太行山东麓焚风天气的统计特征和机理分析Ⅱ:背风波对焚风产生和传播影响的个例分析  

Feature and Mechanism of the Foehn Weather on East Slope Taihang Mountains Ⅱ:Case Analysis of the Effects of Lee Wave on Foehn Occurring and Moving

作　　者：王宗敏[1,2] 丁一汇[3] 张迎新 范军红 张守保 田利庆 

机构地区：[1]南京信息工程大学大气科学系,江苏南京210044 [2]河北省气象台,河北石家庄050021 [3]中国气象局国家气候中心,北京100081 [4]河北省气象局,河北石家庄050021

出　　处：《高原气象》2012年第2期555-561,共7页Plateau Meteorology

基　　金：中国气象局气象新技术推广项目预报员专项"太行山东麓焚风天气的统计特征及其机理研究"(CMGTG2009YB05)资助

摘　　要：利用中尺度模式WRF3.3对太行山东麓焚风典型个例进行了数值模拟。结果表明,太行山东麓焚风的发生和移动与山脉背风波密切相关。由此建立了太行山东麓焚风的概念模型:西北或偏西气流途经山西盆地、山西境内的山脉或高原,再越过太行山,在其东麓形成背风波。背风波的下沉气流气温按干绝热方式上升,同时下沉气流也会对低层大气产生压缩增温效应,使得太行山东麓产生焚风。背风波即为重力波,可以伴随着下沉气流向下游移动,正变温区同时也向东移动。变温区移动的速度和重力波的传播速度相同。背风波的产生,需要Scorer数向上足够的减小,而且不连续,即要求大气是稳定的且存在明显的风速切变。One typial case of foehn on the east slope of Taihang Mountains is simulated using ARW-WRF V3.3.The result shows that the formation and movement of the foehn is closely related to the lee wave.Based on the relation,a conceptual model of foehn formation on the east slope of Taihang Mountains is proposed.Lee waves develop on the east slope of Taihang Mountains while the northwestly or westly flow goes over the mountains,basins and plateau in the west of Taihang Mountains.The adiabatic heating is due to the decent component of lee waves and the compression warming effect on the lower atmosphere is caused by the downdraft,which lead to the foehn on the east slope of Taihang Mountains.Being one kind of gravity wave,lee waves can propagate downstream,which results in the foehn warming areas moving eastward with the downdraft propagating downstream at the same speed.Theoretical analysis shows that Scorer number decreases upward discontinuously,meaning that the atmosphere is stable and the obvious wind shear exists in the lower atmosphere,which is helpful to the formation of lee wave.

关 键 词：太行山东麓 焚风 概念模型 重力波 

分 类 号：P425.52[天文地球—大气科学及气象学]