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沙尘暴天气的形成要具备三个基本条件： There are three basic conditions for the formation of sandstorm: 一是要有沙源， First, there should be a source of sand, 二是要有强冷空气即大风， Second, there should be strong cold air, i.e. strong wind, 三是要有冷暖空气相互作用。沙源来自于沙漠，退化的林草地或没有植被覆盖的干松土地以及城乡建筑工地的泥沙。气旋和低压产生一种垂直的上升运动，把沙尘吹扬了起来，形成沙尘暴天气。扬沙、浮尘和沙尘暴天气的差别在气象上是以能见度加以区分的：水平能见度在1—10公里之间的为扬沙或浮尘天气。出现浮尘天气时，空中弥漫的是一些细小颗粒物，沙尘多由外地而来；扬沙天气卷起的尘土是一些较大的颗粒物，它们基本是本地产生的。而水平能见度小于1公里的就是沙尘暴天气，它属于灾害性天气现象，所带来的危害最为严重。气象专家介绍，由于沙尘暴起因包括了风力、高空大气强对流和地表状态三方面因素，而前两者属气候因素，人力不可抗拒，因此，根除沙尘暴目前尚无可能。 Third, there should be interaction between warm and cold air. The source of sand comes from deserts, degraded forest and grassland, or dry pine land without vegetation cover, as well as the sediment of urban and rural construction sites. The cyclone and the low pressure produce a vertical upward movement, which blows up the dust and forms a dust storm. The weather difference of sand blowing, floating dust and sandstorm is distinguished by visibility in meteorology: the weather with horizontal visibility between 1-10km is sand blowing or floating dust. When the floating dust weather occurs, the air is filled with some small particles, most of which come from other places; the dust rolled up by the floating dust weather is some larger particles, which are basically generated locally. The sandstorm with horizontal visibility less than 1km is a kind of disastrous weather phenomenon, which brings the most serious harm. According to meteorologists, the causes of sandstorm include wind force, high-altitude atmospheric strong convection and surface state, while the former two are climatic factors and irresistible by manpower, so it is impossible to eradicate sandstorm at present. | 
