- Overview
The atmospheric boundary layer is the main area of frequent atmospheric pollution. In order to explore the vertical distribution of atmospheric pollutants and change law, in China's tallest building ——pudong Shanghai center building of different height, including PM2.5, O3, CO and NOx, a variety of pollutants concentration and meteorological elements of long-term continuous online monitoring, for regional atmospheric pollution cause analysis, early warning and prevention and control to provide important basis data and analysis basis.
On May 10,2022, particulate vertical profile box figure, for example, can be clearly found above the concentration of particulate matter is significantly higher than near the ground (about 2 times near the ground) and stable decrease with the height of the drop, this is a typical regional transmission characteristics, shows that high pollution air mass due to fast wind speed and early arrived over the city.
On the contrary, in most nights, the surface is not easy to spread to the high altitude through turbulence, so the concentration near the ground is low. For example, by analyzing the vertical profile box diagram of PM2.5 concentration on May 2,2nd, 2022, it is found that the concentration of particulate matter decreases significantly with the height and the cleanliness is high. Meanwhile, the height of the boundary layer at night from 410 m at 0 points to about 200 m at 5 points.
O3 concentrations at different heights exhibit characteristic characteristics with increasing height.
Higher-altitude solar radiation, more sufficient photochemical reaction, and more O3 storage in the residual layer at night, lead to the higher concentration of O3 in the top layer.
More NO emitted near the ground (30 m) consumes O3, resulting in a reduction in the amount of NO transported upward from the ground, less NO and O3 accumulation at higher heights.
The exchange between the stratosphere and the troposphere transmits part of the stratosphere O3 downward, leading to an increased O3 concentration in the troposphere.
