The Principal Character Of Sandstorm In Shaanxi And Research On Its Forecasting

Focusing on the need of forecasting spring sandstorm trend operation currently developed on provincial meteorology department, the spatial and temporal distribution features of sandstorm in Shaanxi are analyzed based on weather data from 1954 to 2004 and the variational trend and decades' variation features are emphasized. The sandstorms in Shaanxi mainly occur in spring, mostly in the northern Shanbei where lies in the south edge of MaoWuSu desert along the Great Wall.The object of forecast research is spring sandstorm in Shaanxi.The annual and spring's sandstorm in Shaanxi exist obvious decreasing trend and obvious decades' variation features. It abruptly alternates from more to less in 1985 .The typical fewer sandstorm years all occur after 1985. Compared with 30 years' average from 1971 to 2000, only in 2000 spring sandstorm is equal to the average during 16 years from 1989 to 2004,and other 15 years are less by 20%. From 2002 to 2004 three continuous years sandstorms are less by 80%. 2003 is the least year in Shaanxi since 1961.Heavy and severe sandstorm processes in Shaanxi province are firstly picked up and analyzed. The circulations, affecting systems, the cold air paths, the sand sources and paths which causing heavy sandstorm processes in Shaanxi are sorted.Based on the diagnosis and analysis about the cause of the spring sandstorm, forecasting train of thoughts in Shaanxi is brought forward. The forecast notion models and regress statistic models are given and applied in sandstorm trend forecast in 2003-2004, and the results are right and the effect is well. Two problems existing in sandstorm research are found, which probably brings the confusion of records counting and analysis difference in heavy sandstorm. These questions are analyzed and discussed in this article. Then the disposal methods are brought forward and the importance of making these questions clear is pointed outThis is just primary result and more discussion should be brought forward. This is just the beginning.