What is the weather system that causes sandstorms?

The weather system that causes sandstorms in China is a cold front in spring.

China satellite meteorological expert system analyzes six characteristics of sandstorm.

1. Time: Sandstorms in China mainly occur from March to April. Taking 2002 as an example, there were sandstorms 12 times in China, including 4 strong sandstorms, all of which occurred in March and April. All the above processes were monitored and analyzed by the National Satellite Meteorological Center.

2. Geography: Sandstorms mainly occur in east longitude 1 10-north latitude17 degrees, that is, the vast area north of 38 degrees north latitude, that is, taking Cangzhou, Hebei as the boundary, reaching Tianjin and Beijing to Inner Mongolia in the north, passing Shijiazhuang, Yinchuan, Lanzhou and Qilian in Qinghai in the west, and reaching north.

Source: The main source of sandstorms in China is Mongolia and even the desert areas in Central Asia. This kind of sandstorm is strong, and its influence is obviously greater than that of sandstorm in China. The source of China is the Hexi Corridor in Gansu, southern Inner Mongolia, northern Hebei and other desert areas.

Four. Path: In recent years, especially last spring, there are four main paths of sandstorms affecting Beijing: one is the path of Mongolia-Inner Mongolia-Beijing turning to the northeast. The second is the route from Hexi Corridor to Beijing. Third, it influences Beijing from Zhu Rihe in Inner Mongolia via Zhangjiakou in Hebei. The fourth is to influence Beijing from the northern plateau of Shanxi to the east.

5. Related factors: Based on the preliminary analysis of the main sand-dust processes in Huahua area since 1998, especially since 2002, and related climatic factors, namely, ground vegetation, snow in February, 0- 10 cm soil humidity and temperature, it is considered that sand-dust weather is closely related to cold air activities in spring. When the cold air path is west or south in spring, for example, in April of 1999, North China. On the contrary, when the main cold air moves eastward and northward, such as April 2000 and March 2002, the main process takes place in North China.

6. Impact of sandstorm: Strong sandstorm not only affects northwest, north, central and east China, but also can be transported to northeast China, affecting northeast, far east and even north China, which is caused by global atmospheric circulation.

The forecast analysis of dust flux and dust flux in the numerical forecast experiment of sandstorm weather in China shows that when the diameter of dust particles is less than 22 microns, it is in good agreement with the ground observation data, and the forecast effect of sandstorm in China is very good. Ground vegetation data and soil types are very sensitive to sandstorm forecast.