| 项目编号: | 1346813
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| 项目名称: | Spring Soil Temperature Anomalies in the Western United States and Summer Droughts in the Southern Plains |
| 作者: | Yongkang Xue
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| 承担单位: | University of California-Los Angeles
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| 批准年: | 2013
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| 开始日期: | 2014-06-01
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| 结束日期: | 2018-05-31
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| 资助金额: | USD615459
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| 资助来源: | US-NSF
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| 项目类别: | Standard Grant
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| 国家: | US
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| 语种: | 英语
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| 特色学科分类: | Geosciences - Atmospheric and Geospace Sciences
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| 英文关键词: | soil temperature
; project
; southern plains
; southern plains precipitation
; frozen soil
; drought
; sea surface temperature
; experiment
; subsequent summer
; model
; soil condition
; warm land surface temperature
|
| 英文摘要: | This project seeks to understand the causes of precipitation variability in the US Southern Plains (roughly equivalent to Nebraska, Missouri, Oklahoma, Arkansas, Texas, and Louisiana). This area is among the most drought-prone in the US, and droughts in the region have substantial economic impacts. This project examines the hypothesis that Spring subsurface soil temperature anomalies in the Western US in produce rainfall changes in the Southern Plains in the subsequent summer. The hypothesized relationship is such that warm subsurface soil temperature in the West, through its manifestation in warm land surface temperature, generates a cyclonic circulation in the overlying atmosphere, which propagates eastward to produce enhanced June rainfall to the east and south of the soil temperature anomaly, with the opposite result (i.e. drought) for cold subsurface soil temperature. A further issue to be examined in the project is the effect of frozen soil on the precipitation response to soil temperature. The project tests the extent to which a better representation of frozen soil in regional climate models (RCMs) can lead to a stronger relationship between Western soil temperature and Southern Plains precipitation simulated by the model.
Preliminary work for the proposal has shown evidence for the effect of subsurface soil temperature, and work performed under the project will follow up with a set of model simulation experiments. The experiments will be conducted with a model configuration in which a global atmospheric model (the NOAA/NCEP Global Forecast System model, or GFS) will be combined with an RCM known as the Weather Research and Forecasting (WRF) model, in which land surface processes are simulated by the Simplified Simple Biosphere (SSiB) model. Experiments typically use imposed sea surface temperatures and sea ice to produce a global simulation for a particular year using the GFS model, which is in turn used to specify lateral boundary conditions for WRF simulations. The experiments test the influence of all local and remote effects on Southern Plains precipitation, including soil conditions in the Western states and also sea surface temperature (SST) fluctuations. SSTs, including those associated with El Nino can affect Southern Plains precipitation both directly and indirectly, through their influence on soil temperature to the West.
The work has broader impacts due to the economic and societal impact of drought in the Southern Plains and the desirability of better methods to predict the extent and duration of droughts. The project will also support a post-doctoral researcher, thereby supporting the next generation of scientists in this research area. |
| 资源类型: | 项目
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/96861
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| Appears in Collections: | 影响、适应和脆弱性
气候减缓与适应
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| Recommended Citation: | |
Yongkang Xue. Spring Soil Temperature Anomalies in the Western United States and Summer Droughts in the Southern Plains. 2013-01-01.
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