - Kossin, James P. T2 - MONTHLY WEATHER REVIEW AB - Abstract Using the International Best Track Archive for Climate Stewardship (IBTrACS), the climatology of tropical cyclones is compared between two global best track datasets: 1) the World Meteorological Organization (WMO) subset of IBTrACS (IBTrACS-WMO) and 2) a combination of data from the National Hurricane Center and the Joint Typhoon Warning Center (NHC+JTWC). Comparing the climatologies between IBTrACS-WMO and NHC+JTWC highlights some of the heterogeneities inherent in these datasets for the period of global satellite coverage 1981–2010. The results demonstrate the sensitivity of these climatologies to the choice of best track dataset. Previous studies have examined best track heterogeneities in individual regions, usually the North Atlantic and west Pacific. This study puts those regional issues into their global context. The differences between NHC+JTWC and IBTrACS-WMO are greatest in the west Pacific, where the strongest storms are substantially weaker in IBTrACS-WMO. These disparities strongly affect the global measures of tropical cyclone activity because 30% of the world’s tropical cyclones form in the west Pacific. Because JTWC employs similar procedures throughout most of the globe, the comparisons in this study highlight differences between WMO agencies. For example, NHC+JTWC has more 96-kt (~49 m s−1) storms than IBTrACS-WMO in the west Pacific but fewer in the Australian region. This discrepancy probably points to differing operational procedures between the WMO agencies in the two regions. Without better documentation of historical analysis procedures, the only way to remedy these heterogeneities will be through systematic reanalysis. DA - 2014/10// PY - 2014/10// DO - 10.1175/mwr-d-14-00021.1 VL - 142 IS - 10 SP - 3881-3899 SN - 1520-0493 ER - TY - JOUR TI - Rain use efficiency as affected by climate warming and biofuel harvest: results from a 12-year field experiment AU - Yan, L. M. AU - Luo, Y. Q. AU - Sherry, R. A. AU - Bell, J. E. AU - Zhou, X. H. AU - Xia, J. Y. T2 - Global Change Biology Bioenergy DA - 2014/// PY - 2014/// VL - 6 IS - 5 SP - 556-565 ER - TY - JOUR TI - Characteristics of annual, seasonal, and diurnal precipitation in the Southeastern United States derived from long-term remotely sensed data AU - Prat, Olivier P. AU - Nelson, Brian R. T2 - ATMOSPHERIC RESEARCH AB - The objective of this paper is to investigate long-term inter-annual, seasonal, and diurnal rainfall characteristics in the Southeastern United States. In order to capture precipitation features at high resolution, we use precipitation estimates from the Tropical Rainfall Measuring Mission (TRMM); the TRMM Precipitation Radar (TPR 2A25: 0.05° × 0.05°/daily) and the TRMM Multi-satellite Precipitation Analysis (TMPA 3B42: 0.25° × 0.25°/3-h) datasets to create a 13-year rainfall climatology. The higher resolution climatology (2A25) displays a greater ability to capture more localized landform precipitation features when compared with 3B42. On an annual basis, the Southeastern US is characterized by a succession of cold and warm precipitation regimes. The cold season is characterized by higher rain intensity West of 82°W (roughly Atlanta, GA) and the warm season is characterized by higher rain intensity over the coastal areas. The cold/warm rainfall regime duality is modulated by local topographic characteristics that prevail along a W–E direction. During the cold season, the diurnal cycle of precipitation is characterized by a quasi-constant repartition of rain events throughout the day and an absence of land/ocean contrast. On the contrary for summertime there is a strong land/ocean signature with a predominance of late morning/early afternoon (12:00–15:00LST) rainfall over ocean and afternoon/early evening (15:00–18:00LST) precipitation events over land that account for more than 25% of the daily events along the coasts. Differences are observed for the Florida peninsula, where the diurnal cycle displays an afternoon maximum of variable intensity due to sea breeze effects regardless of the season. DA - 2014/7/1/ PY - 2014/7/1/ DO - 10.1016/j.atmosres.2013.07.022 VL - 144 SP - 4-20 SN - 1873-2895 KW - Precipitation KW - Diurnal cycle KW - Remote sensing KW - Southeastern United States ER -