Nina(7503)台风于1975年8月在河南林庄造成24 h 1062 mm的特大暴雨,成为中国大陆台风暴雨之最.1975年,发生在中国大陆的这场特大暴雨,冲垮水库河堤,洪水泛滥,酿成大灾.中国24 h 1000 mm或以上的台风特大暴雨,称之为极端暴雨(Extreme rain),除这次外,还出现过多次,但都发生在台湾.分析表明,台风特大暴雨并不完全依赖于台风强度或内核对流强度,还和环境不同尺度环流系统与台风的相互作用、下垫面对台风环流的作用及台风上层云微物理过程有关.因此,登陆台风残涡复苏所下暴雨往往会超过强台风的暴雨;台风外围尤其是台风倒槽辐合区所下的暴雨也可能会超过台风中心暴雨.造成极端暴雨的台风有一些显著特点:极端暴雨产生在登陆或近海台风维持和停滞时段;低空急流、季风涌、双台风作用及内陆大面积水体是登陆台风获得水汽和潜热能量的主要来源;中纬度槽与登陆台风或残涡相互作用,可向台风或残涡提供位能和不稳定能量,使其产生更大降水;山脉地形对极端暴雨的形成起重要作用;台风高层云团中的微物理过程,对极端暴雨的形成有重要作用.
Review of Typhoon Very Heavy Rainfall in China
Numerous tropical cyclones (TCs) bring very heavy rainfall in China when precipitation is equal to or more than 1000 mm/24h.Typhoon Nina (7503) produced precipitation of 1062 mm/24h in Henan province 2-3 days after it made landfall in mainland China.That the other TCs produced extreme precipitations were in Taiwan China.The precipitation rates in 24 hours were super typhoon Herb (9608) with 1748.5 mm,super typhoon Carla (6718) with 1672.6 mm,super typhoon Morakot (0908) with 1632.5 mm,super typhoon Gloria (6312) with 1248 mm,super typhoon Lynn (8719) with 1136 mm,super typhoon Parma (0917) with 1086.5 mm in turn.The precipitation rate of 1748.5 mm/24h produced by Herb is the top record.Those typhoons caused extreme rainfalls in Taiwan did not land in Taiwan except Herb and Morakot.Generally,rainfall inland caused by TCs including landfall typhoons and coastal typhoons depend on following three aspects.1)TC inner core and outer structure such as the strong convective burst in cloud wall,mesoscale vortices and shear lines inside the TC circulation as well as the cloud microphysical process in the upper level of TC.2) Environmental influences include moisture supply,vertical wind shear (VWS),jet stream and upper level outflow.An very important environmental effect is TC interacts with a mid-latitude trough or monsoon surge and the peripheral weather systems.3)Underlying surface forcing includes the offshore water properties,coastal terrain,mountain range topography and huge inland water surface etc.Coastal terrain could lead to asymmetric structure of rain rate and distribution.Mountain range to pography could strengthen the upward motion or induce occurrence of a mesoscale vortex.Both of them would increase rainfall.Huge inland water surface would be also favorable to increase TC rainfall.The observational study and numerical simulation showed that the following conditions would help a TC or its remnant to produce very heavy rainfall (even extreme rainfall).Especially when landfall TC has sufficient energy to compensate the ground frictional consuming and maintain its vortex over land surface.Furthermore,extreme rainfall usually appear in a time period of TC when its motion slowdown or stagnant.Sustainment and stagnancy of landfall TC are the very important condition for the very heavy rainfall.The other necessary condition is the moisture supply.Plentiful moisture could be transported into TC through moisture channel of a low level jet,or cloud clusters of monsoon surges engulfed by TC vortex.It suggested that another way for TC to acquire moisture was from the interaction of binary tropical cyclones or huge inland water surface.Apart from the water supply,the other important process is that the TC or its remnant interacts with a mid-latitude westerly trough.Some of the extreme precipitations of TCs were caused by strong convective burst in eye wall or strong convergence between dry trade wind and TC humid southerly flow in the area of inverted trough.Most extreme rainfall processes have showed that the mountain range topographic effect would provide noticeable contribution to the rainfall.Cloud micro-physical process including the seeding effects in the top level of a TC could be a key factor in producing very heavy rainfall or extreme rainfall.There left us a big room in this area for the further study.
NETL
NSTL
万方数据
维普
