华东地区夏季云微物理结构的飞机观测分析

Aircraft measurements of microphysical properties of clouds over eastern China in summer

利用飞机搭载云粒子探头对2014年8月12-28日华东地区云的空间分布特征进行了探测,分析了云的垂直结构和水平分布特征,结合同时探测的气溶胶数据,探讨了云与气溶胶的相互作用关系。探测结果表明,安徽地区层状云云滴平均数浓度在24~297 cm^-3,液态含水量在0.04~0.13 g·m^-3,云滴数浓度随云底高度升高而减小,云滴粒径则随云底升高而增大。层积云(Sc)和雨层云(Ns)的云滴数浓度在云底最高,随高度上升浓度下降,液态含水量在云中部最高,云顶和云底处较低,高层云(As)云滴数浓度和液态含水量峰值均出现在云中上部。云的水平分布不均匀,云粒子双峰分布区域对应液态含水量高值区。Ns对气溶胶清除作用明显,清除方式以活化清除为主、碰并清除为辅。

A set of aircraft measurements during August 12 to 28,2014 over Anhui Province were conducted to investigate the cloud spatial distribution characteristics over eastern China,the vertical and horizontal distributions of clouds,and the interactions between aerosol and clouds.The results show that the cloud drops concentration were in the range of 24-297 cm^-3 and liquid water content was 0.04-0.13 g·m^-3.The cloud drops concentration decreased with cloud base height,while cloud mean diameter increased with the cloud base height.Cloud drops were concentrated in the bottom of stratocumulus(Sc)and nimbostratus(Ns),and the cloud drops concentration decreased with the altitude.The liquid water content increased first in Sc and Ns,and then decreased with the altitude.The peak of liquid water content was in the middle of cloud.In altostratus(As),the peak of cloud drops concentration and liquid water content were both in the middle.The horizontal distribution of clouds changed a lot.High liquid water content appeared at the bi-model part of the cloud distribution.Aerosol removal process was obvious in Ns.The cloud activation process removed a large number of aerosol particles and the coagulation process removed a small amount of aerosol as well.