In this paper,the temporal variation characteristics of the dust storm in North China are investigated.Based on power spectrum analysis and wavelet analysis,1956-1970 and 1985-1999 are chosen as the high-frequency and...In this paper,the temporal variation characteristics of the dust storm in North China are investigated.Based on power spectrum analysis and wavelet analysis,1956-1970 and 1985-1999 are chosen as the high-frequency and low-frequency dust storm decades respectively.Analysis results clearly show that the spring and wintertime anomalous atmospheric circulation between these two dec-ades are significantly different.Compared with the former decade,there are a strengthened polar vortex,enhanced westerlies near 50°N,and a weak East Asian major though in the winter of the latter decade.The north and center parts of the Siberian high and the Aleutian low become weak.The southerly and easterly wind anomalies appear over the north and east parts of China,which implies the weakening of East Asian winter monsoon.Meanwhile,northern China experiences warmer winters and wetter springs,which are in favor of the weakening of dust storm intensity in North China.There are significant out-of-phase relationships between dust frequency and wintertime westerly intensity,as well as between dust frequency and Arctic Oscillation.It is also found that the frequency of dust weather is strongly re-lated to winter-springtime East Asian monsoon intensity.展开更多
基金This research was jointly supported by the Chinese Academy of Sciences(Grant No.KZCX3-SW-221)the National Natural Science Foundation of China(Grants No.40125014 and 40475037).
文摘In this paper,the temporal variation characteristics of the dust storm in North China are investigated.Based on power spectrum analysis and wavelet analysis,1956-1970 and 1985-1999 are chosen as the high-frequency and low-frequency dust storm decades respectively.Analysis results clearly show that the spring and wintertime anomalous atmospheric circulation between these two dec-ades are significantly different.Compared with the former decade,there are a strengthened polar vortex,enhanced westerlies near 50°N,and a weak East Asian major though in the winter of the latter decade.The north and center parts of the Siberian high and the Aleutian low become weak.The southerly and easterly wind anomalies appear over the north and east parts of China,which implies the weakening of East Asian winter monsoon.Meanwhile,northern China experiences warmer winters and wetter springs,which are in favor of the weakening of dust storm intensity in North China.There are significant out-of-phase relationships between dust frequency and wintertime westerly intensity,as well as between dust frequency and Arctic Oscillation.It is also found that the frequency of dust weather is strongly re-lated to winter-springtime East Asian monsoon intensity.
