【作者】 王亦平；

【导师】 陆维松； 王元；

【作者基本信息】 南京信息工程大学 ， 应用气象学， 2007， 博士

【摘要】 在2000年12号台风（Prapiroon）影响期间，其外围对淮河流域东北部造成了一次罕见的特大暴雨。本文利用非静力平衡的中尺度模式ARPS（V5.2），使用1°×1°NCEP再分析资料，运用ADAS三维同化系统对雷达回波、红外云图进行了同化，然后进行了48小时数值模拟，并设计了四个敏感性试验。通过对几种不稳定、CVV、水平垂直环流与中尺度深湿对流系统之间关系的诊断分析，揭示了本次台风外围异常暴雨形成的内在机理。研究结果表明：（1）对流云团的演变分为三个阶段：分别是30日01～12时、30日13～23时、31日00～06时。四条对流带在响水交汇，一是高空槽前的对流系统向东南方向移动；二是沿西南低空急流方向的西南．东北对流带；三是响水偏南方向生成的对流带；四是响水东南方向沿海地区生成向西北移动的对流带。（2）中低层对流不稳定是深湿对流系统发生的先决条件，深湿对流系统的中低层还是斜压不稳定、条件对称不稳定，而对应中高层必须有斜压不稳定和条件对称不稳定。由于低层存在辐合，使得周围湿空气向暴雨区集中，对流单体在响水汇聚，且发生合并增强，从台风左前方向响水输送对流不稳定能量，是暴雨区对流不稳定重新建立和加强的重要机制。（3）深湿对流系统的高层西（北）侧为负MPV₂柱，东（南）侧为正MPV₂柱。深对流系统中惯性不稳定柱总是伴随强的惯性稳定柱，且惯性不稳定与惯性稳定相间分布。深湿对流系统西（南）侧为负CVV柱，而东（北）侧为正CVV柱，负CVV柱对深湿对流单体起激发作用。（4）四个敏感性试验分别揭示了潜热加热、台风、高空槽、副高使对流不稳定区范围扩大，并使对流不稳定的高度升高，加强了台风向暴雨中心输送的高能舌，向暴雨中心输送更多的不稳定能量；增加大气中高层斜压性，使对称不稳定加大；加强低层辐合和低层水汽通量散度辐合、并增强对流单体上升运动；增加水平θ_e梯度和风垂直切变，产生深的负CVV柱。（5）潜热加热能够引起热成风调整，并驱动中尺度环流，产生中尺度辐合线和β中尺度涡旋。台风、高空槽、副高等天气系统对中尺度辐合线和β中尺度涡旋的激发也有显著的影响，对对流单体起组织和加强的作用；促使暴雨中心附近垂直方向顺切变环流的生成，补充对流单体加强和发展所需的干冷气流，增强高低空急流及非地转性，使高低空急流的耦合加强，从而加大风垂直切变，增加高层惯性不稳定，加大低层惯性稳定，导致高层辐散和低层辐合均加强，并产生正涡度柱，形成散度与涡度相互耦合的动力机制。更多还原

【Abstract】 During the appearance of Prapiroon typhoon (No. 12) in 2000, a torrential rainoccurred in its periphery. Using a nonhydrostatic mesoscale Model (ARPS(V5.2)),with ADAS 3-D data assimilation system, reanaiysis data of NCEP, radar echo andGMS5 satellite image had been applied to simulate the event. Four sensitivityexperiments had been designed. The relationship between deep moist mesoscaleconvective system (DMMCS) and instability, CVV, horizontal and vertical circulationare analyzed, and the mechanism of this torrential rain is revealed. The conclusionsare following:(1) There are three phases during the evolution of the convective clouds:3001-3012BST, 3013-3023BST, and 3100-3106BST. There are four convective beltswhich converge on Xiangshui. The first belt lies in front of upper trough, and movessoutheastward; the second one lies in the southwest, and moves from southwest tonortheast; the third one lies in the south; and the last one lies in the southeast.(2) The middle-low level convective instability is the precondition of theoccurrence of DMMCS, not only baroclinic instability and conditional symmetryinstability lie in the middle-low level, but also lie in the middle-upper level. Becauseof the low-level convergence, the surrounding moisture centralize in the heavy rainarea, the convergence and merging enhancement of convection cells, and theconvective instability energy transporting from the left-front of typhoon, are theimportant mechanism of the rebuilding of convective instability.(3) At the west (east, south, north) of DMMCS, there lies negative (positive,positive, negative) MPV2 column. In DMMCS, there is an alternative distributionbetween inertial instability column and inertial stability column. At the west and south(east and north), there lie negative (positive) CVV columns, and negative CVVcolumn is beneficial to deep moist convection.(4) Four sensitivity experiments show that latent heat, typhoon, upper trough,subtropical high have important effects separately. The convective instability zonecan be expanded, and the convective instability height can be rose. The high energytongue which is from the typhoon transporting to the heavy rain cell is enhanced. More instability energy is transported to the cell. The middle-upper level baroclinityand symmetry instability are enhanced. Being the convergence of low-levelconvergence and the moisture flux divergence are enhanced, the ascending motion isenhanced. Because of the horizontal gradient ofθ_e and wind vertical shear are added,the CW column is deepened.(5) The thermal wind can cause adjustment by latent heat, then drive themeso-scale circulation, so meso-scale convergence line and meso-β-scale vortexformed. Typhoon, upper trough, and subtropical high have important effect on thedevelopment of meso-scaie convergence line and meso-β-scale vortex, so theconvective cells can be organized and intensified. They have important effect on thedevelopment of downshear circulation, which can supply the dry and cold air, nearbythe heavy rain cell. Then, the convective cells can be intensified. They have importanteffect on upper- and low-level jet, and ageostrophy. The coupling of upper- andlow-level jet can be enhanced, and the wind vertical shear can be added. As theupper-level inertial instability and the low-level inertial stability, the upper-leveldivergence and the low-level convergence can be intensified, the positive vorticityappear. Then, the coupling of divergence and vorticity is intensified.更多还原