污染大气对冻雨过程影响的数值模拟

摘要

To reveal the influence of polluted aerosol on severe freezing weather,especially the freezing rain,we studied the freezing weather occurred during 18—21 January 2008 by using WRF.The results show that the polluted aerosol suppress regional precipitation,especially the process of severe freezing rain.The microphysical process shows that the formation of freezing rain in Guiyang is caused by supercooled cloud mechanism（warm cloud mechanism）.The polluted aerosol increases the rainwater mixing ratio and ice particles concentration and reduces the content of supercooled rain,resulting in solid precipitation on the ground and suppressing freezing rain.%为了揭示污染大气（气溶胶浓度增加）对于冰冻灾害天气尤其冻雨的影响,利用可分辨云模式（WRF）对2008年1月18—21日中国南方地区一次冰冻灾害天气进行了研究。结果表明：污染气溶胶对此次冰冻天气的区域降水有一定的抑制作用,其中对冻雨的抑制作用更为明显,尤其表现在对较强冻雨过程的抑制作用。微物理过程分析表明,贵阳地区冻雨形成机制表现为过冷云机制（暖云机制）,污染气溶胶使云内云水含量浓度增加,使得冰相粒子撞冻过冷水这一过程进行的更加充分,引起过冷却雨水含量减小,进而导致地面以固态降水为主,抑制了冻雨的产生。