气候变化领域集成服务门户(CCPortal): Reduced surface fine dust under droughts over the southeastern United States during summertime: observations and CMIP6 model simulations

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DOI	10.5194/acp-22-7843-2022
	Reduced surface fine dust under droughts over the southeastern United States during summertime: observations and CMIP6 model simulations
	Li, Wei; Wang, Yuxuan
发表日期	2022
ISSN	1680-7316
EISSN	1680-7324
起始页码	7843
结束页码	7859
卷号	22 期号:12 页码:17
英文摘要	Drought is an extreme hydroclimate event that has been shown to cause an increase in surface fine dust near source regions, yet the drought-dust relationship in regions predominantly influenced by long-range-transported dust such as the southeastern USA (SEUS) has received less attention. Using long-term surface fine-dust observations, the weekly US Drought Monitor (USDM), and the monthly standardized precipitation-evapotranspiration index (SPEI), this study unmasks spatial disparity in drought-dust relationships in the contiguous USA (CONUS) where the SEUS shows a decrease in surface dust concentrations during drought in contrast to the expected increase in dust found in other CONUS regions. Surface fine dust was found to decrease by similar to 0.23 mu gm(-3) with a unit decrease in SPEI in the SEUS, as opposed to an increase of similar to 0.12 mu gm(-3) in the west. The anomalies of dust elemental ratios, satellite aerosol optical depth (AOD), and dust extinction coefficients suggest that both the emissions and trans-Atlantic transport of African dust are weakened when the SEUS is under droughts. Through the teleconnection patterns of the negative North Atlantic Oscillation (NAO), a lower-than-normal and more northeastward displacement of the Bermuda High (BH) is present during SEUS droughts, which results in less dust being transported into the SEUS. At the same time, enhanced precipitation in the Sahel associated with the northward shift of the Intertropical Convergence Zone (ITCZ) leads to lower dust emissions therein. Of the 10 selected models participating in the sixth phase of the Coupled Model Intercomparison Project (CMIP6), GISS-E2-1-G was found to perform the best in capturing the drought-dust sensitivity in the SEUS. This study reveals the mechanism of how droughts influence aerosol abundance through changing long-range transport of dust.
学科领域	Environmental Sciences; Meteorology & Atmospheric Sciences
语种	英语
WOS研究方向	Environmental Sciences & Ecology ; Meteorology & Atmospheric Sciences
WOS记录号	WOS:000812213500001
来源期刊	ATMOSPHERIC CHEMISTRY AND PHYSICS
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/273258
作者单位	University of Houston System; University of Houston
推荐引用方式 GB/T 7714	Li, Wei,Wang, Yuxuan. Reduced surface fine dust under droughts over the southeastern United States during summertime: observations and CMIP6 model simulations[J],2022,22(12):17.
APA	Li, Wei,&Wang, Yuxuan.(2022).Reduced surface fine dust under droughts over the southeastern United States during summertime: observations and CMIP6 model simulations.ATMOSPHERIC CHEMISTRY AND PHYSICS,22(12),17.
MLA	Li, Wei,et al."Reduced surface fine dust under droughts over the southeastern United States during summertime: observations and CMIP6 model simulations".ATMOSPHERIC CHEMISTRY AND PHYSICS 22.12(2022):17.