摘要
利用常规气象观测站、地面自动站、温度廓线仪和多普勒天气雷达等资料分析2012年12月13—14日济南地区一次雨—雨夹雪—雪—雨降水过程的降水相态复杂变化的成因。结果表明:济南地区此次降水过程是由江淮气旋的影响发生的,冷空气较弱是降水相态发生二次转换的主要原因。弱冷空气入侵导致近地面层气温降低,降水相态由雨转为雪;随着西南涡和江淮气旋北上,近地面层气温略上升,降水相态又由雪转为雨。近地面层先降温后升温,导致雨雪相态的二次转换;这种温度变化与近地面弱冷空气强度的变化有关。对于此次降水过程,1000 h Pa至地面层温度和0℃层亮带的高度均可作为判断降水相态的判据,位势厚度对降水有一定的指示意义,且对雨转雪过程比雪转雨过程的指示意义明显。
Using the meteorological observation data from weather stations and automatic stations, temperature profiler data and Doppler radar data, forming reasons for phase changes in precipitation for a rain-sleet-snow-rain complex weather process on December 13 to 14,2012 in Ji＇nan were analyzed. The results indicate that this process was affected by Jianghuai cyclone, and weak cold air is the main reason for precipitation phase undergoing twice conversion. The weak cold air invasion makes the near surface layer temperature decreased, so rain turns to snow. With southwest vortex and Jianghuai cyclone moving northward, the near surface layer temperature rises slightly, and snow turns to rain. The near surface layer temperature decreases firstly and then increases, which leads to the twice conversion in precipitation phase. The above temperature variation has a certain relationship with intensity of weak cold air near the surface. In this precipitation process, temperature from 1000 hPa to surface and the height of 0 ℃ level bright band both can be used as criterions of precipitation phase. Geopotentiai thickness has indicative significance to precipitation, and it is more significant for rain turning to snow than snow turning to rain.
出处
《气象与环境学报》
2015年第4期14-19,共6页
Journal of Meteorology and Environment
基金
国家自然科学基金(41175044)
中国气象局关键技术集成与应用项目(CMAGJ2015M34)
山东省气象局重点课题(2013sdqxz02)共同资助
关键词
降水相态
二次转换
天气系统
温度垂直分布
Precipitation phase
Twice conversion
Weather system
Vertical distribution of temperature
