摘要
针对山西省2009年6月18～19日的一次降水过程,利用机载DMT探测资料、Micaps常规天气资料和卫星云图等资料分析了这次降水的宏微观特征。结果表明:这次降水是锋面云系产生的,18日山西省处于冷锋锋前,19日为冷锋锋后;锋前云底较低,云层较厚,有夹层存在,云中上升气流很强,云滴数浓度最大为280cm-3、平均直径最大为15μm、含水量最大值为0.35g/m3,云滴谱呈双峰或多锋型;锋后云底较高,云层较薄,云滴数浓度最大值为170cm-3、平均直径最大为10μm、含水量最大值为0.05g/m3,云滴谱呈双峰或多锋型;层状云在垂直方向和水平方向均存在不均匀性;垂直方向含水量变化与云滴尺度变化较为一致,水平方向含水量增加主要因为大云滴数密度的增加;Γ分布拟合云滴谱结果接近实际分布。
A precipitation process in Shanxi Province during 18-19 June 2009 is analyzed using data from airborne Droplet Measurement Technologies observations, synoptic charts, and satellite cloud photographs. The results show that the precipitation process can be described as typical cold-front cloud precipitation. In the prefrontal zone on 18 June, the cloud base was low, and thick clouds with a strong updraft existing cloud-free area. The maximum number concentration and maximum mean diameter of the cloud droplets were 280 cm-3 and 15 ~tm, respectively. The maximum cloud liquid water content （LWC） was 0.35 g/m3, and the cloud droplet spectra are mostly bimodal and multimodal. In the post-frontal zone on 19 June, the cloud base was high, and the clouds were thin. The maximum number concentration and maximum mean diameter of cloud droplets were 170 cm-3 and 10 μm, respectively. The maximum cloud LWC was 0.05 g/m3, and the cloud droplet spectra are mostly bimodal and multimodal. The stratiform clouds in the vertical and horizontal direc- tions were inhomogeneous. The diameter of the cloud droplets changed when the LWC changed in the vertical direction,and the LWC in the horizontal direction increased mainly because of the increase in the number density of large cloud droplets. The results off distribution fitting of the cloud droplet spectra were close to the actual distribution.
出处
《气候与环境研究》
CSCD
北大核心
2012年第6期693-703,共11页
Climatic and Environmental Research
基金
中国气象局云雾物理环境重点开放实验室开放科研课题2009002
中国气象局云雾物理重点开放实验室重点开放科研项目2009Z0033
公益性行业(气象)科研专项GYHY201206025
中国气象局业务项目云水资源评估1220200108
关键词
层状云
数浓度
含水量
云滴谱
Stratiforrn cloud, Number concentration, Liquid water content, Cloud droplet spectra
