Recently, the Bulletin of the American Meteorological Society online published the latest research by Professor Wang Kaicun task force of Beijing Normal University entitled "PM2.5 Pollution in China and How It Has Been Exacerbated by Terrain and Meteorological Conditions". Wang Kai-cun Professor is the author of the communication. This study presents a quantitative assessment of the static and stable weather index which is not conducive to the diffusion of air pollutants. It is pointed out that the interaction between the topographic features of the west high and the east low and the meteorological conditions makes the probability of static stable weather higher and higher, which aggravates the degree of air pollution in China.
High-intensity pollutant emissions is the culprit of air pollution outbreaks, and adverse weather conditions are indispensable external conditions to stimulate air pollution. Based on the factors such as near-surface wind speed, height of atmospheric mixed layer and precipitation, this paper evaluates the horizontal and vertical diffusion and wet removal ability of pollutants in the atmosphere, and puts forward the quantitative index to measure the static and stable weather. The index takes into account the influence of topographic features of west high and east low of our country on near-surface wind field, explained the not applicability of the US National Oceanic and Atmospheric Administration (NOAA) in China's static and stable weather index in China. The study found that the probability of occurrence of static and stable events in autumn and winter in China is obviously higher than that in Europe and the United States. The probability of static and stable weather in the autumn and winter of Beijing-Tianjin-Hebei region is 35-42% (20-24% in Europe and the United States), while the stable weather time in the Sichuan Basin up to 50%, adverse atmospheric diffusion conditions combined with high-intensity pollution emissions in China's autumn and winter is the main reason of serious air pollution process frequently happen in our country. Even if the current pollutant emission intensity remains unchanged, with the same atmospheric diffusion conditions in Europe and the United States, China's 82% region's PM2.5 average concentration will be significantly reduced, of which Beijing-Tianjin-Hebei and Sichuan region can reduce the average 12%. The study further points out that due to the current PM2.5 annual average concentration in China is relative high, to achieve the goal of good air days needs to take into account the steady economic growth and more stringent and effective emission reduction measures comprehensively. In the process of developing future emission reduction measures, the influence of meteorological conditions on air quality should not be ignored.
American Meteorological Society catalog only accepts arranged manuscripts, publish 100-150 papers each year, the journal 5-year impact factor is 10.76. The first author of the paper is Professor Wang Kai-chun's doctoral student Wang Xiaoyan (graduated, is now at Fudan University engaged in postdoctoral research), this is the second time that Wang Kaicun research group published paper in this journal.
The paper has been funded by the National Science Fund for Distinguished Young Scholars (41525018).
The paper links: http://journals.ametsoc.org/doi/abs/10.1175/BAMS-D-16-0301.1
(Institute for Global Change and Earth System Science)