狂风骤起,天地闭合,沙尘弥漫,人们呼吸困难,每年春天都会出现影响人们生产和生活的极端天气——沙尘天气(如图1),生活在我国北方的人们对这种特有的天气不会陌生.据统计,20世纪50年代,强沙尘暴在我国发生过5次,60年代发生过8次,70年代发生过13次,80年代发生过14次,90年代发生过23次;进入21世纪以来,沙尘暴发生率急剧增加,呈现出时间早、危害大的特点,并且波及的范围愈来愈广,造成的损失愈来愈重.沙尘暴是由于不稳定的热力条件,在风力加大、强对流作用下,强风将沙尘裹挟一并吹起,并卷扬得很高,从沙源地携至新的目的地.沙、尘源是沙尘暴的 When the gust of wind rises, the earth is closed, the dust is filled, and people breathe hard. Every spring there are extreme weather-sand and dust weather (Figure 1) that affects people’s production and life. People living in the north of our country have such particular weather According to statistics, in the 1950s, strong sandstorms occurred in our country 5 times, in the 60s 8 times, 70s in the past 13 times, 80s in the past 14 times and 90s in 23 times; Since the 21st century, the incidence of sandstorms has risen sharply, showing the characteristics of early time and great harm, and the spread of sandstorms has become more and more widespread with more and more losses. The sandstorm is due to unstable thermal conditions, , The strong convection, the strong wind blowing sand and dust together, and was hoisted very high, from the sand source to a new destination. Sand, dust source is dust storm