THE DIAGNOSTIC ANALYSIS ON THE RAPID INTENSIFICATION OF TYPHOON MEKKHALA (2006) OVER OFFSHORE CHINA
-
摘要: 利用ERA-5再分析资料、日本葵花8号卫星黑体亮温资料以及中国气象局上海台风研究所台风最佳路径集资料,对2020年第6号台风“米克拉”(2006)近海强度急剧增强进行诊断分析。(1)比常年偏暖的29~ 30 ℃的南海东部海温是“米克拉”急剧增强的有利下垫面条件;200 hPa加强东移的南亚高压、500 hPa加强西伸的副高、低层加强的偏南-西南急流是主要影响系统;相对比深层和高层大气,持续低于4 m/s的低层大气垂直风切是重要因子。(2)“米克拉”的增强主要体现在对流层低层动能的不断增强,在台风急剧增强过程中,中低层的气旋性涡度、低层辐合强度、中高层辐散强度以及上升运动均明显加强;对流层中高层动能在台风急剧增强前的减小可能与增强的高空出流相关。(3)在“米克拉”急剧增强前,深对流云系强度不断增强,但覆盖面积变化不大;在急剧增强阶段,深对流云系组织的更加紧实集中,覆盖面积明显增大。Abstract: Based on the ERA-5 reanalysis data (0.25 °×0.25 °), the hourly black body temperature (TBB) data of the Japanese Himawari-8 satellite, and the best track data provided by Shanghai Typhoon Institute, a diagnostic analysis was made on the rapid intensification(RI) of typhoon Mekkhala (Coded No. 2006) over the offshore region of China. The results are shown as follows. (1) Abnormally high sea surface temperature (SST) of 29 to 30 ℃ in the eastern South China Sea provided favorable underlying surface conditions for the RI of Mekkhala, which occurred under the influencle of the following systems: the South Asia high was strengthening and moving eastward at 200 hPa while the subtropical high was strengthening and moving westward at 500 hPa, and a low-level south-southwest jet was significantly strengthening. Compared with the deep and upper atmosphere, the environmental vertical wind shear (VWS) in the lower atmosphere, which was continuously below 4m/s, was one of the factors causing the RI of Mekkhala. (2) The RI of Mekkhala was mainly reflected in the enhancement of kinetic energy in the lower troposphere. During its RI, cyclonic vorticity in the middle and lower layers, middle-upper-level divergence, low-level convergence and the ascending motion all strengthened significantly. The decrease of kinetic energy in the upper and middle troposphere before the RI might be related to the enhanced upper air outflow. (3) Before the RI of Mekkhala, the intensity of the deep convective cloud system increased, but the coverage area changed little. During its RI, the organization of the deep convective cloud system was more compact and concentrated, and the coverage area expanded obviously.
-
Key words:
- Mekkhala /
- offshore /
- rapid intensification /
- deep convective cloud system
-
表 1 台风“米克拉”基本情况
时间
(月/日/时)中心位置 中心气压
(hPa)最大风速
(m/s)6 h变压
(hPa)12 h风速变化
(m/s)备注 8/9/08 117.9 °E,15.2 °N 1 004 13 / / / 8/9/14 118.1 °E,16.0 °N 1 004 13 0 2 / 8/9/20 118.4 °E,16.8 °N 1 002 15 -2 2 / 8/10/02 118.5 °E,17.7 °N 1 002 15 0 3 / 8/10/08 118.5 °E,19.0 °N 1 000 18 -2 5 / 8/10/14 118.6 °E,20.3 °N 998 20 -2 7 / 8/10/20 118.5 °E,21.6 °N 990 25 -8 8 急剧增强 8/11/02 118.2 °E,22.9 °N 985 28 -5 13 急剧增强 8/11/08 117.8 °E,24.1 °N 975 38 -10 -13 急剧增强 8/11/14 117.0 °E,25.5 °N 1 002 15 27 / / -
[1] 阎俊岳. 近海热带气旋迅速加强的气候特征[J]. 应用气象学报, 1996, 7(1): 28-35. [2] 寿绍文, 姚秀萍. 爆发性发展台风合成环境场的诊断分析[J]. 大气科学, 1995, 19(4): 487-493. [3] 夏友龙, 郑祖光, 刘式达. 台风内核与外围加热对其强度突变的影响[J]. 气象学报, 1995, 53(4): 423-430. [4] 郑祖光, 夏友龙, 刘式达. 台风内核与外围的强度突变[J]. 气象学报, 1996, 54(3): 294-302. [5] 余晖, 吴国雄. 湿斜压性与热带气旋强度突变[J]. 气象学报, 2001, 59(4): 440-449. [6] 胡皓, 端义宏. 南海热带气旋迅速加强环境场因子的影响分析[J]. 热带气象学报, 2016, 32(3): 299-310. [7] 白莉娜, 王元. 环境风速垂直切变对西北太平洋热带气旋强度变化的影响[J]. 热带气象学报, 2013, 29(6): 955-962. [8] 王伟, 余锦华. 东风和西风切变环境下西北太平洋热带气旋快速增强特征的对比[J]. 大气科学学报, 2013, 36(3): 337-345. [9] HARNOS D S, NESBITT S W. Convective structure in rapidly intensifying tropical cyclones as depicted by passive microwave measurements[J]. Geophys Res Lett, 2011, 38(7): L07805. [10] KAPLAN J, DEMARIA M, KNAFF J A. A revised tropical cyclone rapid intensification index for the Atlantic and eastern North Pacific basins[J]. Wea Forecasting, 2010, 25(1): 220-241. [11] ALVEY Ⅲ G R, ZAWISLAK J, ZIPSER E. Precipitation properties observed during tropical cyclone intensity change[J]. Mon Wea Rev, 2015, 143(11): 150904101551007. [12] 梁建茵, 陈子通, 万齐林, 等. 热带气旋"黄蜂"登陆过程诊断分析[J]. 热带气象学报, 2003, 19(S1): 45-55. [13] 于玉斌, 陈联寿, 杨昌贤. 超强台风"桑美"(2006)近海急剧增强特征及机理分析[J]. 大气科学, 2008, 32(2): 405-416. [14] 于玉斌, 段海霞, 炎利军, 等. 超强台风"桑美"(2006)近海急剧增强过程数值模拟试验[J]. 大气科学, 2008, 32(6): 1 365-1 378. [15] 高拴柱, 吕心艳, 王海平, 等. 热带气旋莫兰蒂(1010)强度的观测研究和增强条件的诊断分析[J]. 气象, 2012, 38(7): 834-840. [16] 薛霖, 李英, 许映龙, 等. 台湾地形对台风Meranti(1010)经过海峡地区时迅速增强的影响研究[J]. 大气科学, 2015, 39(4): 789-801. [17] SUSCA-LOPATA G, ZAWISLAK J, ZIPSER E J, et al. The role of observed environmental conditions and precipitation evolution in the rapid intensification of Hurricane Earl (2010)[J]. Mon Wea Rev, 2015, 143(6): 2 207-2 223. [18] 于玉斌, 姚秀萍. 西北太平洋热带气旋强度变化的统计特征[J]. 热带气象学报, 2006, 22(6): 521-526. [19] 朱乾根. 天气学原理和方法[M]. 北京: 气象出版社, 2007. [20] CHAN J, DUAN Y, SHAY L K. Tropical cyclone intensity change from a simple ocean-atmosphere coupled model[J]. J atmos, 2001, 58 (2): 154-172. [21] 覃丽, 吴启树, 曾小团, 等. 对流非对称台风"天鸽"(1713)近海急剧增强成因分析[J]. 暴雨灾害, 2019, 38(3): 212-220. [22] WANG Y, RAO Y, TAN Z M, et al. A statistical analysis of the effects of vertical wind shear on tropical cyclone intensity change over the Western North Pacific[J]. Mon Wea Rev, 2015, 143(9): 3 434-3 453. [23] 陈联寿, 丁一汇. 西太平洋台风概论[M]. 北京: 科学出版社, 1979. [24] WU Q, HONG J, RUAN Z. Diurnal variations in tropical cyclone intensification[J]. Geophys Res Lett, 2020, 47(23): e2020GL090397. [25] 赵文化, 单海滨. 基于红外窗区与水汽通道对流云团识别方法研究[J]. 气象, 2018, 44(6): 814-824.