热带中尺度海岛地区典型环境污染过程研究

Research of a Typical Environmental Pollution Process About the Tropical Mesoscale Island

使用气象及环境监测资料,对2008年9月12日—19日海南岛海口市一次典型环境污染过程的大气中污染物浓度时空变化、大气背景场和物理量场及其相关因素进行了诊断分析.结果表明:大陆高压前部滞留的高压脊、印缅低压槽是影响海口市环境空气质量的主要天气型,空气污染物浓度的谷峰变化形成的环境污染过程与这2个系统的相继影响有较好的对应关系;高压脊上空持续的下沉气流及边界层低层流场辐合形成污染物汇聚带,导致污染物逐日积累并达到峰值;热带地区发展的热带气旋外围常形成深厚的下沉气流,有利于高压脊区日均污染物浓度增大;印缅低压槽及其偏南风、明显降水有利于污染物的清除.因此,热带地区大型高压脊天气系统及其控制下的海口市地方性流场汇聚是造成地区API(air pollution index)积累及峰值形成的主要原因.

Using meteorological and environmental monitoring data, a typical environmental pollution process was diagnostic analyzed from viewpoints of temporal and spatial variation of pollutant concentration, atmospheric background field, physical field and other relevant factors from September 12 to 19 in 2008 in Haikou, Hainan. Results show that the continental anticyclone ridge and Indian trough are the main synoptic situation which affects the atmospheric environmental quality in Haikou; its alternating evolution corresponds to environment process caused by pollutant concentration change from the peak and trough. Continuous downdraft caused by continental anticyclone ridge and pollutants convergence zone in boundary layer lead to pollutant accumulating to the peak; at the same time, deep downdraft caused by tropical cyclone periphery contributes to the pollutant concentration accumulating. Moreover, Indian and Burma trough, southerly winds and significant rain are conductive to clear the atmosphere pollutants. Therefore, a high pressure ridge in tropical region and the local flow convergence in Haikou are the main reasons for the pollutant accumulation to peak.