@article{nunalee_horvath_basu_2015, title={High-resolution numerical modeling of mesoscale island wakes and sensitivity to static topographic relief data}, volume={8}, ISSN={["1991-9603"]}, DOI={10.5194/gmd-8-2645-2015}, abstractNote={Abstract. Recent decades have witnessed a drastic increase in the fidelity of numerical weather prediction (NWP) modeling. Currently, both research-grade and operational NWP models regularly perform simulations with horizontal grid spacings as fine as 1 km. This migration towards higher resolution potentially improves NWP model solutions by increasing the resolvability of mesoscale processes and reducing dependency on empirical physics parameterizations. However, at the same time, the accuracy of high-resolution simulations, particularly in the atmospheric boundary layer (ABL), is also sensitive to orographic forcing which can have significant variability on the same spatial scale as, or smaller than, NWP model grids. Despite this sensitivity, many high-resolution atmospheric simulations do not consider uncertainty with respect to selection of static terrain height data set. In this paper, we use the Weather Research and Forecasting (WRF) model to simulate realistic cases of lower tropospheric flow over and downstream of mountainous islands using the default global 30 s United States Geographic Survey terrain height data set (GTOPO30), the Shuttle Radar Topography Mission (SRTM), and the Global Multi-resolution Terrain Elevation Data set (GMTED2010) terrain height data sets. While the differences between the SRTM-based and GMTED2010-based simulations are extremely small, the GTOPO30-based simulations differ significantly. Our results demonstrate cases where the differences between the source terrain data sets are significant enough to produce entirely different orographic wake mechanics, such as vortex shedding vs. no vortex shedding. These results are also compared to MODIS visible satellite imagery and ASCAT near-surface wind retrievals. Collectively, these results highlight the importance of utilizing accurate static orographic boundary conditions when running high-resolution mesoscale models.
                    }, number={8}, journal={GEOSCIENTIFIC MODEL DEVELOPMENT}, author={Nunalee, C. G. and Horvath, A. and Basu, S.}, year={2015}, pages={2645–2653} }
 @article{he_nunalee_basu_minet_vorontsov_fiorino_2015, title={Influence of heterogeneous refractivity on optical wave propagation in coastal environments}, volume={127}, ISSN={["1436-5065"]}, DOI={10.1007/s00703-015-0391-3}, number={6}, journal={METEOROLOGY AND ATMOSPHERIC PHYSICS}, author={He, Ping and Nunalee, Christopher G. and Basu, Sukanta and Minet, Jean and Vorontsov, Mikhail A. and Fiorino, Steven T.}, year={2015}, month={Dec}, pages={685–699} }
 @article{nunalee_he_basu_minet_vorontsov_2015, title={Mapping optical ray trajectories through island wake vortices}, volume={127}, number={3}, journal={Meteorology and Atmospheric Physics}, author={Nunalee, C. G. and He, P. and Basu, S. and Minet, J. and Vorontsov, M. A.}, year={2015}, pages={355–368} }
 @article{he_nunalee_basu_vorontsov_fiorino_2014, title={Current Status and Challenges in Optical Turbulence Simulations in Various Layers of the Earth's Atmosphere}, volume={9224}, ISSN={["1996-756X"]}, DOI={10.1117/12.2063023}, abstractNote={In this study, we present a brief review on the existing approaches for optical turbulence estimation in various layers of the Earth’s atmosphere. The advantages and disadvantages of these approaches are also discussed. An alternative approach, based on mesoscale modeling with parameterized turbulence, is proposed and tested for the simulation of refractive index structure parameter (C2n ) in the atmospheric boundary layer. The impacts of a few atmospheric flow phenomena (e.g., low-level jets, island wake vortices, gravity waves) on optical turbulence are discussed. Consideration of diverse geographic settings (e.g., flat terrain, coastal region, ocean islands) makes this study distinct.}, journal={LASER COMMUNICATION AND PROPAGATION THROUGH THE ATMOSPHERE AND OCEANS III}, author={He, Ping and Nunalee, Christopher G. and Basu, Sukanta and Vorontsov, Mikhail A. and Fiorino, Steven T.}, year={2014} }
 @article{nunalee_kosovic_bieringer_2014, title={Eulerian dispersion modeling with WRF-LES of plume impingement in neutrally and stably stratified turbulent boundary layers}, volume={99}, journal={Atmospheric Environment}, author={Nunalee, C. G. and Kosovic, B. and Bieringer, P. E.}, year={2014}, pages={571–581} }
 @article{nunalee_he_basu_vorontsov_fiorino_2014, title={Impact of Large-Scale Atmospheric Refractive Structures on Optical Wave Propagation}, volume={9224}, ISSN={["1996-756X"]}, DOI={10.1117/12.2063022}, abstractNote={Conventional techniques used to model optical wave propagation through the Earth’s atmosphere typically as- sume flow fields based on various empirical relationships. Unfortunately, these synthetic refractive index fields do not take into account the influence of transient macroscale and mesoscale (i.e. larger than turbulent microscale) atmospheric phenomena. Nevertheless, a number of atmospheric structures that are characterized by various spatial and temporal scales exist which have the potential to significantly impact refractive index fields, thereby resulting dramatic impacts on optical wave propagation characteristics. In this paper, we analyze a subset of spatio-temporal dynamics found to strongly affect optical waves propagating through these atmospheric struc- tures. Analysis of wave propagation was performed in the geometrical optics approximation using a standard ray tracing technique. Using a numerical weather prediction (NWP) approach, we simulate multiple realistic atmospheric events (e.g., island wakes, low-level jets, etc.), and estimate the associated refractivity fields prior to performing ray tracing simulations. By coupling NWP model output with ray tracing simulations, we demon- strate the ability to quantitatively assess the potential impacts of coherent atmospheric phenomena on optical ray propagation. Our results show a strong impact of spatio-temporal characteristics of the refractive index field on optical ray trajectories. Such correlations validate the effectiveness of NWP models as they offer a more comprehensive representation of atmospheric refractivity fields compared to conventional methods based on the assumption of horizontal homogeneity.}, journal={LASER COMMUNICATION AND PROPAGATION THROUGH THE ATMOSPHERE AND OCEANS III}, author={Nunalee, Christopher G. and He, Ping and Basu, Sukanta and Vorontsov, Mikhail A. and Fiorino, Steven T.}, year={2014} }
 @article{nunalee_basu_2014, title={Mesoscale Modeling of Low-Level Jets over the North Sea}, volume={2}, ISBN={["978-3-642-54695-2"]}, ISSN={["2196-7806"]}, DOI={10.1007/978-3-642-54696-9_29}, abstractNote={Contemporary onshore and offshore wind resource assessment frameworks incorporate diverse multi-scale weather predictionmodels (commonly known as mesoscale models) to dynamically downscale global-scale atmospheric fields to regional-scale (i.e., spatial and temporal resolutions of a few kilometers and a few minutes, respectively). These high resolution mesoscale models aim at depicting the expected wind behavior (e.g., wind shear, wind turning, topographically induced flow accelerations) at a particular location or region. Over the years, numerous model sensitivity and intercomparison studies have investigated the strengths and weaknesses of the models’ parameterizations (including, but not limited to, planetary boundary layer turbulence) in capturing realistic flows over land. In contrast, only a handful of modeling studies have focused on coastal and offshore flows (e.g., coastal fronts, internal boundary layers, land breeze - sea breeze circulations, low level jets); thus, our understanding and predictive capability of these flows remain less than desirable. This impairment, in combination with the recent world-wide surge in offshore wind energy development, provides the rationale for this study. We are currently evaluating the performance of the Weather Research and Forecasting (WRF) model, a new-generation mesoscale model, in simulating some of the aforementioned coastal and offshore flow phenomena. In this paper, we focus on low-level jets and compare the WRF model-simulated results against the observational data from the FINO1 meteorological mast in the North Sea.We also discuss the sensitivities of the WRF model-generated offshore wind fields with respect to several planetary boundary layer turbulence schemes.}, journal={WIND ENERGY - IMPACT OF TURBULENCE}, author={Nunalee, Christopher and Basu, Sukanta}, year={2014}, pages={197–202} }
 @article{nunalee_basu_2014, title={On the periodicity of atmospheric von Karman vortex streets}, volume={14}, ISSN={["1573-1510"]}, DOI={10.1007/s10652-014-9340-9}, number={6}, journal={ENVIRONMENTAL FLUID MECHANICS}, author={Nunalee, Christopher G. and Basu, Sukanta}, year={2014}, month={Dec}, pages={1335–1355} }
 @article{basu_nunalee_he_fiorino_vorontsov_2014, title={Reconstructing the Prevailing Meteorological and Optical Environment during the Time of the Titanic Disaster}, volume={9224}, ISSN={["1996-756X"]}, DOI={10.1117/12.2063195}, abstractNote={In this paper, we reconstruct the meteorological and optical environment during the time of Titanic’s disaster utilizing a state-of-the-art meteorological model, a ray-tracing code, and a unique public-domain dataset called the Twentieth Century Global Reanalysis. With high fidelity, our simulation captured the occurrence of an unusually high Arctic pressure system over the disaster site with calm wind. It also reproduced the movement of a polar cold front through the region bringing a rapid drop in air temperature. The simulated results also suggest that unusual meteorological conditions persisted several hours prior to the Titanic disaster which contributed to super-refraction and intermittent optical turbulence. However, according to the simulations, such anomalous conditions were not present at the time of the collision of Titanic with an iceberg.}, journal={LASER COMMUNICATION AND PROPAGATION THROUGH THE ATMOSPHERE AND OCEANS III}, author={Basu, Sukanta and Nunalee, Christopher G. and He, Ping and Fiorino, Steven T. and Vorontsov, Mikhail A.}, year={2014} }
 @article{nunalee_basu_2014, title={Mesoscale modeling of coastal low-level jets: implications for offshore wind resource estimation}, volume={17}, ISSN={["1099-1824"]}, DOI={10.1002/we.1628}, abstractNote={Detailed and reliable spatiotemporal characterizations of turbine hub height wind fields over coastal and offshore regions are becoming imperative for the global wind energy industry. Contemporary wind resource assessment frameworks incorporate diverse multiscale prognostic models (commonly known as mesoscale models) to dynamically downscale global-scale atmospheric fields to regional-scale (i.e., spatial and temporal resolutions of a few kilometers and a few minutes, respectively). These high-resolution model solutions aim at depicting the expected wind behavior (e.g., wind shear, wind veering and topographically induced flow accelerations) at a particular location. Coastal and offshore regions considered viable for wind power production are also known to possess complex atmospheric flow phenomena (including, but not limited to, coastal low-level jets (LLJs), internal boundary layers and land breeze–sea breeze circulations). Unfortunately, the capabilities of the new-generation mesoscale models in realistically capturing these diverse flow phenomena are not well documented in the literature. To partially fill this knowledge gap, in this paper, we have evaluated the performance of the Weather Research and Forecasting model, a state-of-the-art mesoscale model, in simulating a series of coastal LLJs. Using observational data sources we explore the importance of coastal LLJs for offshore wind resource estimation along with the capacity to which they can be numerically simulated. We observe model solutions to demonstrate strong sensitivities with respect to planetary boundary layer parameterization and initialization conditions. These sensitivities are found to be responsible for variability in AEP estimates by a factor of two. Copyright © 2013 John Wiley & Sons, Ltd.}, number={8}, journal={WIND ENERGY}, author={Nunalee, Christopher G. and Basu, Sukanta}, year={2014}, month={Aug}, pages={1199–1216} }