Beijing, 3 Mar (ZXS) -- Since March, there have been four sand and dust weather processes in China, more than the same period of the year, especially the recent sand and dust weather processes affecting the population of 25 million people. In recent years, China has continuously strengthened its environmental protection efforts, and the vegetation coverage rate has increased significantly, and when the vegetation condition improves, it has attracted attention to why it is still attacked by sandstorms every spring.

On March 3, Taiyuan City, Shanxi Province suffered from sand and dust, with poor visibility. On the same day, the Shanxi Provincial Meteorological Observatory issued a blue warning signal of sand and dust. The picture shows Taiyuan Shuangta Park in dusty weather. Photo by China News Agency reporter Wei Liang

According to the statistics of the China Meteorological Administration, China's sand and dust weather activities are more frequent this spring, especially the sand and dust weather process from March 3 to 19, which is the strongest and most extensive process affecting China this year, reaching the level of strong sandstorms, affecting 23 provinces and affecting an area of more than 20.485 million square kilometers.

During the sand and dust weather process, sandstorms occurred in parts of southern Xinjiang, central Gansu, Inner Mongolia, northern Hebei, northern Shanxi, Beijing, western Heilongjiang and other places, and strong sandstorms occurred in southwestern Xinjiang, central and southeastern Inner Mongolia, northern Hebei, Beijing, southwestern Heilongjiang and other places, with a minimum visibility of less than 100~200 meters.

Zhang Bihui, director of the Environmental Meteorological Office of the Central Meteorological Observatory, said in an interview with reporters on the 25th that the intensity of the process reached the level of strong sandstorms, which was the third strongest since March 2000.

In recent years, the vegetation coverage rate in northern China has increased significantly, why is it still difficult to cure the sandy weather?

Ding Ting, a researcher at the Climate Prediction Office of the National Climate Center, said that in recent years, the vegetation in northern China has increased greatly, and the ecological environment has improved significantly, which is generally conducive to gradually reducing the number of sand and dust that invades China. However, the Gobi Desert in southern Mongolia is also an important source of sand and dust affecting China, and the precipitation in Mongolia in the 2022 vegetation growing season is less than that in the same period in the past 20 years, and the vegetation cover in the sand source area is poor, and the bare surface lacks vegetation protection.

"In addition, this year's dust weather is mainly related to the recent anomalies in atmospheric circulation." Ding Ting said that the temperature in the early spring of this year warmed up significantly, especially in early March, there was an extremely rare warming weather, which led to rapid melting of the frozen sand in the early stage. March to April is the windy season in the north. Under certain windy conditions, the sand and dust from the sand source have been transported to China many times, which is the most direct reason for the many serious sand and dust weather this year.

Zhang Bihui said that dust weather is formed by a combination of long-term climate background, geographical background and short-term climate change. From the perspective of China's geographical environment, northern China and neighboring countries and regions have a relatively large area of sand sources, in the congenital conditions of sand sources, combined with climatic factors, especially in the early spring of this year, the temperature is obviously high, conducive to surface thawing, coupled with the effect of ground wind, will be very conducive to sand and dust winching, and under the air flow transportation, a large number of sand and dust particles to the downstream area to transmit settlement.

"In the context of climate warming, the temperature in the early spring of the northern sand source area is high, which is very conducive to the sand soil becoming loose in the sand source area, which increases the possibility of sand and dust weather." Zhang Bihui said.

Looking forward to the trend of sand and dust weather in the later part of this year, Zhang Bihui said that it is expected that in spring (April to May), the precipitation in the sand source areas from southern Mongolia to central and western Inner Mongolia will be less, the temperature will be higher than the same period of the year, and there will be a phased southward influence of Mongolian cyclones, which is conducive to the formation of sand and dust weather. It is estimated that the number of sand and dust processes in northern China is more than the same period in the past decade, and the sand and dust intensity is generally the same as in the past decade.

The Central Meteorological Observatory predicts that from March 3 to April 31, affected by a new round of cold air, there will be a sand and dust weather process from west to east in northwest China, north China, northeast China and other places.

Zhang Bihui said that from April to May, the risk of sand and dust weather in northern China is greater, and it is necessary to pay close attention to the weather forecast, do a good job of protection in time, and reduce the impact of sand and dust weather on transportation, agriculture and animal husbandry, human health and urban operations. (End)