摘要
通过对2009年4月22日至25日发生在甘肃、宁夏、内蒙古的一次沙尘暴观测和模拟回报试验,分析了沙尘暴过程中水汽及水热的变化特征,检验了天气研究和预报模式(WRF)对沙尘暴过程的模拟能力。结果表明,WRF能较好地再现出沙尘暴过程中水汽变化的基本特征。沙尘暴发生前,地面感热明显增加,大气中水汽明显减少。在沙尘暴过程中,扩散作用和气溶胶的凝结作用影响水汽的变化,而水汽的垂直方向变化较小;高空云水和云冰含量异常偏小,低层大气的温度和水汽含量下降。热力诊断的结果表明,沙尘暴过程中,由于水汽的相变,在600～800hPa高度处,水汽凝结产生的视热源的加热率高达6℃.d-1,表明非绝热加热作用在沙尘暴的维持和发展起着重要的作用。
In this paper,the content of the atmospheric moisture and the heat flux in a dust storm occurred in Gansu,Ningxia and Inner Mongolia during April 22-25,2009,were analyzed with the observed as well as simulated data.The performance of the Weather Research and Forecast（WRF） Model for simulating the changes of little amount elements was also tested.The results showed that the WRF model performed well for estimating the moisture variations in the dust storm process.Before the occurrence of the dust storm,the sensible heat flux above ground surface increased obviously,while the content of the atmospheric moisture fell.In the duration of the dust storm,the atmospheric moisture scattered with the wind and condensed to the aerosol articles in the lower layer;the moisture content did not change much along the altitudinal gradients;the amount of the rain-,snow-,graupel-,and ice-mixing ratio in the high atmosphere was extremely small.The heating scale by the apparent moisture sink reached 6 ℃·d-1 at the 600-800 hPa level due to the moisture condensation in the lower layer.This suggested that the atmospheric diabatic heating could play a critical role in the development of a dust storm.
出处
《中国沙漠》
CSCD
北大核心
2013年第1期205-213,共9页
Journal of Desert Research
基金
国家科技支撑计划项目(2011BAA07B06)
教育部博士点基金项目(20100211110012)
国家自然科学基金项目(41071028)资助
关键词
沙尘暴
WRF模式
大气水汽
视热源
视水汽汇
dust storm
WRF model
moisture
apparent heat source
aparent moisture sink
