延安层状云暖层中水凝物粒子的谱分布

Size Distributions of the Water Drops in the Warm Layer of Stratiform Clouds in Yan'an

分析了2003年9月延安上空机载PMS探测的层状云资料,发现延安层状云暖层中水凝物粒子的谱分布可以用一种形式的分布密度函数来表示。用这种函数拟合小云滴、大云滴和雨滴的谱分布,拟合结果与观测的谱分布较为一致,其特征值相关系数大于0.945,拟合出的平均直径、均方直径、均立方直径以及浓度与观测值也较接近,其相对误差小,拟合谱能表现出谱型特征。

The airborne PMS-detecting data of stratiform clouds in Yan＇an in Sep. , 2003 are analyzed. It is found that one density distribution function can represent the water drops size distribution in the warm layer of stratiform clouds in Yan＇an. The function is used to fit the size distributions of small cloud drops, big cloud drops and raindrops. The fitted spectrum distribution is well matched with the observed one, and the correlation coefficients of their characteristic values are greater than 0.945. The calculated mean diameter, square-root diameter, cubic root diameter and concentration are also close to the observational results and the fitted size distribution is able to reproduce the feature of observed size distribution well.