非纬向高空急流与远距离台风中尺度暴雨的研究

丁治英; 张兴强; 何金海; 徐海明

非纬向高空急流与远距离台风中尺度暴雨的研究

南京气象学院大气科学系, 江苏南京210044

基金项目: "国家重点基础研究发展规划"我国重大气候和天气灾害形成机理和预测理论研究项目G1998040908;国家自然科学基金49335060(49335061)

计量
- 文章访问数: 1241
- HTML全文浏览量: 0
- PDF下载量: 2097
- 被引次数: 0
出版历程
- 收稿日期: 1999-12-28
- 修回日期: 2000-10-31

THE STUDY OF STORM RAINFALL CAUSED BY INTERACTION BETWEEN THE NON-ZONAL HIGH LEVEL JET STREAK AND THE FAR DISTANT TYPHOON

Nanjing Institute of Meteorology, Nanjing 210044, China

摘要

摘要: 首先对非纬向高空急流与远距离台风暴雨的相关统计进行了分析,得出:暴雨发生时,200hPa高空一般为西南风急流(90.%),暴雨区位于高空急流右后方。暴雨增幅时,200hPa高空急流有一个增强转竖的趋势。用MM4模式对9711号台风8月19日00时～20日00时(GMT)进行了数值模拟和诊断分析。认为:远距离台风暴雨与非纬向高空急流、低层台风倒槽形成有关。高空急流右后方形成的高层辐散场主要与非纬向风有关。高层辐散场使低层产生变风场辐合,从而导致台风倒槽的形成与暴雨加强。在暴雨增幅过程中,用中尺度系统分析发现在高空急流右后方300hPa以下存在一支中尺度环流,该环流对暴雨的维持与加强有密切联系,它的生成与高空急流的非纬向性增强有关。在高空急流右后侧的次级环流与降水产生的潜热反馈、高空非纬向风场(v场)的增强之间存在一种有利于远距离暴雨增幅的正反馈机制。
- 非纬向高空急流 /
- 远距离台风中尺度暴雨 /
- 动力减压
Abstract: In this paper,correlation statistics and analysis between the storm rainfall far from typhoon and non-zonal high level jet streak(NHJ) were carried out. The results show that: The high level jet streak(HJ) in 200hPa is constantly SW(90.2 percent) during the period of which storm rainfall occurs. Rainfall area lies in the right behind regions of HJ axes. While storm is being intensive,the HJ has a trend that non-zonal feature become stronger. In terms of MM4 model,numerical simulation and diagnosis were carried out for 9711 typhoon on 19th to 20th August,1997. The far distant rainfall storm is tightly correlative to the NHJ and low level typhoon trough. The divergence field of HJ is related to v component. The upper level can caused the allobaric wind convergence at low level. This is the result of the form of low level typhoon trough and the strength of the storm. By scale analysis,there exists one branch of middle scale transverse inverse circulation in the right entrance regions behind the HJ below the 300hPa level,which is very important to the keeping and strengthening of rainfall storm. This branch of inverse circulation is relative to the reinforcement of HJ's non-zonal characteristics. From the field of middle scale divergence field and non-zonal wind field we can find that: The stronger symmetry caused by transverse circulation in the two sides of HJ,rainfall's feedback and reinforcement of HJ's non-zonal characteristics leaded to positive feedback mechanism that was favorable of storm rainfall's strengthening.
- non-zonal high level jet streak /
- storm rainfall far distant from typhoon /
- dynamical press decreasing zone

HTML全文

参考文献(12)

[1]	UCCELLINI L W,JHONSON D R.The coupling of upper and lower tropspheric jet stream and implication for the development of severe convective storm[J].Mon Wea Rev,1979,107:682－703.
[2]	黄安丽,高坤.对流层高低空耦合作用的动力学分析[J].杭州大学学报,1982,9:356－364.
[3]	丁治英,陈久康,吕君宁.不同雨强台风的诊断对比与数值试验研究[J].南京气象学院学报,1995,18:234－241.
[4]	罗亚丽,丁一汇,仪清菊.登陆台风形势下的暴雨过程[A].丁一汇.中尺度天气和动力学研究[C].北京:气象出版社,1996.60－92.
[5]	励申申,寿绍文.登陆台风维持和暴雨增幅实例的能量学分析[J].南京气象学院学报,1995,18:383－388.
[6]	蒋尚城.远距离台风影响西风带特大暴雨的过程模式[J].气象学报,1983,41:147－158.
[7]	朱乾根,林锦瑞,寿绍文,等.天气学原理和方法[M].北京:气象出版社,1992.718－719.
[8]	ANTHES R A,HSIE E Y,KUO Y-H.Description of the penn state/NCAR mesoscale model version4 (MM4)[B].NCAR Technical Note,NCAR/TN-82+STR[R].1987.66.
[9]	Kuo Y H.On formation and intensification of tropical cyclones through latent heat release by cumulus convection[J].J Atmos Sci,1965,22:40－63.
[10]	丁治英,陈久康,吕君宁.200 hPa急流区大尺度重力惯性波与暴雨[J].南京气象学院学报,1997,15:101－110.
[11]	夏大庆,郑良杰,董双林,等.气象场的几种中尺度分离算子及其比较[J].大气科学,1983,7:303－311.
[12]	陈久康,丁治英.高低空急流与台风环流耦合下的中尺度暴雨系统[A].丁一汇.中尺度天气和动力学研究[C].北京:气象出版社,1996.171－179.