Study on the Haze Process in Huainan City From October 2019 to March 2020 Observed by Raman-Mie Aerosol Lidar
ZHANG Shuai1, WANG Ming1, SHI Qi-bing1, YE Cong-lei1, LIU Dong2
1. Hefei CAS GBo-Qua. Science and Technology Co., Ltd., Hefei 230088, China
2. Key Laboratory of Atmospheric Optics, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, China
Abstract：The Raman-Mie Aerosol Lidar (RMAL) has advantages over traditional Mie scattering Lidar in accurately measuring aerosol extinction coefficient without assuming radar ratios. The results of the outfield sounding comparison experiment in Hefei indicated that the extinction coefficient retrieved by RMAL below 2.5 km is more accurate than the traditional Mie scattering Lidar with a difference of up to 0.04 km-1, obtained water vapor mixing ratio profiles were consistent well with the sounding. This study presented the long-time observational results of aerosol extinction coefficient and height of atmospheric boundary layer (ABL) data over Huainan City during the autumn and winter from 2019 to 2020 using this technology for the first time. The pollution types (local pollution discharge, transmission pollution, transmission pollution and local pollution accumulation) and spatial-temporal changes of aerosol during the air quality pollution period were analyzed and discussed. The results showed that Huainan City is affected by 20 fine particle air pollution and 8 times dust air pollution during this period. The transportation of dust mainly came from the northwest, and it generally sunk from high altitude to the ground, with a thickness of more than 2 km. The average height of ABL was more than 1.23 km. In the typical fine particle transportation process, the height of the ABL was maintained at about 1.1~1.2 km, and the ground wind direction was mainly northwest, with a small amount of southeast. In the coincidence pollution process of fine particle transmission and local accumulation, the height of ABL was slightly lower (the average height is about 1.0 km), the near-surface wind direction is dominated by northerly winds. The lower edge height of the polluted air masses continued to decrease from low altitude and eventually coupled with near-ground pollution. In the process of heavy pollution caused by fine particles, the evolution trend of surface water vapor mixing ratio, relative humidity and PM2.5 concentration were in good agreement. This showed that increasing moisture absorption of particulate matter and secondary transformation of gaseous pollutants might promote the second generation process of PM2.5. In particular, the trend of atmospheric boundary layer height was closely related to the settlement of polluted air masses and the accumulation of surface pollution. During the attention period, most of the city’s hourly height of ABL was distributed below 1.6 km, with an average of around 1.0 km. When the hourly air quality reached severe pollution, the height of the boundary layer was generally less than 0.6 km. According to the simulation results of the backward trajectory of the air mass, the polluted air mass mainly came from the northerly direction, with a small amount came from the southeast, during the air pollution period of the city with moderate or above pollution. Therefore, it is necessary to strengthen the management and control of pollution sources in the north of the urban area to prevent superimposed effects.
张 帅，王 明，施奇兵，叶丛雷，刘 东. 2019年—2020年秋、冬季淮南市灰霾过程拉曼-米气溶胶雷达观测研究[J]. 光谱学与光谱分析, 2021, 41(08): 2484-2490.
ZHANG Shuai, WANG Ming, SHI Qi-bing, YE Cong-lei, LIU Dong. Study on the Haze Process in Huainan City From October 2019 to March 2020 Observed by Raman-Mie Aerosol Lidar. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2021, 41(08): 2484-2490.
