CAJ | 학술논문

利用中尺度 WRF模式、NCEP/NCAR再分析格点资料及常规气象观测资料，对2009年8月28-30日河南省南部一次强暴雨过程进行中尺度数值模拟，借助模式输出的模拟数据计算位势涡度及位势涡度方程收支，并利用位涡收支方程对此次暴雨过程进行诊断分析。结果表明，WRF模式对此次暴雨过程的模拟效果较好，模拟暴雨强度及落区与实况较一致，位势涡度能够较好地反映此次暴雨过程的动力及热力特征。位涡异常高值区与暴雨中心有较好的对应关系，暴雨中心大致位于位涡高值中心东南侧。位涡收支方程中各收支项同样能够反映此次暴雨过程的动力、热力性质。暴雨发展过程中大气中低层位涡局地增加，位涡局地变化大值中心对应暴雨中心。各收支项中，引起中低层位涡局地变化的贡献主要来源于潜热加热作用、水平平流作用、垂直输送作用及摩擦作用。其中潜热加热与水平平流作用对暴雨区中低层正变位涡起正贡献作用，潜热加热作用有利于位涡局地增加，水平平流作用易于低层位涡向流场辐合区聚集，引起局地位涡增加；垂直输送及摩擦作用对中低层位涡变化表现为负贡献作用，垂直作用易于将中低层位涡向高层输送，使得低层位涡减小，高层位涡增加。在摩擦作用下，低层位涡被大量耗散，使得中低层位涡局地减小。
이용중척도 WRF모식、NCEP/NCAR재분석격점자료급상규기상관측자료，대2009년8월28-30일하남성남부일차강폭우과정진행중척도수치모의，차조모식수출적모의수거계산위세와도급위세와도방정수지，병이용위와수지방정대차차폭우과정진행진단분석。결과표명，WRF모식대차차폭우과정적모의효과교호，모의폭우강도급락구여실황교일치，위세와도능구교호지반영차차폭우과정적동력급열력특정。위와이상고치구여폭우중심유교호적대응관계，폭우중심대치위우위와고치중심동남측。위와수지방정중각수지항동양능구반영차차폭우과정적동력、열력성질。폭우발전과정중대기중저층위와국지증가，위와국지변화대치중심대응폭우중심。각수지항중，인기중저층위와국지변화적공헌주요래원우잠열가열작용、수평평류작용、수직수송작용급마찰작용。기중잠열가열여수평평류작용대폭우구중저층정변위와기정공헌작용，잠열가열작용유리우위와국지증가，수평평류작용역우저층위와향류장복합구취집，인기국지위와증가；수직수송급마찰작용대중저층위와변화표현위부공헌작용，수직작용역우장중저층위와향고층수송，사득저층위와감소，고층위와증가。재마찰작용하，저층위와피대량모산，사득중저층위와국지감소。
Using mesoscale WRF model,conventional meteorological data and NCEP/NCAR reanalysis da-ta,the severe rainstorm process from 28 to 30 August in Henan Province is simulated and diagnosed with the equation of potential vorticity budget.Using the simulation results,this paper diagnoses the rainstorm by the potential vorticity and potential vorticity budget.The results show that WRF model has good simu-lation results to severe rainstorm.The simulated intensity and location of the rainstorm is well consistent with the observation.Potential vorticity can reflect the main dynamic and thermodynamic characteristics of the rainstorm.High potential vorticity value area has a better correlation with the rainstorm center,which is located in the southeast of the high potential vorticity area.The various items of potential vorticity budget can well show the main dynamic and thermodynamic characteristics of the rainstorm.The potential vorticity in the low-middle atmosphere increases locally with the large value area corresponding to the rain-storm center in the process of rainstorm developing.Among the items of the potential vorticity budget,the latent heat and the horizontal advection and vertical transportation and friction are the main contribution i-tems ,of which the horizontal advection and the latent heat contribute positively to the local changes of po-tential vorticity.The latent heat makes the potential vorticity gradually increase.The horizontal advection is helpful for the potential vorticity to gather to the convergence zone of the flow field.The vertical trans-portation and friction make the negative contribution to the local changes of potential vorticity.The verti-cal transportation can transfer the potential vorticity from the lower to the high-level and reduce the low-level potential vorticity.Under the influence of the friction,the potential vorticity in low-level is dissipa-tived and reduced.