广州地区灰霾与清洁天气变化特征及影响因素分析

利用2006~2010年广州气象站逐时地面风场、湿度、能见度观测资料和2006~2009年珠江三角洲其他33个地面观测站风场观测资料,通过对灰霾与清洁天气过程的风速风向进行统计分析与矢量和分析,研究了广州地区灰霾与清洁天气过程的变化特征及影响因素.结果表明:灰霾天气过程在干季发生较频繁,主导风向为东南及东南偏南风,风速一般在1.5m/s以下,静风频率大于多年静风频率;灰霾天气过程风矢量和较小,扩散条件较差.清洁天气过程主要出现在湿季,风速普遍较大且主导风为东南及东南偏南风,干季也可以出现清洁天气过程,主要为较强的北风及偏北风;清洁天气过程风矢量和较大,有较强的平流输送.

Characteristics and influence factors study of haze and cleaning weather over Guangzhou Area

Based on the hourly wind,relativity humidity and visibility data from Guangzhou meteorological station during 2006 to 2010 and hourly wind data from other 33 meteorological stations over the Pearl River Delta during 2006 to 2009,variation characteristics and influence factors in haze and cleaning weather were analyzed over Guangzhou area by using statistically analysis and Vector Sum Technique(VST) of wind.It was found that,the haze weather occurred frequently in dry season over Guangzhou area.When the haze weather happened,the prevailing wind was SE to SSE,the wind speed was lower than 1.5m/s,and calm winds appeared frequently.In haze weather,the VST of wind speed was comparatively small,the air pollutants accumulated because of the worse diffusion conditions.The cleaning weather most occurred in wet season,the wind speed was relatively large and the prevailing wind was SE to SSE.Sometimes the cleaning weather happened in dry season when the N to NE wind was stronger.In cleaning weather,the VST of wind speed was comparatively large;there existed strong advection transportation of air pollutants.