2010年6月江西一次持续性暴雨过程的定量诊断分析
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摘要
利用常规气象站每6 h一次的降水资料和National Centers for Environmental Prediction(NCEP)Final operational analysis(FNL)资料,运用局地经向环流诊断方程对2010年6月17—20日江西的罕见持续性暴雨的两阶段降雨过程作了定量诊断分析,结果表明:潜热加热是造成两阶段暴雨最为重要的原因,且在第二阶段激发的上升运动明显强于第一阶段;经向温度平流、经向西风动量平流和边界条件对两阶段暴雨过程都有一定的正贡献;平均温度垂直输送和纬向西风动量平流在第一阶段为负贡献,在第二阶段转为正贡献。结合对应天气形势分析发现:500 h Pa青藏高原东南侧浅槽的生成、东移、加深,与减弱东南移的切断低涡合并形成东北西南走向的深厚低压槽(暴雨区位于槽前)是第二阶段潜热加热激发的上升运动较第一阶段强的主要原因;高空西风急流出口区(入口)反气旋切变侧的辐合下沉(辐散抽吸)是平均西风动量纬向平流在第一(二)阶段中为(负)正贡献的主要原因;平均温度由低层向高层(高层向低层)输送是造成平均温度垂直输送在第一(二)阶段中为负(正)贡献的主要原因;中低层暖平流激发的上升运动是平均温度平流在两阶段降雨过程中起正贡献的主要原因。
Using operational observation data and National Centers for Environmental Prediction(NCEP) Final operational(FNL) analysis data, a quantitative diagnosis is carried out for the upward branch of a local meridional circulation over Jiangxi during 0200 17 to 1400 18May(first stage) and 0800 19 to 2000 20 May(second stage). The results show that the upward motion is mainly associated with latent heating in both the two stages. The stimulated omega is large in second stage(-0.353 Pa·s-1) than first stage(-0.212) Pa·s-1. The meridional temperature advection, the meridional westerly momentum advection and the boundary conditions have positive contributions, while the vertical transportation of mean temperature and the zonal westerly momentum advection have negative contributions to upward motion in first stage. In addition to the meridional temperature advection, the meridional westerly momentum advection and the boundary conditions, the mean temperature vertical transportation and the zonal westerly momentum advection have turned positive contributions to upward motion in second stage.The corresponding analyses indicate the following results.(1) The 500 h Pa shallow rough over southeast Tibetan Plateau moving eastward and deepening, merging to a cut-off low which moved southeastward are the main causes of the upward movement stimulated by the latent heating enhanced in the second stage.(2) The convergence sinking(divergence pumping) of the upper westerly jet exit(entrance) anticyclone shear side is the main reason for positive(negative) contribution of mean westerly momentum zonal advection in the first(second) stage.(3) The upward(downward) transportation of the mean temperature is the main reason for negative( positive) contribution in the first(second) stage.(4)The warm advection is main reason for the positive contribution in two rainfall stages.
Using operational observation data and National Centers for Environmental Prediction(NCEP) Final operational(FNL) analysis data, a quantitative diagnosis is carried out for the upward branch of a local meridional circulation over Jiangxi during 0200 17 to 1400 18May(first stage) and 0800 19 to 2000 20 May(second stage). The results show that the upward motion is mainly associated with latent heating in both the two stages. The stimulated omega is large in second stage(-0.353 Pa·s-1) than first stage(-0.212) Pa·s-1. The meridional temperature advection, the meridional westerly momentum advection and the boundary conditions have positive contributions, while the vertical transportation of mean temperature and the zonal westerly momentum advection have negative contributions to upward motion in first stage. In addition to the meridional temperature advection, the meridional westerly momentum advection and the boundary conditions, the mean temperature vertical transportation and the zonal westerly momentum advection have turned positive contributions to upward motion in second stage.The corresponding analyses indicate the following results.(1) The 500 h Pa shallow rough over southeast Tibetan Plateau moving eastward and deepening, merging to a cut-off low which moved southeastward are the main causes of the upward movement stimulated by the latent heating enhanced in the second stage.(2) The convergence sinking(divergence pumping) of the upper westerly jet exit(entrance) anticyclone shear side is the main reason for positive(negative) contribution of mean westerly momentum zonal advection in the first(second) stage.(3) The upward(downward) transportation of the mean temperature is the main reason for negative( positive) contribution in the first(second) stage.(4)The warm advection is main reason for the positive contribution in two rainfall stages.
引文
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[12]邹海波,刘熙明,吴俊杰,等.定量诊断2008年初南方罕见冰冻雨雪天气[J].热带气象学报,2011,27(3):345-356
[13]陈炳洪,林良勋,张维,等.5·23广东特大暴雨过程特点及数值诊断分析[J].热带气象学报,2011,27(5):738-744
[14]黄忠,吴乃庚,冯业荣,等.2007年6月粤东持续性暴雨的成因分析[J].气象,2008,34(4):53-60
[15]温之平,吴乃庚,冯业荣等.定量诊断华南春旱的形成机理[J].大气科学,2007,31(6):1 223-1 236
[16]覃慧玲,简茂球,袁卓建,等.1984年南海夏季风经向环流强迫因子的诊断分析[J],热带气象学报,2004,20(1):39-50
[17]HOLTON J R.An introduction to dynamic meteorology[M].4nd,Elsevier Academic Press,2004:68,166
[2]尹洁,郑婧,张瑛,等.一次梅雨锋特大暴雨过程分析及数值模拟[J].气象,2011,37(7):827-837
[3]杨婷,苗春生,唐振飞.江西“6.19”特大暴雨天气过程诊断分析[J].气象与减灾研究,2010,33(3):34-41
[4]张瑛,肖安,马力,等.WRF耦合4个陆面过程对“6.19”暴雨过程的模拟研究[J].气象,2011,37(9):1 060-1 069
[5]肖安,张瑛,马中元,等.江西“2010.6.19”特大暴雨水汽输送过程分析[J].气象水文海洋仪器,2011,36-42
[6]周祖刚,姜勇强,张高硬,等.2010年6月江西特大暴雨数值模拟及湿位涡分析[J].湖北农业科学,2013,52(18),4 371-4 374
[7]孔期.2010年6月大气环流和天气分析[J].气象,2010,36(9):120-125
[8]袁卓建,王同美.局地经向环流的诊断方程[A]//中国科学院大气物理研究所.东亚季风和中国暴雨[G].北京:气象出版社,1998:496-505
[9]YUAN Z J,WANG T M,HE H Y,et al.A Comparison between numerical simulations of forced Local Hadley Circulation in East Asian and Indian Monsoon Redions[J].Advances in Atmosphric Sciences,2000,17(4):538-554
[10]袁卓建,王同美,郭裕福.东亚季风经向环流数值模拟及结果分析II算法设计[J].中山大学学报(自然科学版),2000,40:97-100
[11]陈桂兴,黎伟标,袁卓建,等.1998年长江流域洪水期大气季节内振荡特征及机理研究[J].中国科学D辑,2004,34(6):562-572
[12]邹海波,刘熙明,吴俊杰,等.定量诊断2008年初南方罕见冰冻雨雪天气[J].热带气象学报,2011,27(3):345-356
[13]陈炳洪,林良勋,张维,等.5·23广东特大暴雨过程特点及数值诊断分析[J].热带气象学报,2011,27(5):738-744
[14]黄忠,吴乃庚,冯业荣,等.2007年6月粤东持续性暴雨的成因分析[J].气象,2008,34(4):53-60
[15]温之平,吴乃庚,冯业荣等.定量诊断华南春旱的形成机理[J].大气科学,2007,31(6):1 223-1 236
[16]覃慧玲,简茂球,袁卓建,等.1984年南海夏季风经向环流强迫因子的诊断分析[J],热带气象学报,2004,20(1):39-50
[17]HOLTON J R.An introduction to dynamic meteorology[M].4nd,Elsevier Academic Press,2004:68,166