Observation of a Tornado in the Circulation Background of Northeast Cold Vortex
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摘要: 2012年6月12日在吉林省白城市洮北区发生一次龙卷过程 (简称“612”龙卷),对此次龙卷过程天气形势和雷达资料分析结果表明:龙卷发生在高空冷涡的东南象限、中高空急流北侧、低空急流左侧的对流不稳定区域及地面较暖湿的环境中,大气对流参数计算结果显示龙卷过程低层 (0~1 km) 的垂直风切变较强 (为6.0×10-3s-1),抬升凝结高度较低 (低于1 km),且龙卷发生前对流有效位能较大。同时,龙卷过程超过50 dBZ的强核高度均在4 km以下,为低质心的对流系统,龙卷产生于一条带状回波与一近似团状回波合并加强后的强回波带中,并逐渐演变成“S”型,伴有“V”型缺口,中心最强值达61 dBZ。根据多普勒天气雷达导出产品并结合径向速度图反映出“612”龙卷是发生在以龙卷涡旋特征为主的尺度较小且垂直涡度较大 (约为3.65×10-2~3.83×10-2s-1) 的强对流风暴中,持续时间较短。Abstract:
The synoptic situation and Doppler radar data of the tornado process of Taobei District of Baicheng city in Jilin Province on 12 June 2012 (referred as "612" tornado) are analyzed, results are as follows.The tornado process occurrs in the southeast quadrant of the upper cold vortex, and in the convective unstable region of the north of the upper-level jet and the left of the low-level jet, also, in a relatively warm and humid environment of the surface systems. The caculation of atmospheric convective parameters shows that strong vertical wind shear (no less than 6.0×10-3 s-1) occurs at low layer (0-1 km) and relatively low lifting condensation level (no more than 1 km) exists in the tornado process, and the convective available potential energy is large before the tornado occurs. As for the radar echo characteristics, the height of the strong core (no less than 50 dBZ) is below 4 km in the tornado event, making it a low centroid convective system. The tornado occurs in the strong echo zones where a banded echo with an approximate nodular echo join together, and it gradually evolves into an "S" type with "V" type gap, and the echo of the strongest center value reaches 61 dBZ. Using the Doppler radar derived products and the radial velocity map, tornado vortex signature (TVS) could be detected, indicating that "612" tornado occurs in strong convective storm with smaller-scale TVS and larger vertical vorticity (about 3.65×10-2 s-1-3.83×10-2 s-1), having short duration. TVS could be identified in advance before the tornado, so it is very useful for estimation and prediction of tornados.
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[1] 俞小鼎, 郑媛媛, 张爱民, 等.安徽一次强烈龙卷的多普勒天气雷达分析.高原气象, 2006, 25(5):914-924. http://www.cnki.com.cn/Article/CJFDTOTAL-GYQX200605019.htm [2] 郑媛媛, 朱红芳, 方翔, 等.强龙卷超级单体风暴特征分析与预警研究.高原气象, 2009, 28(3):617-625. http://www.cnki.com.cn/Article/CJFDTOTAL-GYQX200903017.htm [3] 姚叶青, 俞小鼎, 郝莹, 等.两次强龙卷过程的环境背景场和多普勒雷达资料的对比分析.热带气象学报, 2007, 23(5):483-490. http://www.cnki.com.cn/Article/CJFDTOTAL-RDQX200705008.htm [4] 何彩芬, 姚秀萍, 胡春蕾, 等.一次台风前部龙卷的多普勒天气雷达分析.应用气象学报, 2006, 17(3):370-375. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=20060363&flag=1 [5] 蒋义芳, 吴海英, 沈树勤, 等.0808号台风凤凰前部龙卷的环境场和雷达回波分析.气象, 2009, 35(4):68-75. doi: 10.7519/j.issn.1000-0526.2009.04.009 [6] 张晰莹, 吴英, 王承伟, 等.东北地区MCC雷达回波特征分析.气象, 2010, 36(8):32-39. doi: 10.7519/j.issn.1000-0526.2010.08.005 [7] 金巍, 曲岩, 安来友, 等.超级单体引发的龙卷天气过程分析.气象, 2009, 35(3):36-43. doi: 10.7519/j.issn.1000-0526.2009.03.005 [8] 纪文君, 刘正奇, 郭湘平, 等.龙卷风生成机制的探讨.海洋预报, 2003, 20(1):14-19. doi: 10.11737/j.issn.1003-0239.2003.01.003 [9] 吴海英, 沈树勤, 蒋义芳, 等.龙卷诱发原因的实例分析.气象科学, 2009, 29(3):335-341. http://www.cnki.com.cn/Article/CJFDTOTAL-QXKX200903010.htm [10] 漆梁波, 陈永林.一次长江三角洲飑线的综合分析.应用气象学报, 2002, 15(2):162-163. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=20040221&flag=1 [11] 廖玉芳, 俞小鼎, 郭庆.一次强对流系列风暴个例的多普勒天气雷达资料分析.应用气象学报, 2003, 14(6):656-662. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=20030683&flag=1 [12] 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 [13] 张一平, 俞小鼎, 吴蓁, 等.区域暴雨过程中两次龙卷风事件分析.气象学报, 2012, 70(5):961-973. doi: 10.11676/qxxb2012.081 [14] 李耀东, 刘健文, 高守亭.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 [15] 姚建群, 戴建华, 姚祖庆, 等.一次强飑线的成因及维持和加强机制分析.应用气象学报, 2005, 16(6):746-753. doi: 10.11898/1001-7313.20050615 [16] 刘宁微, 马雁军, 刘晓梅, 等.辽宁省05-6龙卷风过程的诊断与数值模拟.自然灾害学报, 2007, 16(5):84-90. http://www.cnki.com.cn/Article/CJFDTOTAL-ZRZH200705016.htm [17] 俞小鼎, 姚秀萍, 熊廷南, 等.多普勒天气雷达原理与业务应用.北京:气象出版社, 2006:130-145. http://www.cnki.com.cn/Article/CJFDTOTAL-SYQY201603027.htm [18] 张培昌, 杜秉玉, 戴铁丕.雷达气象学.北京:气象出版社, 2001:396-397. http://www.cnki.com.cn/Article/CJFDTOTAL-SYQY201603027.htm [19] Brown R A, Lemon L R, Burgess D W.Tornado detection by pulsed Doppler radar.Mon Wea Rev, 1978, 106:29-38. doi: 10.1175/1520-0493(1978)106<0029:TDBPDR>2.0.CO;2 [20] Doswell C A.Severe convective storms:An overview.Meteor Monogr, 2001, 50:1-26. [21] Thompson R L, Edwards R, Hart J A.An Assessment of Supercell and Tornado Forecast Parameters with RUC-2 Model Close Proximity Sounding//Preprints 21st Conf on Severe Local Storm.San Antonio:Amer Meteor Soc, 2002:595-598. [22] 章国材.强对流天气分析与预报.北京:气象出版社, 2011:245-246. http://www.cnki.com.cn/Article/CJFDTOTAL-SYQY201603027.htm