东南沿海地区相对湿度对气溶胶消光特性的影响

Aerosol extinction characteristics in haze and fine weather in southeast coastal area of China

采用能见度仪和温度脉动仪在我国东南沿海典型地区进行能见度和相对湿度测量实验,利用能见度与消光系数和波长的关系,分析了在雾霾和晴好两种天气条件下相对湿度对沿海气溶胶系统消光系数的影响.研究结果表明：对于波长为1.06μm 的激光,该地区两种天气下气溶胶粒子的潮解点均为80%左右;当相对湿度在80%～90%时,随着相对湿度增大,两种天气下消光系数相对干粒子时的增长率基本相同,吸湿增长因子主要介于1～2;当相对湿度大于90%时,二者相对增长差别很大,晴好天气下吸湿增长因子增大了两个量级,远大于雾霾天气.

The extinction characteristics of aerosol have great influence on the effective transmission of laser propagating in atmosphere. In recent years, with the declining of air quality, the aerosol pollution is becoming serious. In order to analyze the dependence of extinction coefficient on ambient relative humidity （RH） under two cases of weather in coastal area, visibility, as well as relative humidity in the southeast coastal area of China is measured by experiments. The results show that the deliques cence points of aerosol particles under the two kinds of weather are both about 80%, and that after deliquescence, the extinction coefficient increases with the increasing of relative humidity. For the laser with a wavelength of 1.06μm, an order of difference of magnitude for extinction coefficient of haze and fine weather is obtained. However, when 80〈RH〈90%, relative increasing of the aerosol extinction coefficient under two conditions is similar, the f（RH） ranging from 1 to 2 mostly： for RH〉90%, the difference is very large. The f（RH） increases by two orders of magnitude in good weather, which is of significance on laser prop agation in the atmosphere.