关键词: 中国北方, 沙尘暴, 气候成因, 趋势预测

Abstract: Since the beginning of 1980's, the sun activity has enhanced; the world climate becomes warmer; the intensity of the surface heat-field in Tibetan plateau enhances; the westerly rushing current axis of Euasia moves towards north;the situation of the subtropical high pressure of the west Pacific Ocean is more northwest than that in normal years, and its strength enhances; Mongolia cyclone becomes weaker; the precipitation at the dust source region increases in the Northern China. All the above make sandstorm reduce in the northern China. From the end of 20^th century to the beginning of 21^st, the sun activity begins a new round of weak trend , which weakens the warm trend of climate, causes the air temperature lower gradually, the intensity of the surface heat-field in Tibetan plateau trial off, and Mongolia cyclone strengthen gradually. It is forecasted that the sandstorm in northern China will wavely increase gradually, entering a new round of relatively active period. Considering the intensity of the surface heat-field in Tibetan plateau was weaker at the beginning of winter in 2003/2004, the air temperature of the Northern Xinjiang, Hexi corridor and Ningxia region etc is abnormally lower, and Mongolia cyclone is obviously strong at the end of winter in 2004, we predict the sand-dust storms in northern China in 2004 will be obviously more than that in the past few years. The region of enhancing sand-dust storm mainly situates in the central and the west part of China.

Key words: northern China, sand-dust storm, climatic causes of formation, trend forecast