上海地区不同类和不同强度灰霾季节分布特征

主要采用美国宇航局(NASA)2007年1月-2010年11月CALIPSO卫星搭载的正交极化云-气溶胶激光雷达(CALIOP)L1产品及地面气象观测资料,分析得到上海地区干霾和湿霾、不同强度灰霾天气的季节分布特征,并重点研究了发生干霾时气溶胶散射强度、粒子规则性和尺度大小随季节的变化规律。结果表明:灰霾的发生具有较明显的季节性,春季为干霾高发期,其次是夏冬季;夏冬两季轻度以上干霾发生比例均大于春季与秋季;大气中主要以小尺度、较规则的气溶胶粒子为主;干霾时,气溶胶粒子和不同量级色比值所占比例季节变化不大;夏季发生干霾时小尺度粒子所占比例最大。

Seasonal Variation in Haze for Different Types and Intensities at Shanghai

Seasonal variation of haze for different types and intensities at Shanghai were revealed by analyzing the onboard orthogonal polarization cloud-aerosol lidar(CALIOP) L1 products from CALIPSO satellite of National Aeronautics and Space Administration(NASA) and ground meteorological observation from January 2007 to November 2010,with an emphasis on the seasonal variation of aerosol scattering intensity,particle regularity and size during dry haze periods.Results showed that there was an obvious seasonal variation in occurrence of haze,and the incidence of dry haze was the highest in spring,followed by that in summer and winter.Occurrence of haze above mild-intensity dry haze in summer and winter was more frequent than that in spring and autumn.The atmosphere mainly contained relatively irregular and small aerosol particles.During different seasonal dry haze periods,the frequency of magnitudes of aerosol particles and color ratio did not change significantly in seasons.The proportion of small size particles was the largest during summer dry haze periods.