摘要
基于常规天气观测资料和美国FNL1°×1°逐6 h再分析资料,对2014年4月23—24日昌吉地区一次寒潮天气过程进行分析和总结,并利用WRF3.7(The Weather Research and Forecasting Model)中尺度数值模式对10 m风场和地形作用进行分析,结果表明:(1)这次寒潮天气过程出现在欧洲高压脊东南衰退、西西伯利亚低槽东南下进入新疆爆发的大尺度环流背景下。(2)这次强寒潮过程的高位涡强冷空气来自欧亚北部和北极地区的平流层下部和对流层上部。(3)低层强西北风急流向山脉辐合,造成暖湿气流在天山迎风坡强烈爬升,是暴雪发生的触发机制。通过地形敏感性试验表明天山地形的抬升作用减弱所引起的降水变小。
Based on the conventional weather observation data and the FNL 1°×1° 6 h reanalysis data, cold wave process in Changji area was analyzed and summarized from A p r i l 23rd to A p r i l 24th ,2014,nd then the wind fi le d features and the topographic function on the cold wave were further studied through conducting a set o f numerical experiments using WRF3.7.The results indicate that, f i rst ly , the cold wave event occurred in the context o f the southeastern depression of the European ridge of high pressure and the large-scale circulation of the eruption of X inj iang in the southeast of the western Siberian low trough. Secondly,the high vort ic ity cold air was from the lower stratosphere and the upper troposphere in northern Eurasia and A rc tic regions. T h ird ly , the weather affected by the southwest water vapor channel, from the Indian Ocean after a long journey through the east of Sichuan basin,along the northwest in the transportation around the Tibetan plateau, the terrain block caused by the loss was relatively smal l, down near region in Gansu provincereached 410 Nandnor thernbranchofvaporwast ranspor tedtothewestaf termeet ingin Chang^^i area. Final ly , the strong northwesterly winds converge to the mountains, resulting in a strong climax of the warm and humid airflow in the windward slope o f the Tianshan Mountains,which was the triggering mechanism of blizzard.Terrain sensitivity test results show that the precipitation was weakened by the u p l if t effect o f the Tianshan Mountains.
出处
《沙漠与绿洲气象》
2018年第1期86-94,共9页
Desert and Oasis Meteorology
基金
国家自然科学基金项目(41275105)
关键词
寒潮
等熵面位涡
数值模拟
cold wave
isentropic potential vort ic ity
numerical simulation
