气候变化领域集成服务门户(CCPortal): Effect of dust on rainfall over the Red Sea coast based on WRF-Chem model simulations

CCPortal

DOI	10.5194/acp-22-8659-2022
	Effect of dust on rainfall over the Red Sea coast based on WRF-Chem model simulations
	Parajuli, Sagar P.; Stenchikov, Georgiy L.; Ukhov, Alexander; Mostamandi, Suleiman; Kucera, Paul A.; Axisa, Duncan; Gustafson, William I., Jr.; Zhu, Yannian
发表日期	2022
ISSN	1680-7316
EISSN	1680-7324
起始页码	8659
结束页码	8682
卷号	22 期号:13 页码:24
英文摘要	Water is the single most important element of life. Rainfall plays an important role in the spatial and temporal distribution of this precious natural resource, and it has a direct impact on agricultural production, daily life activities, and human health. One of the important elements that govern rainfall formation and distribution is atmospheric aerosol, which also affects the Earth's radiation balance and climate. Therefore, understanding how dust compositions and distributions affect the regional rainfall pattern is crucial, particularly in regions with high atmospheric dust loads such as the Middle East. Although aerosol and rainfall research has garnered increasing attention as both an independent and interdisciplinary topic in the last few decades, the details of various direct and indirect pathways by which dust affects rainfall are not yet fully understood. Here, we explored the effects of dust on rainfall formation and distribution as well as the physical mechanisms that govern these phenomena, using high-resolution WRF-Chem simulations (similar to 1.5 km x 1.5 km) configured with an advanced double-moment cloud microphysics scheme coupled with a sectional eight-bin aerosol scheme. Our model-simulated results were realistic, as evaluated from multiple perspectives including vertical profiles of aerosol concentrations, aerosol size distributions, vertical profiles of air temperature, diurnal wind cycles, and spatiotemporal rainfall patterns. Rainfall over the Red Sea coast is mainly caused by warm rain processes, which are typically confined within a height of similar to 6 km over the Sarawat mountains and exhibit a strong diurnal cycle that peaks in the evening at approximately 18:00 local time under the influence of sea breezes. Numerical experiments indicated that dust could both suppress or enhance rainfall. The effect of dust on rainfall was calculated as total, indirect, and direct effects, based on 10-year August-average daily-accumulated rainfall over the study domain covering the eastern Red Sea coast. For extreme rainfall events (domain-average daily-accumulated rainfall of >= 1.33 mm), the net effect of dust on rainfall was positive or enhancement (6.05 %), with the indirect effect (4.54 %) and direct effect (1.51 %) both causing rainfall increase. At a 5 % significance level, the total and indirect effects were statistically significant whereas the direct effect was not. For normal rainfall events (domain-average daily-accumulated rainfall <1.33 mm), the indirect effect enhanced rainfall (4.76 %) whereas the direct effect suppressed rainfall (-5.78 %), resulting in a negative net suppressing effect (-1.02 %), all of which were statistically significant. We investigated the possible physical mechanisms of the effects and found that the rainfall suppression by dust direct effects was mainly caused by the scattering of solar radiation by dust. The surface cooling induced by dust weakens the sea breeze circulation, which decreases the associated landward moisture transport, ultimately suppressing rainfall. For extreme rainfall events, dust causes net rainfall enhancement through indirect effects as the high dust concentration facilitates raindrops to grow when the water vapor is sufficiently available. Our results have broader scientific and environmental implications. Specifically, although dust is considered a problem from an air quality perspective, our results highlight the important role of dust on sea breeze circulation and associated rainfall over the Red Sea coastal regions. Our results also have implications for cloud seeding and water resource management.
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:000821043600001
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/273198
作者单位	King Abdullah University of Science & Technology; National Center Atmospheric Research (NCAR) - USA; University of California System; University of California San Diego; Scripps Institution of Oceanography; United States Department of Energy (DOE); Pacific Northwest National Laboratory; Nanjing University
推荐引用方式 GB/T 7714	Parajuli, Sagar P.,Stenchikov, Georgiy L.,Ukhov, Alexander,et al. Effect of dust on rainfall over the Red Sea coast based on WRF-Chem model simulations[J],2022,22(13):24.
APA	Parajuli, Sagar P..,Stenchikov, Georgiy L..,Ukhov, Alexander.,Mostamandi, Suleiman.,Kucera, Paul A..,...&Zhu, Yannian.(2022).Effect of dust on rainfall over the Red Sea coast based on WRF-Chem model simulations.ATMOSPHERIC CHEMISTRY AND PHYSICS,22(13),24.
MLA	Parajuli, Sagar P.,et al."Effect of dust on rainfall over the Red Sea coast based on WRF-Chem model simulations".ATMOSPHERIC CHEMISTRY AND PHYSICS 22.13(2022):24.