摘要
应用中尺度数值模式,在控制试验(CTL)的基础上,研究高空西风急流强度变化对长江中下游一次暴雨过程降水强度和雨带位置的影响。结果表明:控制试验对高低空急流位置、降水强度有很好的模拟能力;模式敏感性试验中高空西风急流增强(SJet)/减弱(WJet)的方法是合理的、可行的;SJet和WJet两者对低层环流和雨带及降水强度的影响过程不同,前者有利于加强低空急流,降水在CTL雨带的南侧会增强,在北侧会减弱,雨带位置南撤;后者则相反,雨带位置向北推进;SJet所引起的暴雨中心位置偏南,WJet所引起的暴雨中心位置偏北。
The influence of the change of the upper level westerly jet on the precipitation intensity and the position of rain band of a torrential rain process in the middlelower reaches of the Yangtze river is investigated in this paper using the MM5 (V2).Numerical experiment results show that the control experiment (CTL) is able to successfully simulate the position of the upper/low level jet and the intensity of precipitation;in the sensitive experiment,the technique used to strengthen/weaken the upper level westerly jet (SJet/WJet) is reasonable as well as feasible.The influencing processes of SJet and WJet on the low level circulation and the precipitation intensity of rain band are different;SJet is favorable to the strengthening of the low level jet,thus leading to the increase of precipitation south of and the reduction north of the rain band in the CTL,this corresponds to the circumstance of the withdrawal of the rain band;while WJet is favorable to the northward advance of the rain band.Therefore,SJet results in the position of torrential rain center south than normal,and WJet leads to the position north than normal.
出处
《南京气象学院学报》
CSCD
北大核心
2003年第5期595-604,共10页
Journal of Nanjing Institute of Meteorology
基金
国家自然科学基金资助项目(40275014)
国家自然科学基金资助项目(40135020)
中科院知识创新工程重要方向项目(ZKCX2-SW-210)
