autumn ice
2.By using composite and correlation analysis,it is concluded that the circulation backgrounds between more and less spring sandstorm are evidently different,and the anomalies of autumn Greenland sea-ice can affect the occurrence of sandstorm in the following spring in Ningxia through impacting the atmospheric circulation background.
3.The results showed that the total sea ice in 2003 was obviously lighter than that in 1999.Sea ice cover was decreased in the spring and autumn of 2003. The sea water coming from Bering Sea passed the Bering Strait and entered into the Chukchi Sea half month earlier than that in 1999,which caused the sea ice melt seriously.

