中国北方沙尘暴气候成因及未来趋势预测

Climatic Cause of Sand-dust Storm Formation in Northern China and its Trend Forecast

20世纪80年代以来的太阳活动加强,全球气候变暖,青藏高原地面加热场强度加强,欧亚西风急流轴北移,西太平洋副热带高压偏北偏西、强度加强,蒙古气旋减弱,西北西部的沙尘源区降水增加,是中国北方沙尘暴减少的主要原因。20世纪末到21世纪初太阳活动开始进入新一轮的减弱期,引起气候变暖趋势减弱,气温上升趋势减缓,青藏高原地面加热场强度减弱,蒙古气旋逐渐加强。预计未来中国北方沙尘暴在波动中逐渐增加,进入新一轮的相对活跃期。考虑到2003/2004年前冬(12～1月)青藏高原地面加热场强度偏弱,新疆北部、河西走廊及宁夏等地气温异常偏低,后冬(1～3月)蒙古气旋明显加强。预计2004年中国北方沙尘暴明显比近年偏多。偏多地区主要在中、西部。

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.