基于浙江省自动气象站、杭州和宁波2部多普勒雷达、湖州风廓线雷达及宁波凉帽山370 m高塔等资料, 对2012年4月2日夜间浙江省北部一次灾害性大风过程进行了分析。结果发现, 强冷空气快速下沉触发形成有组织的多单体风暴族导致了湖州地区灾害性大风。多普勒雷达上风暴族表现为弓形回波, 伴有后侧入流缺口, 其中有3个强烈发展的对流单体。导致湖州灾害性大风的下沉运动开始于1 km以下的边界层, 大风从300 m高度及地仅需要2 min。弓形回波尾部发展的强对流单体出流边界与江苏南部东移南下的阵风锋合并导致了嘉兴地区的灾害性大风, 而宁波和舟山地区的灾害性大风是由另一新生成的阵风锋导致。宁波凉帽山高塔资料表明, 当阵风锋靠近时, 塔层318 m上升速度增大, 最大可达1.7 m·s-1; 中低层上升速度变化不大, 阵风锋影响时首先在塔层中上部转为下沉气流, 318 m最大垂直下沉速度可达1.81 m·s-1, 下沉气流造成的水平风速变化率主要出现在232 m以下, 最大1 min超过10 m·s-1, 塔层最强降温比最大全风速变化率滞后1 min左右, 最大降温幅度达1.6℃·min-1, 风温剧变持续了4 min左右。
Based on the data from the automatic weather stations in Zhejiang Province, two Doppler radars in Hangzhou and Ningbo, Huzhou wind profiler and 370 m tower in Liangmaoshan island in Ningbo, a damage wind case across northern Zhejiang Province during the night time of 2 April 2012 was analyzed. The results show that: Well-organized multi-cell windstorms triggered by the quick-sinking strong cold air mass is blamed for the damage wind in Huzhou, windstorms display as a bow echo in Dopplar radar with 3 well-developed convective cells and MARC structure in base velocity images. Huzhou wind profiler data indicates that the sinking flow causing damage wind begins at the boundary layer below 1 km, it takes only 2 min for the damage wind down from 300 m to the ground. Outflow boundary resulted by a convective cell merges with a southeast-going gust front and causes the damage wind in Jiaxing city. Moreover another gust front results the damage winds in Ningbo and Zhoushan cities. Data of the 370 m tower shows that the lift velocity is enhanced with the maximum up to 1.7 m·s-1 at 318 m but few fluctuations at other levels with the gust front approaching. When the gust front passes by, sinking velocity is firstly observed at the upside of the tower with the maximum one-minute sinking velocity up to 1.81 m·s-1 and the maximum fluctuation ratio of velocity more than 10 m·s-1 within one minute which is centered below 232 m of the tower. Temperature dropping is 1 minute lagged behind speed acceleration, with the maximum 1.6℃·min-1 in the middle level. Dramatic wind and temperature change lasts about 4 min.
[1]俞小鼎, 王迎春, 陈明轩, 等.新一代天气雷达与强对流天气预警[J]. 高原气象, 2005, 24(3): 456-464.
[2]张培昌, 杜秉玉, 戴铁丕. 雷达气象学[M]. 北京:气象出版社, 2001: 280-341.
[3]吴芳芳, 王慧, 韦莹莹, 等. 一次强雷暴阵风锋和下击暴流的多普勒雷达特征[J]. 气象, 2009, 35(1): 55-64.
[4]俞小鼎, 姚秀平, 熊廷南, 等. 多普勒天气雷达原理与业务应用[M]. 北京: 气象出版社, 2006: 105-106, 122-124, 185, 197.
[5]Fujita T T. Manual of downburst identification for project NIMROD[R]. Satellite and Mesometeorology Research Paper 156, dept. of Geophysical Sciences, University of Chicargo, 1978: 104-112.
[6]Fujita T T. Tornadoes and downbursts in the context of generalized planetary scales[J]. J Atmos Sci, 1981, 38: 1511-1524.
[7]Atkins N T, Laurent M S. Bow echo mesovortices. Part II: Their genesis[J]. Mon Wea Rev, 2009, 137: 1514-1532.
[8]王俊, 龚佃利, 刁秀广, 等. 一次弓状回波、强对流风暴及合并过程研究Ⅰ: 以单多普勒雷达资料为主的综合分析[J]. 高原气象, 2011, 30(4): 1067-1077.
[9]王俊, 盛日锋, 陈西利. 一次弓状回波、强对流风暴及合并过程研究Ⅱ: 双多普勒雷达反演三维风场分析[J]. 高原气象, 2011, 30(4): 1078-1086.
[10]Johns R H, Hirt W D. Derechos: widespread convectively induced windstorms[J]. Wea Forecasting, 1987, 2: 32-49.
[11]Johns R H, Howard K W, Maddox R A. Conditions associated with long-lived derechos--An examination of the large scale environments[C]. Preprint, 16<sup>th</sup> Conf. on Severe Local Storms, Kananaskis, AB, Canada, Amer Meteoro Soc, 1990: 408-412.
[12]刘娟, 宋子忠, 项阳, 等. 淮北地区一次强风暴的弓形回波分析[J]. 气象, 2007, 33(5): 62-68.
[13]姚叶青, 俞小鼎, 张义军, 等. 一次典型飑线过程多普勒天气雷达资料分析[J]. 高原气象, 2008, 27(2): 373-381.
[14]廖晓农, 俞小鼎, 王迎春. 北京地区一次罕见的雷暴大风过程特征分析[J]. 高原气象, 2008, 27(6): 1350-1362.
[15]潘留杰, 张宏芳, 王楠, 等. 陕西一次强对流天气过程的中尺度及雷达观测分析[J]. 高原气象, 2013, 32(1): 278-289, doi: 10.7522/j.issn.1000-0534.2013.00027.
[16]梁建宇, 孙建华. 2009年6月一次飑线过程灾害性大风的形成机制[J]. 大气科学, 2012, 36(2): 316-336.
[17]王晓芳, 胡伯威, 李灿. 湖北一次飑线过程的观测分析和数值模拟[J]. 高原气象, 2010, 29(2): 471-485.
[18]吴海英, 陈海山, 蒋义芳, 等. “090603”强飑线过程动力结构特征的观测与模拟分析[J]. 高原气象, 2013, 32(4): 1084-1094, doi: 10.7522/j.issn.1000-0534.2012.00102.
[19]裴宇杰, 王福侠, 张迎新, 等. 2009年晚秋河北特大暴雪多普勒雷达特征分析[J]. 高原气象, 2012, 31(4): 1110-1118.
[20]戴建华, 陶岚, 丁杨, 等. 一次罕见飑前强降雹超级单体风暴特征分析[J]. 气象学报, 2012, 70(4): 609-627.
[21]Donald W M. Windex –A new index for forecasting microburst potential[J]. Wea forecasting, 1994, 9: 532-541.
[22]王秀明, 俞小鼎, 周小刚, 等. “6.3”区域致灾雷暴大风形成及维持原因分析[J]. 高原气象, 2012, 31(2): 504-514.
[23]Bradley F S, Robert A. Houze Jr. Rear inflow in squall lines with trailing stratiform precipitation[J]. Mon Wea Rev, 1987, 115: 2869-2889.
[24]周之栩. 基于风廓线雷达资料的暴雪天气过程分析[J]. 浙江气象, 2012, 33(3): 18-20.
[25]阮征, 葛润生. 风廓线仪探测降水云体结构方法的研究[J]. 应用气象学报, 2002, 13(3): 330-338.
[26]刘小红, 洪钟祥. 北京地区一次特大强风过程边界层结构的研究[J]. 大气科学, 1996, 20(2): 223-228.
[27]宗蓉. 多普勒天气雷达的阵风锋识别方法探索[D]. 南京: 南京信息工程大学, 2009: 14.
[28]夏文梅, 慕熙昱, 徐琪, 等. 一次阵风锋过程的数值模拟与分析[J]. 高原气象, 2011, 30(4): 1087-1095.
[29]黄旋旋, 何彩芬, 徐迪峰, 等. 5.6阵风锋过程形成机制探讨[J]. 气象, 2008, 34(7): 20-27.
