scholarly journals Assessment of observed and model-derived soil moisture-evaporative fraction relationships over the United States Southern Great Plains

2014 ◽  
Vol 119 (11) ◽  
pp. 6279-6291 ◽  
Author(s):  
Trent W. Ford ◽  
Christoph O. Wulff ◽  
Steven M. Quiring
Keyword(s):  
United States ◽  
Soil Moisture ◽  
Great Plains ◽  
The United States ◽  
Evaporative Fraction ◽  
Southern Great Plains

scholarly journals Primary Atmospheric Drivers of Pluvial Years in the United States Great Plains

2018 ◽  
Vol 19 (4) ◽  
pp. 643-658 ◽  
Author(s):  
Paul X. Flanagan ◽  
Jeffrey B. Basara ◽  
Jason C. Furtado ◽  
Xiangming Xiao
Keyword(s):  
United States ◽  
Great Plains ◽  
Heavy Precipitation ◽  
The United States ◽  
Precipitation Variability ◽  
Northern Great Plains ◽  
Southern Great Plains ◽  
The Public ◽  
Moisture Fluxes ◽  
Precipitation Events

Abstract Precipitation variability has increased in recent decades across the Great Plains (GP) of the United States. Drought and its associated drivers have been studied in the GP region; however, periods of excessive precipitation (pluvials) at seasonal to interannual scales have received less attention. This study narrows this knowledge gap with the overall goal of understanding GP precipitation variability during pluvial periods. Through composites of relevant atmospheric variables from the ECMWF twentieth-century reanalysis (ERA-20C), key differences between southern Great Plains (SGP) and northern Great Plains (NGP) pluvial periods are highlighted. The SGP pluvial pattern shows an area of negative height anomalies over the southwestern United States with wind anomalies consistent with frequent synoptic wave passages along a southward-shifted North Pacific jet. The NGP pattern during pluvial periods, by contrast, depicts anomalously low heights in the northwestern United States and an anomalously extended Pacific jet. Analysis of daily heavy precipitation events reveals the key drivers for these pluvial events, namely, an east–west height gradient and associated stronger poleward moisture fluxes. Therefore, the results show that pluvial years over the GP are likely driven by synoptic-scale processes rather than by anomalous seasonal precipitation driven by longer time-scale features. Overall, the results present a possible pathway to predicting the occurrence of pluvial years over the GP and understanding the causes of GP precipitation variability, potentially mitigating the threats of water scarcity and excesses for the public and agricultural sectors.

Investigating the Relationship between the Evaporative Stress Index and Land Surface Conditions in the Contiguous United States

2020 ◽  
Vol 21 (7) ◽  
pp. 1469-1484
Author(s):  
Yafang Zhong ◽  
Jason A. Otkin ◽  
Martha C. Anderson ◽  
Christopher Hain
Keyword(s):  
United States ◽  
Soil Moisture ◽  
Great Plains ◽  
Land Surface ◽  
The United States ◽  
Stress Index ◽  
Northern Great Plains ◽  
Reference Network ◽  
North Central ◽  
Central United States

AbstractDespite the key importance of soil moisture–evapotranspiration (ET) coupling in the climate system, limited availability of soil moisture and ET observations poses a major impediment for investigation of this coupling regarding spatiotemporal characteristics and potential modifications under climate change. To better understand and quantify soil moisture–ET coupling and relevant processes, this study takes advantage of in situ soil moisture observations from the U.S. Climate Reference Network (USCRN) for the time period of 2010–17 and a satellite-derived version of the evapotranspiration stress index (ESI), which represents anomalies in a normalized ratio of actual to reference ET. The analyses reveal strong seasonality and regional characteristics of the ESI–land surface interactions across the United States, with the strongest control of soil moisture on the ESI found in the southern Great Plains during spring, and in the north-central United States, the northern Great Plains, and the Pacific Northwest during summer. In drier climate regions such as the northern Great Plains and north-central United States, soil moisture control on the ESI is confined to surface soil layers, with subsurface soil moisture passively responding to changes in the ESI. The soil moisture–ESI interaction is more uniform between surface and subsurface soils in wetter regions with higher vegetation cover. These results provide a benchmark for simulation of soil moisture–ET coupling and are useful for projection of associated climate processes in the future.

scholarly journals Irrigation Effects on Land–Atmosphere Coupling Strength in the United States

2017 ◽  
Vol 30 (10) ◽  
pp. 3671-3685 ◽  
Author(s):  
Yaqiong Lu ◽  
Keith Harding ◽  
Lara Kueppers
Keyword(s):  
United States ◽  
Soil Moisture ◽  
Water Vapor ◽  
Great Plains ◽  
Coupling Strength ◽  
Climate Models ◽  
The United States ◽  
Lower Sensitivity ◽  
Local Soil ◽  
Irrigation Effects

Abstract Land–atmosphere coupling strength describes the degree to which the atmosphere responds (e.g., via changes in precipitation) to changes in the land surface state (e.g., soil moisture). The Midwest and Great Plains of the United States have been shown to be “hot spots” of coupling by many climate models and some observations. However, very few of the modeling studies have reported whether the climate models applied irrigation in the Midwest and Great Plains, where 24%–27% of farmland is irrigated, leaving open the question of whether irrigation affects current estimates of coupling strength. This study used a regional climate model that incorporated dynamic crop growth and precision irrigation (WRF3.3–CLM4crop) to investigate irrigation effects on land–atmosphere coupling strength. Coupling strength was quantified using multiple indices and the irrigated land-induced precipitation was tracked using a back trajectory method. The indices showed a consistent and significant decline in local coupling strength with irrigation in the Midwest and northern Great Plains. These reductions were due to increased soil moisture but decreased local precipitation and lower sensitivity of latent heat flux to soil moisture over irrigated regions. The back trajectories of water vapor transport confirmed that irrigation largely did not contribute to local precipitation. Water vapor from irrigated land was transported to the Midwest and U.S. Northeast where it fell as precipitation, suggesting that irrigation has a broader spatial impact on soil moisture–precipitation coupling than simply through local soil moisture–evapotranspiration coupling. The present study suggests that climate models without irrigation schemes may overestimate the land–atmosphere coupling strength over irrigated agricultural regions but underestimate coupling strength over neighboring nonirrigated regions.

scholarly journals A comparison of multiscale variations of decade-long cloud fractions from six different platforms over the Southern Great Plains in the United States

2014 ◽  
Vol 119 (6) ◽  
pp. 3438-3459 ◽  
Author(s):  
Wei Wu ◽  
Yangang Liu ◽  
Michael P. Jensen ◽  
Tami Toto ◽  
Michael J. Foster ◽  
...  
Keyword(s):  
United States ◽  
Great Plains ◽  
The United States ◽  
Southern Great Plains

scholarly journals Drought and Pluvial Dipole Events within the Great Plains of the United States

2015 ◽  
Vol 54 (9) ◽  
pp. 1886-1898 ◽  
Author(s):  
Jordan Christian ◽  
Katarina Christian ◽  
Jeffrey B. Basara
Keyword(s):  
United States ◽  
Standard Deviation ◽  
Great Plains ◽  
Spatial Scales ◽  
The United States ◽  
Northern Great Plains ◽  
High Plains ◽  
Southern Great Plains ◽  
One Year ◽  
The U.S

AbstractThe purpose of this study was to quantify dipole events (a drought year followed by a pluvial year) for various spatial scales including the nine Oklahoma climate divisions and the author-defined regions of the U.S. Southern Great Plains (SGP), High Plains (HP), and Northern Great Plains (NGP). Analyses revealed that, on average, over twice as many standard deviation (STDEV) dipoles existed in the latter half of the dataset (1955–2013) relative to the first half (1896–1954), suggesting that dramatic increases in precipitation from one year to the next within the Oklahoma climate divisions are increasing with time. For the larger regions within the Great Plains of the United States, the percent chance of a significant pluvial year following a significant drought year was approximately 25% of the time for the SGP and NGP and approximately 16% of the time for the HP. The STDEV dipole analyses further revealed that the frequency of dipoles was consistent between the first and second half of the dataset for the NGP and HP but was increasing with time in the SGP. The temporal periods of anomalous precipitation during relative pluvial years within the STDEV dipole events were unique for each region whereby October occurred most frequently (70%) within the SGP, September occurred most frequently (60%) within the HP, and May occurred most frequently (62%) within the NGP.

The Temporal Evolution of Convective Indices in Storm-Producing Environments

2008 ◽  
Vol 23 (5) ◽  
pp. 786-794 ◽  
Author(s):  
Timothy J. Wagner ◽  
Wayne F. Feltz ◽  
Steven A. Ackerman
Keyword(s):  
United States ◽  
Temporal Resolution ◽  
Great Plains ◽  
Wind Shear ◽  
Temporal Evolution ◽  
The United States ◽  
Severe Weather ◽  
Wind Profiler ◽  
Southern Great Plains ◽  
Tornadic Storms

Abstract Temporal changes in stability and shear associated with the development of thunderstorms are quantified using the enhanced temporal resolution of combined Atmospheric Emitted Radiance Interferometer (AERI) thermodynamic profile retrievals and National Oceanic and Atmospheric Administration (NOAA) 404-MHz wind profiler observations. From 1999 to 2003, AERI systems were collocated with NOAA wind profilers at five sites in the southern Great Plains of the United States, creating a near-continuous dataset of atmospheric soundings in both the prestorm and poststorm environments with a temporal resolution of up to 10 min between observations. Median values for several standard severe weather indices were calculated for tornadic storms and nontornadic supercells. It was found that instability generally increases throughout the preconvective period, reaching a peak roughly 1 h before a tornado forms or a nontornadic supercell forms large hail. Wind shear for both tornadic and nontornadic storms starts to increase roughly 3 h before storm time. However, indices are highly variable between time and space and may not be representative of the environment at large.

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