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2003年4月江西一次强对流天气过程的诊断分析
A Severe Convection Weather of Jiangxi in April 2003
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摘要: 利用NCEP/NCAR再分析资料、TBB资料、探空资料及多普勒雷达资料等对2003年4月12日发生在江西以及福建北部的强对流天气过程进行了诊断分析。结果表明:此次强对流天气过程是在高空槽和低层低涡切变线的有利形势下产生的, 这种下层暖湿、上层干冷的对流不稳定层结非常有利于强对流天气的产生; 强对流天气发生发展伴有多个中尺度对流云团东移南压的演变过程; 多普勒雷达资料分析表明, 冰雹发生时可观测到79 dBz的反射率因子极值并伴有弓状回波; 对流有效位能积累、释放随时间的演变过程, 对于此次强对流天气过程有很好的指示意义; 强对流天气发生前高层的干冷空气倾斜状向下侵入到对流层中低层附近, 对此次强对流天气的发生发展起了非常重要的作用; 能量锋区及锋区上强的垂直涡柱为该次强对流天气过程提供了有利的热力和动力学条件。Abstract: Convection weather is one of the most severely disastrous weather phenomena in China, with features of small spacial scale, short life span, sudden emergence and great damaging force.It is always very difficult to make an accurate analysis and forecast for severe convection weather in the daily operational work.With the application of Doppler radar and the development of numerical weather prediction technology, the know ledge about the severe convection weather and the related mechanisms is also improved in recent years.Effective ways have been developed in some countries to be applied in the analysis and forecast for severe weather.Examples can be found in U S A, where parameter estimation, graphics identification and statistical characteristics based on climate have been put into operational use for forecast of hailstones and tornadoes, and proved to be useful in improving the accuracy.Much improvement is also made in China Meteorological Administration in recent years in severe weather observation, many new instruments, such as radars, automatic weather stations, lightening detection and GPS/MET vapor detection instruments etc have been gradually put into operational use.These new data definitely provide forecasters and researchers good opportunities to study the severe convection weather and improve the forecast accuracy.Using NCEP/NCAR daily meteorological reanalysis data, sounding data, TBB and Doppler radar images, a typical convection induced severe weather process occurred on April 12—13, 2003 in Jiangxi and northern Fujian is diagnosed and analyzed, the result shows that this severe convection weather takes place under favorable conditions of upper trough coupling with a low-level vortex and shear environments. Lower level southwesterly jet contributes as a vapor transportation passage.Dry and cold airs of upper level overlapping upon wet and warm airs in low er level create a convectively unstable layer.Under this condition, convective weather could be easily initiated and high instability energy releases with suitable triggering mechanism. Several mesoscale convective clouds involve in the development of the severe weather, and deep convection mostly concentrates on the frontal parts of the clouds where TBB isolines converging with high gradient.Also the Doppler radar images show that the maximum reflection up to 79 dBz is reported during hail-fall, and bow echo could be observed.Convective available potential energy (CAPE) is a meaningful sign in the process of convection event.Before the severe weather, CAPE grow s gradually and accumulates.The severe weather initiates soon after the CAPE reaches its peak values, then with CAPE's releasing and becoming weak rapidly, severe weather downgrades.Dry air intrusion to mid-level from upper level plays an important role in the development of convection.Energy-front zone and strong vertical vorticity-pole provides thermodynamic and dynamic conditions for this severe convection weather.
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Key words:
- severe convection weather;
- CAPE;
- dry intrusion
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图 1 2003年4月12日江西和福建北部出现强对流天气的站点
Fig. 1 Severe convection weather stations in Jiangxi and northern Fujian on April 12, 2003
图 2 2003年4月12日08:00高低层环流形势图
(细实线为500 hPa位势高度, 单位: gpm; 矢量为850 hPa水平风场; 粗实线为850 hPa切变线或槽线)
Fig. 2 Upper and lower level circulations at 08:00 on April 12, 2003
(thin solid lines denote 500 hPa geopotential height, unit : gpm; vectors denote 850 hPa horizontal wind fields; thick solid lines denote 850 hPa shear-line or trough)
图 3 2003年4月12日12:00—17:00 TBB分布图
(单位: ℃; 图中化给出TBB值低于-40 ℃的等值线图; 其中A, B, C, D分别为对流云团编号)
Fig. 3 TBB evolution during 12:00—17:00 on April 12, 2003
(unit:℃; only for TBB value lower than-40 ℃; A, B, C, D denote the numbering of cloud clusters)
图 4 对流有效位能水平分布及其随时间演变 (单位: J/kg)
(a)2003年4月12日08:00水平分布图, (b)2003年4月10—14日江西弋阳ECAP时间演变图
Fig. 4 Convective available potential energy distribution and its time series (unit : J/kg)
(a)ECAP distribution at 08:00 on April 12, 2003, (b)ECAP time series during April 10—14 at Yiyang, Jiangxi
图 5 2003年4月11—13日南昌站点垂直速度高度-时间剖面图 (单位: Pa/s)
Fig. 5 Height-time cross section of vertical wind at Nanchang during April 11—13, 2003 (unit : Pa/s)
图 6 2003年4月12日14:00过南昌站点相对湿度 (实线, 单位: %)、气流场 (矢量箭头, 由南北风速与垂直速度合成) 沿115.9°E垂直剖面图
Fig. 6 Cross section of relative humidity (solid line, unit: %), airflow (vector, combination of v and ω) along 115.9°E at 14:00 on April 12, 2003
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[1] Johns R H, Doswell Ш C A.Severe local storms forecasting.Wea Forecasting, 1992, 7: 588-612. doi: 10.1175/1520-0434(1992)007<0588:SLSF>2.0.CO;2 [2] Mills G A, Colquhoun J R. Objective prediction of severe thunderstorm environment:Preliminary results linking a decision tree with an operational regional NWP model. Wea Forecasting, 1998, 13: 1078-1092. doi: 10.1175/1520-0434(1998)013<1078:OPOSTE>2.0.CO;2 [3] Kalnay E, Kanamitsu M, Kistler R, et al.The NCEP/NCAR 40-year reanalysis project.Bull Amer Meteor Soc, 1996, 77 (3): 437-471. doi: 10.1175/1520-0477(1996)077<0437:TNYRP>2.0.CO;2 [4] 许爱华, 张英, 刘献耀.江西"暖区"强对流天气的热力和动力条件诊断分析.气象, 2001, 27(5):30-34. http://www.cnki.com.cn/Article/CJFDTOTAL-QXXX200105008.htm [5] 卢乃锰, 吴蓉璋.强对流降水云团的云图特征分析.应用气象学报, 1997, 8(3): 269-275. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=19970339&flag=1 [6] 朱君鉴, 刁秀广, 黄秀韶.一次冰雹风暴的CINRAD/SA产品分析.应用气象学报, 2004, 15(5):579-589. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=20040571&flag=1 [7] 李耀东, 高守亭, 刘健文.对流能量计算及强对流天气落区预报技术研究.应用气象学报, 2004, 15(1):10-20. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=20040102&flag=1 [8] 刘玉玲.对流参数在强对流天气潜势预测中的作用.气象科技, 2003, 31(3):147-151. http://www.cnki.com.cn/Article/CJFDTOTAL-QXKJ200303003.htm [9] 杨国祥, 何齐强.北京雷暴大风和冰雹临近预报的研究.空军气象学院学报, 1994, 15(3): 202-211. [10] Huntrieser H, Schiesser H H, Schmid W, et al.A New Thunderstorm Index for Switzerland. 18th Conference on Severe Local Storms. Amer Meteor Soc, 1996: 255-259. [11] 刘健文, 郭虎, 李耀东, 等.天气分析预报物理量计算基础.北京:气象出版社, 2005: 117-122. [12] 赵秀英, 田宜泉, 吴宝俊, 等. 风暴强度指数 (SSI). 国外强对流天气的应用研究. 北京: 气象出版社, 2001: 335-339. [13] Renno' N O, Ingersoll A P.Natural convection as a heat engine:A theory for CAPE.J Atmos Sci, 1996, 53:572-585. doi: 10.1175/1520-0469(1996)053<0572:NCAAHE>2.0.CO;2 [14] 姚秀萍, 于玉斌, 杨耀芳. 干侵入在温带气旋发展中的作用. 国外强对流天气的应用研究. 北京: 气象出版社, 2001: 141-145. [15] 于玉斌, 那济海, 姚秀萍. 干侵入在快速发展气旋中的作用. 国外强对流天气的应用研究. 北京: 气象出版社, 2001: 146-150. [16] 于玉斌, 姚秀萍.干侵入的研究及其应用进展.气象学报, 2003, 61 (6): 769-778. http://www.cnki.com.cn/Article/CJFDTOTAL-QXXB200306013.htm [17] 姚秀萍, 于玉斌, 刘还珠. 2003年7月淮河流域一次暴雨过程中干冷空气的侵入∥新世纪气象科技创新与大气科学发展 (7). 北京: 气象出版社, 2003: 78-82. [18] 周海光, 刘延英, 刘蔚. 1998年广东省三次暴雨过程的湿有效能量分析.应用气象学报, 2006, 17(1) :10-18. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=20060102&flag=1 [19] 袁佳双, 寿绍文. 1998年华南大暴雨冷空气活动的位涡场分析.南京气象学院学报, 2001, 24(1): 92-98. http://www.cnki.com.cn/Article/CJFDTOTAL-NJQX200101011.htm [20] 刘健文, 郭虎, 李耀东, 等.天气分析预报物理量计算基础.北京:气象出版社, 2005:7-8. -
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