关键词: 中国西北干旱区, 沙尘暴天气过程, 特征, 成因

Abstract: Based on the available original sand-dust storm data observed at 131 meteorological stations from 1954 to 2001 in arid regions of Northwest China, the characteristics and cause of regional sand-dust storm process happened within 48 years was analyzed with statistics methods such as Mexican Hat Wavelet. It is shown that 1975 regional sand-dust storm processes and 247 regional strong sand-dust storm processes have been confirmed from 1954 to 2001 in arid regions of Northwest China. The spatial distribution of regional sand-dust storm process and regional strong sand-dust storm process is coincident. Tarim Basin and the eastern part of Northwest China are two frequently occurred areas of sand-dust storms. The regional sand-dust storm processes concentrate in March to July, while strong sand-dust storm processes in March to May. Whether regional sand-dust storm processes or strong sand-dust storm processes all have reduced fluctuantly from 1954 to 2001, during which time from 1956 to 1987 was the most frequently occurred period, and since 1988 all reduced obviously. The Atlantic Oscillation index in February has forecasting significance for the number of regional sand-dust storm process in the same year.

Key words: arid regions of Northwest China, regional sand-dust storm process, characteristics, cause