基于湿位涡与螺旋度的一次西南低涡强降水分析
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摘要
利用NCEP再分析资料、地面观测资料、FY-2E卫星TBB资料和融合降水资料,应用湿位涡和螺旋度原理,对2015年8月17-19日一次西南低涡强降水过程进行诊断分析,得出以下结论:水汽通量散度辐合区的分布对降雨落区有较好的指示性,中尺度对流云团特征与低涡和降水发展趋势有着密切联系。降雨落区及其中心位置与该时刻700 hPa湿位涡有较好的对应关系,降雨中心靠近MPV1负值与正值的交界处,而MPV1负值区内的降水较弱。对流层中低层MPV1负值与MPV2正值的重合区是强降水发生的警戒区,并且对流层中低层层结的不稳定、气流的辐合上升运动以及西南温湿气流的输送是此次强降水产生的重要机制。对流层中低层z-螺旋度正值区的分布对相应时段降水的落区具有较好的指示性,相对螺旋度正值区的大值中心位置与未来6 h降水中心的落区呈现出高度一致,且降水中心靠近相对螺旋度正值中心一侧的等值线密集区。
Using NCEP re-analysis data, the observation data, FY-2 E TBB data and merged precipitation data, applying the theories of moist potential vorticity and helicity, a diagnostic analysis of a Southwest Vortex rainstorm process from 17 to 18 August 2015 was carried out. The results are as the following: the distribution of the convergence region of moisture flux divergence can be taken as a good indicator for rainfall area and the characteristics of mesoscale convective cloud clusters are closely related to the development of Southwest Vortex and precipitation. The spatial distribution of the 700 hPa moist potential vorticity has a good correspondence with rainfall area and its center location in the corresponding period. The strong rainfall center is near the junction of the negative value area and the positive value area of MPV1, while the rainfall in the negative value area of MPV1 is weak. The overlapping area of the negative value of MPV1 and the positive value of MPV2 in the mid-low troposphere is a warning area for the storm. Stratification instability, upward movement of intensive convergence and the transfer of southwest warm and humid air in the midlow tropo-sphere are important mechanisms for the generation of the rainstorm. The distribution of the positive value area of z-helicity can give good indication to rainfall area in the corresponding period. The center position of the positive value area of relative helicity is highly consistent with the next 6 h precipitation center, and the precipitation center is close to the densest isolines by the side of the positive value center of relative helicity.
Using NCEP re-analysis data, the observation data, FY-2 E TBB data and merged precipitation data, applying the theories of moist potential vorticity and helicity, a diagnostic analysis of a Southwest Vortex rainstorm process from 17 to 18 August 2015 was carried out. The results are as the following: the distribution of the convergence region of moisture flux divergence can be taken as a good indicator for rainfall area and the characteristics of mesoscale convective cloud clusters are closely related to the development of Southwest Vortex and precipitation. The spatial distribution of the 700 hPa moist potential vorticity has a good correspondence with rainfall area and its center location in the corresponding period. The strong rainfall center is near the junction of the negative value area and the positive value area of MPV1, while the rainfall in the negative value area of MPV1 is weak. The overlapping area of the negative value of MPV1 and the positive value of MPV2 in the mid-low troposphere is a warning area for the storm. Stratification instability, upward movement of intensive convergence and the transfer of southwest warm and humid air in the midlow tropo-sphere are important mechanisms for the generation of the rainstorm. The distribution of the positive value area of z-helicity can give good indication to rainfall area in the corresponding period. The center position of the positive value area of relative helicity is highly consistent with the next 6 h precipitation center, and the precipitation center is close to the densest isolines by the side of the positive value center of relative helicity.
引文
[1] 卢敬华.西南低涡概论[M].北京:气象出版社,1986.
[2] 陈启智,黄奕武,王其伟,等.1990-2004年西南低涡活动的统计研究[J].南京大学学报(自然科学版),2007,43(6):633-642.
[3] 何光碧.西南低涡研究综述[J].气象,2012,38(2):155-163.
[4] 郁淑华,高文良.高原低涡与西南涡结伴而行的不同活动形式个例的环境场和位涡分析[J].大气科学,2017,41(4):831-856.
[5] 李国平,刘行军.西南低涡强降水的湿位涡诊断分析[J].应用气象学报,1994,5(3):354-360.
[6] 陈忠明,徐茂良,闵文彬,等.1998年夏季西南低涡活动与长江上游强降水[J].高原气象,2003,22(2):162-167.
[7] 李跃清,徐祥德.西南涡研究和观测试验回顾及进展[J].气象科技进展,2016,6(3):134-140.
[8] 段海霞,陆维松,毕宝贵.凝结潜热与地表热通量对一次西南低涡强降水影响分析[J].高原气象,2008,27(6):1315-1323.
[9] 顾清源,周春花,青泉,等.一次西南低涡特大强降水过程的中尺度特征分析[J].气象,2008,34(4):39-47.
[10] 江玉华,杜钦,赵大军,等.引发四川盆地东部强降水的西南低涡结构特征研究[J].高原气象,2012,31(6):1562-1573.
[11] 刘晓波,储海.一次西南低涡东移引发长江中下游强降水的诊断研究[J].气象,2015,41(7):825-832.
[12] 赵大军,江玉华,李莹.一次西南低涡强降水过程的诊断分析与数值模拟[J].高原气象,2011,30(5):1158-1169.
[13] 卢萍,李跃清,郑伟鹏,等.影响华南持续性强降水的西南涡分析和数值模拟[J].高原气象,2014,33(6): 1457-1467.
[14] 刘晓冉,李国平.一次东移型西南低涡的数值模拟及位涡诊断[J].高原气象,2014,33(5):1204-1216.
[15] 黄楚惠,顾清源,李国平,等.一次高原低涡东移引发四川盆地强降水的机制分析[J].高原气象,2010,29(4):832-839.
[16] 张虹,李国平,王曙东.西南涡区域强降水的中尺度滤波分析[J].高原气象,2014,33(2):361-371.
[17] 宋雯雯,李国平.两类涡度矢量对四川盆地一次强降水过程的分析应用[J].高原气象,2016,35(6):1464-1475.
[18] 吴国雄,蔡雅萍,唐晓菁.湿位涡和倾斜涡度发展[J].气象学报,1995,53(4):387-405.
[19] Woodall G R.Qualitative Forecasting of Tornadic Activity Using Storm-relative Environmental Helicity Preprint[C].16th conference on severe local storm helicity,1990:311-315.
[20] Davies-Jones R P,D W Burgess,M Foster.Test of Helicity as Tornado Forecasting Parameter.Preprint,16th Conference on severs local storms[C].Kananaskis Park,AB,Cananda,Amer Meteor Soc,1990:588-593.
[21] 寿绍文,王祖锋.1991年7月上旬贵州地区强降水过程物理机制的诊断研究[J].气象科学,1998,18(3):231-238.
[22] 黄楚惠,李国平.基于螺旋度和非地转湿Q矢量的一次东移高原低涡强降水过程分析[J].高原气象,2009,28(2):319-326.
[23] 赖绍钧,何芬,赵汝汀,等.“龙王”(LONGWANG)台风过程湿位涡的诊断分析[J].气象科学,2007,27(3):266-271.
[24] 李静楠,潘晓滨,臧增亮,等.一次华北强降水过程的湿位涡诊断分析[J].强降水灾害,2016,35(2):158-165.
[2] 陈启智,黄奕武,王其伟,等.1990-2004年西南低涡活动的统计研究[J].南京大学学报(自然科学版),2007,43(6):633-642.
[3] 何光碧.西南低涡研究综述[J].气象,2012,38(2):155-163.
[4] 郁淑华,高文良.高原低涡与西南涡结伴而行的不同活动形式个例的环境场和位涡分析[J].大气科学,2017,41(4):831-856.
[5] 李国平,刘行军.西南低涡强降水的湿位涡诊断分析[J].应用气象学报,1994,5(3):354-360.
[6] 陈忠明,徐茂良,闵文彬,等.1998年夏季西南低涡活动与长江上游强降水[J].高原气象,2003,22(2):162-167.
[7] 李跃清,徐祥德.西南涡研究和观测试验回顾及进展[J].气象科技进展,2016,6(3):134-140.
[8] 段海霞,陆维松,毕宝贵.凝结潜热与地表热通量对一次西南低涡强降水影响分析[J].高原气象,2008,27(6):1315-1323.
[9] 顾清源,周春花,青泉,等.一次西南低涡特大强降水过程的中尺度特征分析[J].气象,2008,34(4):39-47.
[10] 江玉华,杜钦,赵大军,等.引发四川盆地东部强降水的西南低涡结构特征研究[J].高原气象,2012,31(6):1562-1573.
[11] 刘晓波,储海.一次西南低涡东移引发长江中下游强降水的诊断研究[J].气象,2015,41(7):825-832.
[12] 赵大军,江玉华,李莹.一次西南低涡强降水过程的诊断分析与数值模拟[J].高原气象,2011,30(5):1158-1169.
[13] 卢萍,李跃清,郑伟鹏,等.影响华南持续性强降水的西南涡分析和数值模拟[J].高原气象,2014,33(6): 1457-1467.
[14] 刘晓冉,李国平.一次东移型西南低涡的数值模拟及位涡诊断[J].高原气象,2014,33(5):1204-1216.
[15] 黄楚惠,顾清源,李国平,等.一次高原低涡东移引发四川盆地强降水的机制分析[J].高原气象,2010,29(4):832-839.
[16] 张虹,李国平,王曙东.西南涡区域强降水的中尺度滤波分析[J].高原气象,2014,33(2):361-371.
[17] 宋雯雯,李国平.两类涡度矢量对四川盆地一次强降水过程的分析应用[J].高原气象,2016,35(6):1464-1475.
[18] 吴国雄,蔡雅萍,唐晓菁.湿位涡和倾斜涡度发展[J].气象学报,1995,53(4):387-405.
[19] Woodall G R.Qualitative Forecasting of Tornadic Activity Using Storm-relative Environmental Helicity Preprint[C].16th conference on severe local storm helicity,1990:311-315.
[20] Davies-Jones R P,D W Burgess,M Foster.Test of Helicity as Tornado Forecasting Parameter.Preprint,16th Conference on severs local storms[C].Kananaskis Park,AB,Cananda,Amer Meteor Soc,1990:588-593.
[21] 寿绍文,王祖锋.1991年7月上旬贵州地区强降水过程物理机制的诊断研究[J].气象科学,1998,18(3):231-238.
[22] 黄楚惠,李国平.基于螺旋度和非地转湿Q矢量的一次东移高原低涡强降水过程分析[J].高原气象,2009,28(2):319-326.
[23] 赖绍钧,何芬,赵汝汀,等.“龙王”(LONGWANG)台风过程湿位涡的诊断分析[J].气象科学,2007,27(3):266-271.
[24] 李静楠,潘晓滨,臧增亮,等.一次华北强降水过程的湿位涡诊断分析[J].强降水灾害,2016,35(2):158-165.