Beijing to improve air pollution warning level why the pollution so serious – Sohu news denka

Beijing to improve air pollution warning level why the pollution so serious? Sohu news Beijing News News (reporter Wang Shuo) haze pollution, upgrade. Today, 15:30, Beijing heavy air pollution emergency headquarters office will be raised to the level of early warning yellow warning. It is understood that this is the second time since the fall of Beijing issued a yellow warning of heavy pollution, a start yellow police in October 2nd. The current pollution at what level? The Beijing Municipal Environmental Monitoring Center Engineer Wang Zhanshan introduction, 13 days before and after the evening, the air quality in Beijing fell 5 heavy pollution, as of 14 PM, the city is still in heavy pollution. Among them, the highest level in PM2.5 concentration, close to 350 micrograms per cubic meter, has reached 6 serious pollution levels, other areas are more than 200 micrograms per cubic meter, even the lowest concentration of Yanqing in 160 micrograms cubic meters (more than 150 micrograms per cubic meter for severe pollution). Prior to the pre judgment, the pollution process is relatively serious period is 13, 14, the level of pollution is only a moderate level of 4. However, starting from the evening of 13, Beijing has entered the severe pollution of the grade 5, 14, the city is to reach serious pollution level of 6. Why is the actual concentration so high, Wang Zhanshan said that this is mainly weak cold air is much weaker than expected, in the process did not play a clear role in pollution accumulation. Wang Zhanshan also said that in the process of pollution, the overall concentration of Beijing is higher than the surrounding provinces, which is the result of the Beijing special terrain and the weather system. On the one hand, southerly winds, pollutants in the southern region of Beijing to blow, on the other hand is a dustpan shaped terrain of Beijing, surrounded by mountains on three sides, contaminants from the South "dustpan" after entering Beijing, Taihang Mountain, the Yanshan mountains block, in the Beijing area of accumulation, therefore, the pollutant concentration is higher than the surrounding Beijing. Heating has not yet started, why is there such a serious pollution, said Wang Zhanshan, mainly affected by adverse weather conditions. The wind speed is low, the level of diffusion conditions; secondly, the lower boundary layer, the vertical diffusion limited space, "the normal time Beijing boundary layer over 1.5 kilometers, but only 300 to 500 meters, the equivalent of" hat under pressure "to the pollutants also scattered out". In addition, the recent air humidity in Beijing, 14 am, Beijing near the surface of the air relative humidity is close to saturation, is conducive to the accumulation of pollutants, and produce a chemical reaction of the two generation PM2.5.相关的主题文章: