Temporal and spatial distribution and long-range transport pathway of dust weather in North Africa
PAN Lin, HAN Yong-xiang, LU Zheng-qi, ZHAO Tian-liang
Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, Nanjing University of Information Science and Technology, Nanjing 210044, China
Based on the analysis of the temporal and spatial distribution of the dust storms, the floating dust, the wind fields and the aerosol indices (AI) in winter and summer at 300 weather stations in North Africa over the past 20 years, the long-distance transport pathways of the dust aerosols were discussed. The conclusions were as follows. 1) There were six major sand source areas in North Africa:Algeria, Mauritania, Niger and Central Chad, Eastern Egypt, Northern Sudan and Bodélé depression. The range and intensity of sandstorms were largest in March, and drop to their minimum between August and November. After November, a dust-drifting belt was gradually formed in the Sahel region, with the largest range and intensity in March, and then suppressed and divided into 3~4 minor dust-drifting zones during June and October. 2) Affected by the high surface pressure in winter and spring, the Sahel dust belt originated from the long-range transport of dust aerosols from the sandstorms in the north. Between April and August, the southerly wind from the equator moved northward, and then converged with the northwesterly wind from the Atlantic Ocean at Midwest Sahel, forming a quiet wind zone, which caused the shrink and fracture of the large dust-drifting belts. 3) There were two main dust transport pathways in North Africa, one (I) was from Algeria to the Mediterranean, Egypt and Sudan, then to Sahel, and from east to west to the Atlantic Ocean; the other one (II) was from Algeria to Mauritania and to the Atlantic Ocean from south to west; at the same time, there were four branch paths in main transmission path I.
潘琳, 韩永翔, 陆正奇, 赵天良. 北非沙尘天气时空分布特征及其远程传输路径[J]. 中国环境科学, 2020, 40(1): 76-84.
PAN Lin, HAN Yong-xiang, LU Zheng-qi, ZHAO Tian-liang. Temporal and spatial distribution and long-range transport pathway of dust weather in North Africa. CHINA ENVIRONMENTAL SCIENCECE, 2020, 40(1): 76-84.
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