Prediction of cloud droplet number in a general circulation model
Prediction of cloud droplet number in a general circulation model
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DOI：
10.1029/97jd01810
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发表时间：
1997-09-27
影响因子：
4.4
通讯作者：
AbdulRazzak, K
中科院分区：
文献类型：
--
作者：
Ghan, SJ;Leung, LR;AbdulRazzak, K
液滴数量的预测处理适用于单柱云模型和全球环流模型。液滴数量是根据液滴数量平衡来预测的，该平衡考虑了由于液滴自动转化为雨以及雨、冰和雪的收集而导致的液滴成核、混合和液滴损失。液滴成核根据对数正态气溶胶尺寸分布的参数和每个网格单元内垂直速度的高斯概率分布来参数化。发现预测的液滴数量明显少于观测值，除非垂直分辨率在行星边界层内提供至少 10 个级别。当仅根据成核数量诊断液滴数量时，发现液滴浓度始终高于预测治疗。发现预测的液滴数浓度与气溶胶数浓度呈非线性关系。
A predictive treatment of droplet number is applied to both a single-column cloud model and a global circulation model. Droplet number is predicted from the droplet number balance, which accounts for droplet nucleation, mixing, and droplet loss due to autoconversion of droplets to rain and collection by rain, ice, and snow. Droplet nucleation is parameterized in terms of the parameters of a lognormal aerosol size distribution and in terms of a Gaussian probability distribution of vertical velocity within each grid cell. The predicted droplet number is found to be significantly less than observations unless vertical resolution provides at least 10 levels within the planetary boundary layer. When droplet number is simply diagnosed from the number nucleated, droplet concentrations are found to be consistently greater than with the predictive treatment. Predicted droplet number concentrations are found to be nonlinearly related to aerosol number concentration.