China News Service, Beijing, March 16 (Chen Hang) The Beijing Ecological Environment Monitoring Center stated on the 16th that from the night of the 15th to the morning of the 16th, under the action of the northerly wind at the bottom of the high pressure, the main body of sand and dust moved out of Beijing, but southern Hebei The air quality in Shanxi, Shandong, Henan, Anhui and other places is still affected by sand and dust and has reached level 6 serious pollution.
Beginning at noon on the 16th, after Beijing turned to high pressure, the wind direction turned to southwesterly, and foreign sand and dust gradually returned to affect Beijing. The PM10 concentration in the southwestern border area of Beijing began to increase sharply from 14:00.
At present, the backflow of sand and dust has affected the southern western regions such as Mentougou, Fangshan, Fengtai, Haidian, Xicheng, Daxing, etc. In some areas, the hourly PM10 concentration of 5-6 has reached a severe-severe pollution level. The average PM10 concentration of Beijing at 18:00 is 245 micrograms /Cubic meter, level 3 light pollution level.
Zhang Bihui, director of the Environmental Meteorological Center of the China Meteorological Administration, previously stated that the backflow of sand and dust weather was mainly due to the transmission of dust particles downstream under the action of a systematic northerly wind on the 15th, including Hebei, Henan, Shandong and other places. The impact of sand and dust weather.
After the influence of the northerly wind passed on the 16th, it gradually turned into a weak southerly wind, but the dust particles in the downstream area did not completely settle. There are still some dust particles suspended in the air, which will turn into a weak southerly wind tomorrow. Under the circumstances, the sand and dust particles will be transported northward to a certain extent, forming a backflow of sand and dust.
According to the Beijing Municipal Ecological Environment Monitoring Center, it is expected that under the influence of the return of external sand and dust tonight, the primary pollutant in Beijing will be PM10, level 3-4, with a mild to moderate pollution level, and certain areas and periods will reach severe levels- Severe pollution level.
The Meteorological Department said that the sky in Beijing will not be calm in the next few days. Clouds in the sky will increase on the 18th and 19th, and the temperature will be relatively low, with a maximum of 11-13°C. The light rain on the night of the 19th will bring some moisture to the dry land.
The northerly winds at level 4 or so on 20-21 will bring a clear and clear blue sky. Sunlight prevails. Although the daytime temperature can reach 16-13°C, there is a wind chill effect.
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