我国西北近50年春季沙尘暴活动的变化与气候因子相关性研究

本文根据我国西北不同地区近50年来气象观测资料,研究了该区沙尘暴活动特点及其与气候变化的关系。结果表明:近五十年来我国西北沙尘暴发生总体呈波动减小趋势,这主要与新疆和内蒙古等沙源区向暖湿方向发展有关,而1999—2002年沙尘暴活动增强的主要原因是降水减少和气温升高。气候要素中的降水量变化与沙尘暴的发生有着极其密切的关系,二者呈明显的负相关;气温的高低也与沙尘暴的发生呈负相关,但没有与降水量的关系明显。在沙尘暴多发的60—70年代,沙尘暴日数减少与春季降水量的增加关系密切;而在80—90年代,冬干气候对沙尘暴日数增加作用明显。在沙尘暴多发的60—70年代,拉尼娜年对沙尘暴日数有明显的减少作用;相反,在沙尘暴较少的80—90年代,厄尔尼诺年对沙尘暴日数有明显的增加作用。

Relationships Between the Changes of Sandstorm Activities in Spring and Climatic Factors in the Northwest China in Recent 50 Years

The sandstorms characteristics and its relationship with climate change were studied based on meterological data of recent 50 years in different regions of the Northwest of China.The study showed that the frequency of sandstorms decreasing in the recent 50 years was mainly because of the impact of the climate in sand regions such as Inner Mongolia and Xinjiang turning to warm and wet,then its increase during 1999~2000 was mainly because of more precipitation and temperature growing.The changes of precipitation had an extremely close and obviously negative relationship with the occurrence of sandstorms,the temperatures was the same but less obvious than the former.From 1960s to 1970s when sandstorm occurred frequently,its decrease had an close relationship with the precipitation's increase in spring.While during the 1980s to 1990s,the dryness in winter had an obviously effect on the increase of sandstorm.From 1960s to 1970s when the sandstorm frequently occurred,the El Nino made it decrease.While from 1980s to 1990s,the sandstorm seldom occurred,the La Nina made it increase.