相对湿度和风速对海洋大气气溶胶粒子谱的影响

Effect of relative humidity and wind speed on marine atmospheric aerosol particle size distribution

利用2004年8月～2016年12月期间海上测量的气溶胶数据,研究了海洋大气气溶胶粒子数浓度和粒子谱受气象条件影响的变化规律。气溶胶数据所得地点为广东茂名近海、太平洋以及印度洋海域。数据内容包含两个部分:(1)利用光学粒子计数器(OPC)测得的大气气溶胶的粒子数;(2)由自动气象站等设备测得的大气温度、相对湿度、气压、风速等气象参数。分析了不同气象条件下的粒子谱变化特征,即利用理论模型模拟了不同相对湿度和不同风速条件下粒子谱的变化规律,并将该理论模拟值与与实际测量值进行对比。其结果表明:使用r(RH)/r=(1-RH)^(-(1/3.9))模型来模拟相对湿度对粒子谱的影响比较符合实际,使用lgN=a×U+b模型来模拟风速对粒子谱的影响比较合理,这对于建立海洋大气气溶胶模式有着重要的指导意义。

Based on aerosol data measured at sea from August 2004 to December 2016,the variation of aerosol particle number concentration and particle size distribution dependent on meteorological conditions was studied.Aerosol data were measured in the offshore sea of Maoming,Guangdong as well as the Pacific Ocean and the Indian Ocean.There were two parts included in the data:(1)the particle number of atmospheric aerosol measured by the Optical Particle Counter(OPC);(2)it was measured that atmospheric temperature,relative humidity,air pressure,wind speed and other meteorological parameters by Forain Weather System etc..The variation of particle size distribution on different meteorological conditions was analyzed,i.e.the variation of particle size distribution was simulated under different relative humidity and wind speed following by the value of theoretical analog was compared with that of actual measured.The results show that,on the one hand,it is realistic to retrieve the influence of relative humidity on particle distribution by using the model ofrr(RH)/r=(1-RH)-(1/3.9).On the other hand,it is reasonable to utilize the model of lg N=a×U+b to retrieve the effect of the wind speed on particle size distribution.There is an important guiding significance for the establishment of ocean atmospheric aerosol model.