气候变化领域集成服务门户(CCPortal): Characterizing the relationship between temperature and soil moisture extremes and their role in the exacerbation of heat waves over the contiguous United States

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DOI	10.1175/JCLI-D-20-0440.1
	Characterizing the relationship between temperature and soil moisture extremes and their role in the exacerbation of heat waves over the contiguous United States
	Benson D.O.; Dirmeyer P.A.
发表日期	2021
ISSN	08948755
起始页码	2175
结束页码	2187
卷号	34 期号:6
英文摘要	Increased heat-wave frequency across the United States has led to the need for improved predictability of heat-wave events. A detailed understanding of land-atmosphere interactions and the relationship between soil moisture and temperature extremes could provide useful information for prediction. This study identifies, for many locations, a threshold of soil moisture below which there is an increase in the sensitivity of atmospheric temperature to declining soil moisture. This shift to a hypersensitive regime causes the atmosphere to be more susceptible to atmospherically driven heatwave conditions. The soil moisture breakpoint where the regime shift occurs is estimated using segmented regression applied to observations and reanalysis data. It is shown that as the soil gets drier, there is a concomitant change in the rate of decrease in latent heat flux and increase in sensible heat flux leading to a strong positive feedback of increased air temperature near the surface, which further dries out the soil. Central, southwestern, and southeastern parts of the United States seem to have regions of clear regime shifts, while the eastern part of the United States generally does not get dry enough to reveal significant breakpoints. Sensible heat flux is seen to be a primary driver of this increased temperature sensitivity aided by the drop in latent heat flux. An investigation of flux tower sites verifies the breakpoint-flux relationships found in reanalysis data. Accurate estimation of these breakpoints can contribute to improved heat-wave prediction. © 2021 American Meteorological Society.
英文关键词	Atmosphere-land interaction; Extreme events; Reanalysis data; Soil moisture; Surface fluxes; Temperature
语种	英语
scopus关键词	Climatology; Heat flux; Latent heat; Soil moisture; Accurate estimation; Air temperature; Improved predictability; Increased temperature; Land atmosphere interaction; Segmented regressions; Sensible heat flux; Temperature extremes; Atmospheric temperature; atmosphere-biosphere interaction; extreme event; heat wave; regional climate; soil moisture; surface temperature; temperature profile; United States
来源期刊	Journal of Climate
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/178662
作者单位	George Mason University, Fairfax, VA, United States; Center for Ocean-Land-Atmosphere Studies, George Mason University, Fairfax, VA, United States
推荐引用方式 GB/T 7714	Benson D.O.,Dirmeyer P.A.. Characterizing the relationship between temperature and soil moisture extremes and their role in the exacerbation of heat waves over the contiguous United States[J],2021,34(6).
APA	Benson D.O.,&Dirmeyer P.A..(2021).Characterizing the relationship between temperature and soil moisture extremes and their role in the exacerbation of heat waves over the contiguous United States.Journal of Climate,34(6).
MLA	Benson D.O.,et al."Characterizing the relationship between temperature and soil moisture extremes and their role in the exacerbation of heat waves over the contiguous United States".Journal of Climate 34.6(2021).