广州地区典型清洁与污染过程的大气湍流与物质交换特征

Turbulence and mass exchange characteristics of typical clean and pollution process over Guangzhou region

利用2004年5月至2005年8月在广州番禺观测的一套陆气相互作用资料，结合污染物浓度资料分析广州地区污染过程与清洁过程的湍流交换特征，重点分析了近地层稳定度、风、湍流能量、物质通量与污染物的关系．分析表明平均风速与平均湍流能量的相关系数高达0．9以上，风速越大湍流能量也越大；污染物浓度与平均风速、湍流能量的相关性较高，其次是与水汽通量，均呈显著的负相关关系．污染过程期间平均风速、湍流能量与水汽通量仅为清洁过程的0．48、0．59、0．51倍，不利于污染物平流与扩散的气象条件降低一半，导致污染物的累积可达3-6倍．污染过程期间污染物之间存在较好的相关，尤其是PM10与NO2之间的相关性较高；而在清洁过程期间，污染物之间的相关性显著下降，PM10与NO2之间的相关性很低．

The turbulent exchange characteristics ofpollntion and clean process over Guangzhou region were analyzed by combining pollutants data with land-air interaction data observed in the period from May 2004 to August 2005. The analysis focused on the relationship between the surface stability, wind, turbulent energy, and mass flux with the pollutants. The correlation coefficient between mean wind and mean turbulent energy reached up to 0.9; And the stronger the wind speed was, the larger the turbulent energy was. The correlation coefficients between pollutants and mean wind, mean turbulent energy were higher, followed by the correlation coefficient between pollutants and vapor flux; the above relationships were in obvious anti-correlations. The mean wind speed, turbulent energy and vapor flux in the polluting process were just 0.48,0.59,0.51 times as high as those with clean process, indicating that the reduction of unfavourable meteorological condition for the advection and diffusion of pollutants by half could result in the pollutants being accumulated by up to 3-6 times. The relationships among the pollutants are better in the pollution processes, especially the relativity between PM10 and NO2 is higher compared with that in the clean processes, in which the relationships among the pollutants were obvious weaker and the relativity between PM10 and NO2 was very low.