Does the smog in Beijing have anything to do with the terrain?

? In the past few days, Beijing has been shrouded in severe fog and haze. The Beijing Meteorological Bureau announced that meteorol

Does the smog in Beijing have anything to do with the terrain?

? In the past few days, Beijing has been shrouded in severe fog and haze. The Beijing Meteorological Bureau announced that meteorological factors such as zonal circulation, static stability and high humidity, coupled with the "dustpan" terrain surrounded by mountains on three sides, have led to the continuous accumulation of pollutants in this area, which has become the external cause of the recent large-scale persistent smog.

Qiao Lin, director of Beijing Meteorological Observatory and director of Beijing-Tianjin-Hebei Environmental Meteorological Center, said that unfavorable meteorological external factors such as zonal circulation, quietness and high humidity "gathered together" and contributed to the persistence of fog and haze.

Firstly, the circulation situation promotes the maintenance and development of fog and haze. The persistent fog and haze weather in Beijing is closely related to the background of large-scale circulation. From 20 16, 16 to 2 1, from 20 16, 12, 30 to 20 17, zonal circulation is dominant in middle and high latitudes in China, among which

Second, static conditions are conducive to the maintenance and enhancement of fog and haze. From February 30th, 20 16 to June 4th, 20 17, Beijing was in the "high pressure rear", the atmosphere remained static, the middle layer recovered obviously, and the ground temperature was high during the day, which was beneficial to the vertical diffusion of pollutants. At night, the ground radiation obviously cools down, forming an "inversion temperature", which is very unfavorable to the vertical diffusion of pollutants and the visibility becomes worse. During the day on the 5th, due to the influence of easterly winds at the lower level, light snow or sporadic light snow appeared in most parts of Beijing, but the effect of fog and haze removal was limited.

Third, high humidity is beneficial to the hygroscopic growth of particulate matter. From 20 1 7,65438+10,1in the morning, the humidity in the lower atmosphere is close to saturation, and foggy weather appears in the plain, with strong fog in some areas, and the minimum visibility is less than 200 meters. Following last year's 65438+February 20th, the "rime" weather appeared again in Fangshan, Daxing and Tongzhou.

In addition, Qiao Lin pointed out that Beijing's special terrain is objectively conducive to the maintenance of fog and haze. Beijing is surrounded by mountains on three sides, and the weak cold air in the west and north is not easy to enter the plain area. The intensity of cold air weakens after passing through the mountains, while the foreign pollutants in the south of Beijing can drive straight in. Fog and haze in Beijing are the most serious in the south and slightly lighter in the north. Affected by the piedmont terrain convergence line of Taihang Mountain, the piedmont areas in southern Beijing and central and southern Hebei formed a heavily polluted area.

The above information comes from xinhuanet.