Role of Surface Energy Exchange for Simulating Wind Turbine Inflow: A Case Study in the Southern Great Plains, USA

Abstract A nocturnal maximum in rainfall and thunderstorm activity over the central Great Plains has been widely documented, but the mechanisms for the development of thunderstorms over that region at night are still not well understood. Elevated convection above a surface frontal boundary is one explanation, but this study shows that many thunderstorms form at night without the presence of an elevated frontal inversion or nearby surface boundary. This study documents convection initiation (CI) events at night over the central Great Plains from 1996 to 2015 during the months of April–July. Storm characteristics such as storm type, linear system orientation, initiation time and location, and others were documented. Once all of the cases were documented, surface data were examined to locate any nearby surface boundaries. The event’s initiation location relative to these boundaries (if a boundary existed) was documented. Two main initiation locations relative to a surface boundary were identified: on a surface boundary and on the cold side of a surface boundary; CI events also occur without any nearby surface boundary. There are many differences among the different nocturnal CI modes. For example, there appear to be two main peaks of initiation time at night: one early at night and one later at night. The later peak is likely due to the events that form without a nearby surface boundary. Finally, a case study of three nocturnal CI events that occurred during the Plains Elevated Convection At Night (PECAN) field project when there was no nearby surface boundary is discussed.

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Coupling between Large-Scale Atmospheric Processes and Mesoscale Land–Atmosphere Interactions in the U.S. Southern Great Plains during Summer. Part I: Case Studies

Journal of Hydrometeorology ◽

10.1175/jhm-396.1 ◽

2004 ◽

Vol 5 (6) ◽

pp. 1223-1246 ◽

Cited By ~ 36

Author(s):

Christopher P. Weaver

Keyword(s):

Great Plains ◽

Large Scale ◽

Deep Convection ◽

Individual Case ◽

Atmospheric Modeling ◽

Surface Fluxes ◽

Southern Great Plains ◽

Atmospheric Processes ◽

Mesoscale Processes

Abstract This paper is Part I of a two-part study that uses high-resolution Regional Atmospheric Modeling System (RAMS) simulations to investigate mesoscale land–atmosphere interactions in the summertime U.S. Southern Great Plains. The focus is on the atmospheric dynamics associated with mesoscale heterogeneity in the underlying surface fluxes: how shifts in meteorological regimes modulate these diurnal, mesoscale processes, and their overall impact at larger scales and over multiple diurnal cycles. Part I examines individual case study time periods drawn from the simulations that illustrate general points about the key land–atmosphere interactions. The main findings are as follows: The mesoscale processes are embedded within a synoptic-scale organization that controls the background meteorological regime at a given location. During the clear, dry days in the simulated months, heterogeneity in the surface fluxes forces strong, lower-tropospheric, mesoscale circulations that exhibit a characteristic dynamical life cycle over diurnal time scales. In general, the background large-scale flow does not affect the overall intensity of these coherent roll structures, though strong large-scale subsidence can sometimes dampen them. In addition, depending on the thermodynamic profile, the strong vertical motions associated with these circulations are sufficient to trigger shallow or even deep convection, with associated clouds and precipitation. Furthermore, surface heterogeneity sufficient to force such circulations can arise even without heterogeneity in preexisting land cover characteristics such as vegetation, for example, solely as a result of spatial variability in rainfall and other atmospheric processes. In Part II the mesoscale land–atmosphere interactions in these case study periods are placed in the larger context of the full, monthlong simulations.

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Assessment of Diurnal Wind Turbine Collision Risk for Grassland Birds on the Southern Great Plains

Journal of Fish and Wildlife Management ◽

10.3996/042015-jfwm-031 ◽

2016 ◽

Vol 7 (1) ◽

pp. 129-140 ◽

Cited By ~ 4

Author(s):

Sarah J. Wulff ◽

Matthew J. Butler ◽

Warren B. Ballard

Keyword(s):

Wind Energy ◽

Wind Turbine ◽

Great Plains ◽

Wind Turbines ◽

Turbine Blades ◽

Bird Species ◽

The United States ◽

Southern Great Plains ◽

Flight Height ◽

Associated Species

Abstract Wind energy is one of the fastest growing renewable energy sources in the United States and has the potential to reduce the use of traditional nonrenewable energy. However, there is concern for potential short- and long-term influences on wildlife populations, such as bird collisions with turbine blades, habitat loss, habitat fragmentation, and habitat avoidance. Bird flight heights are indicative of collision risks, but knowledge of their distributions is limited. Our goal was to examine the diurnal flight heights of bird species to assess which are at greatest risk of collision with wind turbine blades. During October 2008–August 2009, we estimated the flight heights of 66 bird species at a planned wind energy facility on the southern Great Plains. Flight heights were estimated by measuring angle of incline with a clinometer and ground distance with a laser rangefinder. Previous work has been limited to flight height measurements categorized to site-specific rotor swept zone (RSZ) specifications that has resulted in limited applicability to other wind turbine RSZ specifications. Our research is distinctive because it provides more resolution in flight height estimates than those categorized into bins and allows application to wind turbines with different RSZs. We found that the flight heights of six bird species varied among seasons, indicating their risk of collision changed throughout the year. Observations indicated that the average flight heights of 28 bird species were within the potential RSZ (32–124 m above ground level) at our study site and that two species exhibited mean flight heights above the RSZ. Fifteen of those species were wetland-associated species, 7 were raptor or vulture species, and 6 were listed as species of greatest conservation need by Texas Parks and Wildlife Department. We observed 14 bird species (1 vulture, 2 raptors, 7 wetland-associated species, and 4 passerines or other species) with greater than 25% of their observed flight heights within the RSZ. Our results indicate that raptors and wetland-associated species are the avian groups at greatest risk of collision with wind turbines due to their diurnal flight heights. However, the resolution of our data will allow assessment of which bird species are at greatest risk of collision for various wind turbine specifications. This information can help guide site assessment and placement for wind energy facilities across the southern Great Plains and help mitigate potential collision impacts on bird species.

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Modeling Evapotranspiration of Winter Wheat Using Contextual and Pixel-Based Surface Energy Balance Models

Transactions of the ASABE ◽

10.13031/trans.14087 ◽

2021 ◽

Vol 64 (2) ◽

pp. 507-519

Author(s):

Kul Khand ◽

Nishan Bhattarai ◽

Saleh Taghvaeian ◽

Pradeep Wagle ◽

Prasanna H. Gowda ◽

...

Keyword(s):

Energy Balance ◽

Surface Energy ◽

Winter Wheat ◽

Great Plains ◽

Surface Energy Balance ◽

List Type ◽

Landsat Images ◽

Practical Applications ◽

Southern Great Plains ◽

Flux Tower

HighlightsThree contextual-based (CB) and two pixel-based (PB) models were evaluated to estimate ET of rainfed winter wheat.Instantaneous available energy estimation and ET upscaling impacted model performance.The CB models performed better at instantaneous and daily scales compared to the PB models.ET estimation biases increased during low vegetation and drier conditions, especially for the PB models.Abstract. Surface energy balance (SEB) models based on thermal remote sensing data are widely used in research applications to map evapotranspiration (ET) across various landscapes. However, their ability to capture ET from winter wheat remains underexplored, especially in practical applications such as integrated resource management and drought preparedness. Investigating winter wheat ET dynamics is important in agricultural regions such as the Southern Great Plains of the U.S., where winter wheat is extensively cultivated. The goal of this study was to evaluate the performance of five fully automated SEB models, three contextual-based (CB) and two pixel-based (PB), in estimating instantaneous and daily ET of winter wheat by comparing the model results with flux tower observations. The CB models included Surface Energy Balance Algorithm for Land (SEBAL), Mapping Evapotranspiration at high Resolution with Internalized Calibration (METRIC), and Triangular Vegetation Temperature (TVT). The PB models included Surface Energy Balance System (SEBS) and Two-Source Energy Balance (TSEB). Model evaluation during two winter wheat growing seasons (2016-2018) using 28 Landsat images showed that the instantaneous ET estimates from METRIC and TSEB had the smallest (RMSE = 0.14 mm h-1) and largest (RMSE = 0.27 mm h-1) errors, respectively. At the daily scale, SEBAL was the best performing model (RMSE = 1.0 mm d-1), followed by TVT (RMSE = 1.1 mm d-1), METRIC (RMSE = 1.2 mm d-1), SEBS (RMSE = 1.3 mm d-1), and TSEB (RMSE = 1.5 mm d-1). Overall, the CB models provided smaller errors than the PB models. Larger errors in daily ET estimation were observed during low vegetation and drier conditions, especially for the PB models. Keywords: Flux tower, Landsat, Southern Great Plains, Water use.

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The effect of sub-grid variability of soil moisture on the simulation of mesoscale watershed hydrology: A case study from the Southern Great Plains 1997 Hydrology Experiment

Land Surface Hydrology, Meteorology, and Climate: Observations and Modeling - Water Science and Application ◽

10.1029/ws003p0161 ◽

2001 ◽

pp. 161-176 ◽

Cited By ~ 1

Author(s):

Karen I. Mohr ◽

James S. Famiglietti ◽

Aaron Boone

Keyword(s):

Soil Moisture ◽

Great Plains ◽

Watershed Hydrology ◽

Southern Great Plains

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The influence of land cover on surface energy partitioning and evaporative fraction regimes in the U.S. Southern Great Plains

Journal of Geophysical Research Atmospheres ◽

10.1002/2017jd026740 ◽

2017 ◽

Vol 122 (11) ◽

pp. 5793-5807 ◽

Cited By ~ 19

Author(s):

Justin E. Bagley ◽

Lara M. Kueppers ◽

Dave P. Billesbach ◽

Ian N. Williams ◽

Sébastien C. Biraud ◽

...

Keyword(s):

Surface Energy ◽

Land Cover ◽

Great Plains ◽

Energy Partitioning ◽

Evaporative Fraction ◽

Southern Great Plains ◽

The U.S

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Prospects for Advancing Drought Understanding, Monitoring, and Prediction

Journal of Hydrometeorology ◽

10.1175/jhm-d-14-0164.1 ◽

2015 ◽

Vol 16 (4) ◽

pp. 1636-1657 ◽

Cited By ~ 44

Author(s):

Eric F. Wood ◽

Siegfried D. Schubert ◽

Andrew W. Wood ◽

Christa D. Peters-Lidard ◽

Kingtse C. Mo ◽

...

Keyword(s):

Great Plains ◽

North American ◽

Land Surface ◽

Task Force ◽

Atmospheric Variability ◽

Southern Great Plains ◽

The North ◽

Drought Prediction ◽

Seasonal Model

Abstract This paper summarizes and synthesizes the research carried out under the NOAA Drought Task Force (DTF) and submitted in this special collection. The DTF is organized and supported by NOAA’s Climate Program Office with the National Integrated Drought Information System (NIDIS) and involves scientists from across NOAA, academia, and other agencies. The synthesis includes an assessment of successes and remaining challenges in monitoring and prediction capabilities, as well as a perspective of the current understanding of North American drought and key research gaps. Results from the DTF papers indicate that key successes for drought monitoring include the application of modern land surface hydrological models that can be used for objective drought analysis, including extended retrospective forcing datasets to support hydrologic reanalyses, and the expansion of near-real-time satellite-based monitoring and analyses, particularly those describing vegetation and evapotranspiration. In the area of drought prediction, successes highlighted in the papers include the development of the North American Multimodel Ensemble (NMME) suite of seasonal model forecasts, an established basis for the importance of La Niña in drought events over the southern Great Plains, and an appreciation of the role of internal atmospheric variability related to drought events. Despite such progress, there are still important limitations in our ability to predict various aspects of drought, including onset, duration, severity, and recovery. Critical challenges include (i) the development of objective, science-based integration approaches for merging multiple information sources; (ii) long, consistent hydrometeorological records to better characterize drought; and (iii) extending skillful precipitation forecasts beyond a 1-month lead time.

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