Sand and dust strike again Why is the dust weather so frequent this spring

Beijing, 4 Apr (Xinhua) -- Question: Sand and dust strike again Why is the sand and dust weather so frequent this spring?

Xinhua News Agency reporters Yan Fujing and Huang Yao

Meteorological monitoring data show that on April 4, China began to be affected by sand and dust weather. On the 9th, the influence of sand and dust weather extended to North China, Northeast China and Huanghuai and other places, most of the area was blowing sand or floating dust weather, and there were sandstorms in central and western Inner Mongolia.

"Yellow sand" strikes again, drawing public attention to dusty weather: Is such weather conditions normal? What are the reasons for the frequent sand and dust weather this spring?

According to statistics, more than 7% of China's annual sand and dust weather occurs in spring (March to May), of which the most frequent month is April, followed by March and May.

According to reports, the formation of dust weather needs to meet three main conditions: long-lasting strong winds, dust sources and instability in the lower atmosphere.

Wu Bo, director of the Institute of Desertification of the Chinese Academy of Forestry, analyzed that the main domestic sources of sandstorms in China are concentrated in desert areas such as southern Xinjiang, Gansu Hexi Corridor, and central and western Inner Mongolia, and vegetation restoration in these areas has played a certain role in reducing the amount of dust released in sand source areas and reducing the harm of sandstorms. However, the Gobi Desert in southern Mongolia is also an important source of sand and dust affecting China, and the vegetation growth in southern Mongolia in 2022 is deviated from the average in recent years, and the vegetation cover of the sand and dust source is poor.

"During this period, Mongolia and northern China have less precipitation, and the temperature in the early spring has warmed up significantly, resulting in the melting of the permafrost and loose surface sand, coupled with the high incidence of winds in the northern region in spring, combined with the surface conditions of exposed sand and dust sources, forming frequent sand and dust weather." Wu Bo said.

According to the forecast of the Central Meteorological Observatory, under the combined influence of cold air and Mongolian cyclones, the range of sand and dust weather in the northern region will be further extended from the 10th to the 11th. It is expected that from the 13th to the 14th, affected by cold air and wind, there will be blowing sand or floating dust in the eastern part of the northwest region and northern China. In the future, will there be more and more dust weather in China?

Ding Ting, a researcher at the Climate Prediction Office of the National Climate Center, said that between 2018 and 2022, the total average number of sand and dust storms in northern China was higher than the average from 2013 to 2017. However, from a longer time scale, in the first 21 years of the 10st century, the total number of dust and the number of dust storms are significantly higher than in the past 10 years. This shows that at this stage, China is still in the context of reducing the impact of sand and dust, and it cannot be considered that there is a significant trend of sandstorms.

Data from the State Forestry and Grassland Administration show that China still has 257.37 million square kilometers of desertified land and 168.78 million square kilometers of desertification land, especially large areas of desert and Gobi have always been huge and permanent sources of sand and dust, and sand prevention and control will be a long-term and arduous important task.

Experts said that desertification control is not achieved overnight, and in the future, it is still necessary to strengthen vegetation restoration, reduce the frequency of dust weather and dust storm hazards, and strengthen international cooperation to jointly control the global problem of dust storm damage.

"After the launch of Mongolia's 'Plant One Billion Trees' program, China actively supports and cooperates with Mongolia to carry out desertification prevention and control projects, which can better help the vegetation restoration of overseas sand and dust sources and reduce the harm of sandstorms." Wu Bo said.