What are the characteristics of "sandstorm" weather in the north?

Sandstorm weather mainly occurs in late spring and early summer. This is because there is little precipitation in winter and spring in arid areas, the surface is unusually dry and loose, and the wind erosion resistance is very weak. When there is a strong wind blowing, a lot of dust will be involved in the air, forming sandstorm weather.

Globally, sandstorms mostly occur in inland desert areas, mainly the Sahara desert in Africa, and the midwest of North America and Australia are also one of the sources of sandstorms. 1933- 1937 Due to severe drought, a famous bowl-shaped sandstorm occurred in the midwest of North America. Asian sandstorm activity centers are mainly located in the Jordanian desert, Lower Mesopotamia between Baghdad and the northern coast of the Gulf, the southern Iranian coast near Abbas and the northern Afghan plain. Kazakhstan, Uzbekistan and Turkmenistan in Central Asia of the former Soviet Union are all affected areas with frequent sandstorms (≥ 15/ year), but their centers are on the sandy plain between Caspian Sea and Aral Sea and Amu Darya River.

Due to its unique geographical environment, the northwest of China is also a region where sandstorms frequently occur. The main source areas are Gurbantunggut Desert, Taklimakan Desert, Badain Jaran Desert, Tengger Desert, Wulanbuhe Desert and Mu Us Desert.

From 1999 to the spring of 2002, there were 53 sandstorms in China (1999, 2000 14, 2006 18 and 2002 12). This is the research result released by Li Huang, deputy director of China Meteorological Bureau, to the media on July 2nd. He said that in the spring of 2002, there were 12 sandstorms in northern China. It has three characteristics: concentrated occurrence period, strong occurrence intensity and wide influence range. The sources of dust weather affecting China can be divided into two types: overseas and domestic. The analysis shows that two-thirds of the dusty weather originated in southern Mongolia and was supplemented by dusty materials when passing through northern China. The sand source in China is only about one third. The dusty weather in Central Asia (Kazakhstan) is unlikely to affect the eastern part of Northwest China or even North China. The Taklimakan Desert in southern Xinjiang is a high incidence area of sandstorm weather in China, but it generally does not affect the eastern part of northwest China and North China. The path of sandstorm weather in China can be divided into northwest path, west path and north path: northwest path 1. Sandstorm weather generally originates in the central and western plateau of Mongolia or Alashan Plateau in western Inner Mongolia, and mainly affects northwest and north China. Northwest Route 2. Dust weather originated in southern Mongolia or central and western Inner Mongolia, mainly affecting the eastern part of northwest China, northern North China and most of northeast China; To the west, dusty weather originated in Gobi area in southwest or south Mongolia and desert area in western Inner Mongolia, mainly affecting northwest and north China. In the northerly route, dusty weather generally originates in the vast area south of Ulaanbaatar, Mongolia, and mainly affects the eastern part of northwest China, most of north China and southeast China.