我国北方沙尘暴年代际变化与北大西洋海气系统年代际变率的联系

The Relationship between Decadal Variation of Sand-Dust Storm in North China and Decadal Variability of North Atlantic Air-Sea System

分析了近50年我国北方沙尘暴的年代际变化和热盐环流(THC)的年代际变率的演变特征,发现沙尘暴与THC存在一定的联系。这种相互联系的演变过程大致是:THC与北大西洋涛动(NAO)有联系,NAO与西伯利亚冷高压有联系,而西伯利亚高压又影响北半球冷空气活动,最终影响我国北方沙尘暴的发生。结果表明,THC强(弱)→NAO弱(强)→西伯利亚高压强(弱)→地面偏北风强(弱)→沙尘暴偏多(少)。而且,在20世纪70年代末到80年代初,均存在一个明显的转折变化,即THC、西伯利亚高压和地面北风从强到弱,NAO从弱到强,沙尘暴则出现由偏多到偏少的变化趋势。

In this paper,the characteristics between the decadal variation of sand-storm in north China and decadal variability of thermohaline circulation（THC） in recent 50 years are analyzed.It is found that there are some relationships between the sand-dust storm and THC.Further analyses indicate the primary process of this following relationship： THC influences on NAO,NAO on Siberia high,Siberia high on cold air activities,and then,on the sand-dust storm.The results show that when THC is strong（weak）,NAO is weak（strong）,Siberia and north winds in surface are strong（weak）,sand-dust storms are more（less）.Moreover,a remarkable variation from the end of the 1970＇s to the beginning of 1980＇s is also found that THC,Siberia high and north wind changed from strong to weak,NAO from weak to strong and sand-dust storm in north China obviously decreased.