| The source regions,transmission path,spatial-temporal distribution characteristics and mechanism of dust aerosol are of great scientific value for the study of climate and environmental effects of sand-dust weather.This paper uses the observational records of 90ground meteorological stations and satellite observational data of the Arabian Peninsula from1997 to 2016(nearly 20 years)to analyze the spatial-temporal distribution characteristics and change rules of sand-dust weather,and summarizes its formation process and reasons based on meteorological conditions.This paper uses the observation records and satellite observation data of 90 ground weather stations in Arabian Peninsula from 1997 to 2016(nearly 20 years)to analyze the temporal and spatial distribution characteristics and variation rules of sand-dust weather,and summarizes its formation process and causes in combination with meteorological conditions.The HYSPLIT trajectory model is used to determine the sand-dust transmission path.Finally,the WRF-Chem model is used to simulate the amount and distribution of sand-dust weather,and the simulated amount of dust devil is added to obtain the total amount of dust aerosol in the Arabian Peninsula.The research conclusions are as follows:(1)The occurrence frequency of dust storms and floating dust is the largest in intensity and range from June to July,and gradually decreases after August,with the occurrence frequency of dust storms being the lowest in October to November.The spatial distribution of dust sources is slightly different from each other.Sand storm occur most frequently in the"Permanently dusty areas"formed by the An-Nafud desert,the An-Dahna desert and the west coast of the Persian Gulf.Besides the"Permanently dusty areas",there are also high-value centers in the northern Hijaz Mountains and along the coast of the Persian Gulf.(2)The AI index observed by satellite has a relatively high value center similar to"inverted arrow".The arrow trunk is composed of"Permanent dusty area",and the left and right wings are mainly composed of Rub'al Khali desert and Oman area.The monthly index of AI index is basically consistent with the observed data,and it is more frequent in spring and summer,with obvious symmetrical single peak distribution characteristics.(3)There are low-pressure centers and low-temperature centers at high levels when dust occurs.The northwest wind behind the trough introduces cold air into the Arabian Peninsula,forming a cold front to pass through and produce sand-dust weather.Backward trajectory clustering analysis shows that there are three types of dust transmission paths in the peninsula:1)the dust source region of the local desert;2)the main long-distance dust source is the Sahara Desert;and 3)the transmission from Iraq and Iran.(4)WRF-Chem model simulates that the annual average of total sediment yield in Arabian Peninsula is 52g/m~2,and the contribution rate of dust devil to total sediment yield is8%.From the monthly time distribution,aerosol in Arabian Peninsula is more obvious in spring and summer,reaching the highest value in the whole year from June-July,and the occurrence of sand-dust weather in winter is relatively weak.The source area of dust has been revised by adding the amount of dust devil.The main dust area is concentrated in the eastern part of the peninsula.It extends from the Tigris-Euphrates alluvial plain through Iraq to Kuwait and Qatar along the Persian Gulf coast,northeast Saudi Arabia,An-Dahna desert,Rub'al Khali desert and the coastal areas in southern Oman to form an uninterrupted continuous sand and dust belt.In addition,there are the western Red Sea coastal plain and the sand and dust area along the Yemeni coast. |
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