摘要
利用非静力平衡中尺度数值模式MM5,在四重嵌套网格区域内采用Reisner霰方案,对2009年2月12—13日辽宁雨夹雪转暴雪天气过程进行数值模拟,并对云内微物理过程特别是对雨水、雪和霰的源项进行分析。结果表明:雨水与雪碰并和雨水与云水碰并是产生雨水的主要微物理过程,并且雨水的增长主要分布在700 hPa以下。300—200 hPa之间雪的凝华增长、冰晶向雪的自动转化和900 hPa以下雨水与雪碰并成雪是雪增长主要的物理过程。冰晶向雪的自动转化对降雪的增长和长时间维持起到了重要作用。列出了此次天气过程降水云系的三层云结构及微物理过程模型。
Based on the nonhydrostatic mesoscale model MM5 with the Reisner graupel scheme in four nested domains,the rain and snow becoming heavy snow process on February 12 and 13,2009 was simulated in Liaoning province,and microphysical process within cloud was analyzed,especially the source terms of rain,snow and graupel.The results indicate that the collisions between rain and snow and between rain and cloud water both are the main microphysical process forming rain.The increased rain mainly occurs under 700 hPa.Deposition growth of snow from 300 hPa to 200 hPa,the automatic transformation from ice crystal to snow and the collision between rain and snow under 900 hPa are the mainly microphysical process of increase of snow.The automatic transformation from ice crystal to snow is important to the increase and the maintenance of snowfall.At last,three levels cloud structures and the microphysical model are presented in this process.
出处
《气象与环境学报》
2010年第2期31-39,共9页
Journal of Meteorology and Environment
关键词
雨夹雪转暴雪天气
微物理过程
数值模拟
Rain and snow becoming heavy snow
Microphysical processes
Numerical simulation
