Comparative analysis on the boundary layer features of haze processes and cleaning process in Guangzhou
LIAO Bi-ting1, HUANG Jun2, WANG Chun-lin2, WENG Jin-xian1, LI Li-wei1, CAI Huan1, WU Dui3,4
1. Guangzhou Huangpu Meteorology, Guangzhou 510530, China;
2. Climatic Center of Guangdong Province, Guangzhou 510080, China;
3. Jinan University Institute of Mass Spectrometry and Atmospheric Environment, Guangzhou 510630;
4. Guangdong Engineering Research Center for Online Atmospheric Pollution Source Apportionment Mass Spectrometry System, Jinan University, Guangzhou 510630, China
Base on the ground weather data and data of microwave radiometer and wind profile from 2014 to 2016 in Guangzhou national climate observatory, the characteristics of boundary layer structure of the typical during haze processes and cleaning process in Guangzhou are studied. The results are showed as follows:(1) In haze process, the wind speed decreases with height below 270m, but increases with height over 270m, and the increase rate of wind speed below 2000m is lower than that over 2000m. The prevailing wind direction rotates clockwise with height. The wind speed below 510m height is basically less than 3.0m/s, and from 08am to 20pm, the wind speed is less than 2.0m/s below 390m. In cleaning process, there is a speed higher than 5.0m/s zone at 510~1590m and 2790~3000m respectively. Below the height of 1830m, the average wind speed of each layer in the cleaning process is obviously higher than that in haze process. (2) The low temperature inversion was negatively correlated with visibility and positively correlated with concentration of PM2.5, and the correlation coefficients are -0.367 and 0.455respectively. The correlation coefficients is higher when the low temperature inversion and low altitude inversion are simultaneously, and the correlation coefficients are -0.5 and 0.601, respectively. It shows that the existence of multilayer inversion is more prone to haze weather. In haze process, the correlation of low altitude inversion to visibility and PM2.5 was not obvious. In cleaning process, the occurrence of low altitude inversion was mainly related to the cold air coming down from the north, which was positively correlated with visibility (0.217), and negatively correlated with the concentration of PM2.5(-0.64). Low altitude inversion is not conducive to the formation of haze weather. (3) During haze process, the frequency of the low temperature inversion is 60.68%, the average inversion intensity is 1.38℃/100m, and the average inversion layer thickness is 153.2m, which is obviously higher than that of the cleaning process. During cleaning process, the average frequency of occurrence, inversion intensity and inversion layer thickness of low temperature inversion are 64.61%, 0.27℃/100m and 691.07m respectively, which are significantly higher than those of haze process. (4) The mixing layer height of cleaning process is obviously higher than that of the haze process. The daily mixing layer height (958.92m) of cleaning process is 2.4times that of haze process (398.03m).
廖碧婷, 黄俊, 王春林, 翁静娴, 李黎微, 蔡桓, 吴兑. 广州地区灰霾过程和清洁过程的边界层特征对比分析[J]. 中国环境科学, 2018, 38(12): 4432-4443.
LIAO Bi-ting, HUANG Jun, WANG Chun-lin, WENG Jin-xian, LI Li-wei, CAI Huan, WU Dui. Comparative analysis on the boundary layer features of haze processes and cleaning process in Guangzhou. CHINA ENVIRONMENTAL SCIENCECE, 2018, 38(12): 4432-4443.