气溶胶在华北地区霾期间中低对流层中随高度的季节变化

Seasonally vertical distribution of aerosols in middle and low troposphere in north China during haze periods

采用美国宇航局(NASA)的CALIPSO星载正交极化云-气溶胶激光雷达(CALIOP)的监测数据,对2007年1月1日至2008年12月31日华北地区霾期间中低对流层气溶胶散射强度、粒子规则性和粒径大小随高度的季节变化进行了研究。结果表明:霾期间在4 km以下的中低对流层大气中,春季气溶胶粒子的出现频率最高,且散射最强的气溶胶出现高度春季和秋季在1~2 km,夏季在3~4 km,冬季在0~1 km;四个季节均以球形或接近球形的规则性气溶胶为主,其中夏季气溶胶的规则性最强,春季气溶胶的不规则性最强,除春季外气溶胶的规则性随高度的增大而增大;春季气溶胶粒径大于其他季节,且随高度增大而增大,其他季节气溶胶粒径大致随高度增大而减小。多数情况下各层均以小粒径气溶胶为主。

Based on the radar data from January 1st,2007 to December 31 st,2008 from CALIPSO satellite of National Aeronautics and Space Administration( NASA),seasonally vertical distribution of changes scattering intensity,particle regularity and size of aerosols in the middle and low troposphere during the haze periods in the northern China were analyzed. Results showed that,during the haze periods,for the middle and low troposphere below 4 km,the occurrence frequency of aerosol particles is highest in spring,while he strongest scattering intensity of aerosols is at the height of 1- 2 km in spring and autumn,3- 4 km in summer and 0- 1 km in winter.The main aerosol constituents were regular aerosols with spherical or nearly spherical shape. The proportion of regular aerosols is the greatest in summer,and the proportion of irregular aerosols is the greatest in spring. The higher the altitude is,the more regular the aerosols are. The particle size of aerosols is the largest in spring among all seasons. And in spring,along with the increase of height,the particle size of aerosols increases,opposite to theother seasons. The main aerosol constituents are small aerosols for almost all heights.