Three major meteorological conditions created the strongest sandstorm in a decade

A strong sandstorm swept across most parts of northern China, causing the strongest and most extensive sandstorm process in China in the past 10 years. During the interview, experts told that the powerful cyclone in Mongolia lifted the local sand and dust to high altitude, and then, under the effect of the continuous eastward movement to the south, a large amount of sand and dust drove straight in and transported them to many parts of China. Several weather conditions worked together to finally form the strongest sandstorm in China in the past 10 years. Experts also emphasized that the sand prevention and control projects that China has promoted for many years have played a certain role in reducing sand and dust storms, and that the fundamental reduction of sand and dust weather lies in the source of governance.

Experts interpret the cause of the strongest sandstorm in the past decade

Wang Gengchen, a researcher at the Institute of Atmospheric Physics of the Chinese Academy of Sciences, said in an interview with a reporterthat three conditions must be met for the formation of a dust storm: sand source, cyclone and advection.

The sand and dust weather affected 12 provinces and cities in northern China from west to east. The Central Meteorological Observatory upgraded the sand and dust storm warning from blue to yellow on the 15th. The State Forestry Administration released information on the 15th. Based on a comprehensive assessment of satellite imagery and ground monitoring information, the dust originated in southwestern Mongolia and then moved south with the airflow. It entered at the junction of Mongolia and the central and western parts of Inner Mongolia on the evening of the 14th Within China.

According to information from a press conference held by the General Administration of Emergency Situations of Mongolia on March 15th, on the evening of the 14th, severe weather such as snowstorms and strong sandstorms occurred in Kent and other provinces of Mongolia. The wind speed reached 20 meters per second and gusts reached 30 per second. Meters to 34 meters. Wang Gengchen said that the local blizzards and windy weather in Mongolia are a manifestation of the strong Mongolian cyclone. The Central Meteorological Observatory indicated that the Mongolian cyclone was developing strongly, and the central pressure reached 980 hPa at 02:00 on the 15th. It is precisely because of the powerful cyclone that a large amount of sand and dust in Mongolia has been drawn into the high altitude. Wang Gengchen analyzed that the strong cyclone not only means that the amount of dust involved is increasing, but the height of the dust being lifted into the air is at least 10 kilometers.

“Without a cyclone, sand and dust cannot be taken to high altitudes, but can only move on the surface; but if there is no continuous high air flow, sand and dust will not be transported over long distances and will settle quickly. The higher the dust rises, It will blow farther.” Wang Gengchen said that the sand and dust involved in the high altitude encountered continuous cold and high pressure moving eastward and southward, eventually transporting the dust to Beijing and other places.

Expert: Doesn’t mean that this intensity of sandstorm weather will happen every year

Wang Gengchen said that the source of China’s sand and dust weather is located in the north, northwest and western regions, involving Mongolia, Central Asian countries, and China’s Inner Mongolia and Xinjiang. However, Central Asia and Xinjiang are far from the eastern region, and the national defense and sand-fixing work between Canada and China is effective. Therefore, the sand and dust from the west will hardly affect the eastern region. On the contrary, because of the close distance, the dust from Inner Mongolia or Mongolia can still spread to eastern China. Chen Guangting, a researcher at the Cold and Arid Regions Environmental and Engineering Research Institute of the Chinese Academy of Sciences, told in an interview that according to statistics, about half of the sand and dust weather in China came from Mongolia.

Wang Gengchen said that China has not experienced such a wide and intense sandstorm in 10 years. The dust storm is the result of several meteorological conditions. But this does not mean that these several meteorological conditions work together to be a normal state, nor does it mean that this kind of sandstorm weather occurs every year. Ren Guoyu, chief expert on climate change at the China National Climate Center, “China’s western regions such as Xinjiang and Inner Mongolia, as well as some areas in Mongolia, are sources of sand and dust. In the long term, precipitation in these regions It has been increasing, but the short-term situation is difficult to say, because some years will also encounter winter and spring droughts, which may cause sandstorms to reappear. For example, from 2000 to 2002, there were several very strong sandstorms. .”

Is the sandstorm related to the “protective forest opening”?

Northern China has experienced the strongest sand and dust weather that has not been seen in 10 years. What is the role of China’s ongoing sand prevention and control projects in resisting sandstorms? Wang Gengchen believes that the desertification prevention and control project still plays a role in weakening the dust storm. He said that China’s continuous advancement of sand control projects has made the frequency of encountering sand and dust weather less and less in recent years. “Nowadays, people rarely see sandstorms, and sometimes they only see the floating dust weather that occurs in spring. These are all manifestations of the role of China’s sand control and sand fixation projects.”

Ren Guoyu also holds this view. He said that many shelter forests have been built in northern China. For example, the “Three North” shelter forests have carried out ecological civilization construction and ecological restoration, and the vegetation of the Loess Plateau is also growing. “This year’s sandstorm is mainly a natural phenomenon. China is working hard. The construction of shelter forests has achieved obvious results. In recent years, the situation has actually improved, and the frequency of sandstorms has been much less than that of earlier times. Whether it is on the scale of millennia or decades, it is decreasing. ”

But he also analyzed that this kind of improvement of surface vegetation is still limited to a small area, a large area is still in a semi-arid area, and the desert area is still very large. He said that the effect of the shelterbelt is to reduce the amount of local sand and dust in the shelterbelt area, which has an inhibitory effect on the local blowing sand. However, there will still be “sand” in places where afforestation is not possible, such as deserts and Gobi. If the material in the dusty weather is not from the local area, but from the sand and dust transported from a distance, it is difficult to achieve good results.

Some netizens speculated that it was because the shelter forest opened the mouth, blowing away the smog and ushering in a sandstorm. In this regard, Zhang Bihui, director of the Environmental Meteorological Center of the China Meteorological Administration, said on the 15th that the shelter forest is mainly some changes in the surface vegetation near the ground, and its impact on the entire wind field is very limited, and for this very strong weather process, The impact of the shelterbelt is also very low compared to the intensity of this kind of weather, and can basically be ignored.

Chen Guangting told the reporter that through research, it was found that the control of sand and dust weather only relying on partial control will not achieve fundamental results. Because the research results show that half of the source of sand and dust weather is imported from abroad. Therefore, the fundamental problem of preventing sand and dust weather lies in solving the problem of sand sources, which involves cooperation in global environmental governance, rather than relying on China’s sand control and sand prevention projects. Chen Guangting said, “It’s not that we manage our own place by ourselves, so we won’t be affected by sandstorms.”

Ren Guoyu said that after all, shelterbelts are not a controlling factor. The real controlling factor is still nature. “God does not give face, mainly because of human activities.” Wang Gengchen also said that reducing the occurrence of sand and dust weather lies at the source of governance.