There will be two more rounds of sand and dust in the north this week. Why is there so much dust this spring?

　　(Economic Observation) North China will encounter two more rounds of sand and dust this week. Why is there so much dust this spring?

　　China News Service, Beijing, April 12 (Reporter Chen Su) According to the latest forecast from the Central Meteorological Observatory, northern China will experience two rounds of sand and dust this week.

This spring, sandstorms in northern China have come in turns. Why are there so many sandstorms?

　　According to forecasts, from the 12th to the 13th, some areas in the southern Xinjiang basin and eastern Xinjiang, central and western Inner Mongolia, western Gansu, northern Ningxia, northern Hebei and other places will have sand or floating dust weather, and the western part of Inner Mongolia and the southern Xinjiang local area There is a sandstorm.

　　Subsequently, from the 14th to the 16th, there will be another sandstorm process from west to east in central and western Inner Mongolia, the eastern part of the northwestern region, the northern part of North China, and the western part of the northeastern region from west to east.

　　Since the beginning of this year, the sand and dust weather affecting China has been obviously stronger.

According to statistics from the China Meteorological Administration, the average number of dust days in the northern region has been 1.5 days this year, the most since 2005. A total of 6 sand and dust weather processes have occurred this year, of which the period from March 13th to 18th is the last ten years. The strongest sandstorm, the north has encountered the "yellow sand all over the sky" that has not been seen for many years, and the PM10 "explosive" in many places. Among them, the PM10 concentration in many areas of Beijing once exceeded 9000 micrograms/m3.

　　At the same time, sand and dust have a wide range of influence.

According to Zhang Juan, a meteorological analyst at China Weather Network, the impact of sand and dust has covered more than 20 provinces. The southernmost boundary once reached the central Hubei-South Anhui-Northern Zhejiang line. Cities such as Shanghai and Hangzhou in the Yangtze River Delta also encountered it. The rare dusty weather.

　　Why is the sand and dust weather strong this year?

　　Ren Guoyu, chief expert of the National Climate Center and part-time professor of China University of Geosciences (Wuhan), told reporters that the intensity of sand and dust weather this year is higher than in previous years, mainly because of the sand and dust source areas in Mongolia and northwest China. The spring rainfall is unusually low, and southern Mongolia and northwest Inner Mongolia are reduced by 100% compared to normal years. Due to the lack of precipitation, the temperature in spring is also relatively high and the climate is abnormally dry.

In this context, coupled with strong winds caused by extratropical cyclones in spring, it is easy to blow up dry soil or dust produced by drought, into the northwestern airflow, and bring it to North China and other places.

　　In addition, Jia Xiaolong, deputy director of the National Climate Center, said that the cold air Siberian High that affects China has increased many times this year, providing very powerful driving conditions for the formation of sand and dust weather. Mongolia, Northwest China, and North China have been affected by phases. The influence of the northwesterly wind is conducive to the transportation of sand and dust from the source to the south-central direction, resulting in a large-scale obvious sand-dust weather process in the northern region.

　　According to statistics from the Meteorological Department, the high incidence of sand and dust weather in China is mainly concentrated from March to May, accounting for almost 80% of the entire year.

Among them, April had the most sand and dust weather process, with an average of 4.3 times.

Cold air activities are expected to be frequent in mid-April, and sand and dust weather needs to be guarded in the northern region.

　　In addition to sand and dust, the north is also affected by haze this spring, and it is rare to see good weather.

　　Xue Jianjun, deputy director of the National Meteorological Center, said that in March 2021, the weather conditions in Beijing-Tianjin-Hebei and surrounding areas deviated by 4.2% from the same period in 2020. The wind speed was low and the relative humidity was high, which was not conducive to the diffusion and dilution of pollutants, and could easily lead to fog and fog. Haze weather.

"In the past, the fog and haze will be improved after the cold air, but in March this year, due to the high temperature in the sand source area, it is easy to get sand, and the cold air brings sand and dust weather. The combination of these factors makes the air quality even worse. it is good."

　　Experts remind that when sand and dust weather strikes, the public should minimize physical exertion and outdoor activities, especially the elderly, infants, pregnant women, the infirm, and patients with respiratory diseases and heart diseases.

Wear masks, glasses, hats and gauze when going out during sandy weather, and stay away from high-rise buildings, billboards, etc.

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