THE DIAGNOSTIC ANALYSIS OF THE VORTICITY AND CIRCULATION BUDGET DURING THE DEVELOPMENT AND EVOLUTION OF SUPER TYPHOON SANBA
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摘要: 台风的增强过程与气旋性涡度的急剧发展相伴。使用滑动平均的空间滤波方法对WRF模式的模拟结果进行尺度分离, 进而诊断分析台风SANBA突然增强过程中垂直涡度及环流的发展演变特征。结果表明, 台风突然增强的过程中, 眼壁区上升速度增大, 暖心结构增强, 同时垂直涡度迅速增强。当SANBA从热带风暴发展为强热带风暴时, 对流层低层辐散辐合及垂直速度分布的不均匀对台风涡旋结构的增强强度相当, 在台风内部以增强区域为主同时与减弱区域交错分布; 当SANBA发展增强为强台风时, 对流层低层的散度项与倾斜项在台风中心附近均表现为强的正中心, 台风低层径向入流的增强导致低层辐合加强对台风的增强起到主要作用。台风中心区域平均环流强度随台风的不断增强而不断增大, 且从900 hPa高度不断向高层发展, 其中环流方程中的EED/EET项的发展变化可以表征台风发展初期散度项和倾斜项的主要变化。Abstract: Typhoon enhancement processes accompany with the rapid development of cyclonic vorticity. Based on WRF model simulation results, we diagnose and analyze the vertical vorticity and circulation during the development and evolution of super typhoon SANBA.In order to distinguish convective structures from system structures, a spatial filter is derived using a two-dimensional weight moving average, the weight of which is defined by a window function. The result shows that the updraft increases, warm core structure gradually becomes obvious, and vertical vorticity rapidly enhances with the development of the typhoon. When tropical storm develop into a strong tropical storm (the 30th hour of the simulation), the intensity of the tilting term and divergence term are similar in the lower troposphere, which shows that the enhancement of typhoon vortex structure is closely related with the divergence/convergence and the non-uniform distribution of vertical velocity. When SANBA developed to a super typhoon (the 50th hour of the simulation), both the tilting term and divergence term have strong positive centers near the typhoon center in the lower troposphere, and the contribution of the divergence term is greater than that of the tilting term. The low-level radial inflow enhancement leads to enhanced low-level convergence, playing a major role in the development of typhoon. Developing upwards from 900 hPa to the high level, the circulation intensity is enhanced with the typhoon intensification. Specifically, the change and development of the EED/EET item in the circulation equations may characterize the major changes in the divergence term and tilting term in the early development of typhoon.
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Key words:
- synoptics /
- typhoon /
- diagnostic /
- vorticity /
- circulation
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图 3 同图 2, 但为位温(单位: K)的分布
图 4 同图 2, 但为垂直速度(单位: m/s)的分布
图 9 同图 7, 但为2012年9月13日02时(t=50)的分布
图 10 同图 8, 但为2012年9月13日02时(t=50)的分布
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[1] 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. [2] 林志强, 王鹏祥, 唐叔乙.西北太平洋热带气旋残留低压对中国大陆地区降水的影响[J].气象学报, 2016, 74(1): 46-59. [3] 赵珊珊, 任福民, 高歌, 等.近十年我国热带气旋灾害的特征研究[J].热带气象学报, 2015, 31(3):424-434. [4] KRISHNAMURTI T N, PATTNAIK S, STEFANOVA L, et al. The hurricane intensity issue[J]. Mon Wea Rev, 2005, 133(7): 1 886-1 912. [5] 端义宏, 余晖, 伍荣生.热带气旋强度变化研究进展[J].气象学报, 2005, 63(5): 636-645. [6] 陈联寿, 孟智勇.我国热带气旋研究十年进展[J].大气科学, 2001, 25(3): 420-432. [7] 朱雪松, 余晖, 尹球, 等.台风"梅花"(1109)双眼墙生消过程的卫星资料分析[J].热带气象学报, 2014, 30(1): 34-44. [8] ZENG Z, WANG Y, WU C C. Environmental dynamical control of tropical cyclone intensity-An observational study[J]. Mon Wea Rev, 2007, 135(1): 38-59. [9] 叶成志, 李昀英.热带气旋"碧利斯"与南海季风相互作用的强水汽特征数值研究[J].气象学报, 2011, 69(3): 496-507. [10] 沈阳, 张大林, 沈新勇.风垂直切变对飓风波尼(1998)结构与强度的影响[J].气象学报, 2012, 70(5): 949-960. [11] 赵威, 赵海坤, 韦志刚, 等. MJO与西北太平洋热带气旋活动的关系及其年代际变化[J].热带气象学报, 2015, 31(2): 237-246 [12] ELSNER J B, KOSSIN J P, JAGGER T H. The increasing intensity of the strongest tropical cyclones[J]. Nature, 2008, 455(7 209): 92-95. [13] 熊秋芬, 张昕, 陶祖钰.一次温带气旋涡度场演变特征及气旋发生发展机制分析[J].气象, 2016, 42(3): 294-304. [14] 蔡其发, 黄思训, 高守亭, 等.计算涡度的新方法[J].物理学报, 2008, 57(6): 3912-3919. [15] 李英, 陈联寿, 王继志.热带气旋登陆维持和迅速消亡的诊断研究[J].大气科学, 2005, 29(3): 482-490. [16] 费建芳, 刘磊, 黄小刚, 等.热带气旋眼墙非对称结构的研究综述[J].气象学报, 2013, 71(5): 987-995. [17] 丁治英, 邢蕊, 徐海明, 等.多台风的相互作用和水平涡度与垂直涡度的关系[J].热带气象学报, 2014, 30(5): 825-835. [18] 李永平, 詹宗明.用涡度场捕捉台风"鲇鱼"的动态[J].气象研究与应用, 2012, 33(2): 9-10. [19] 杨成彬, 郑祖光, 王雨.用非线性模型研究环境温度场和涡度场对台风发生、发展的影响[J].大气科学, 1994 (S1): 810-819. [20] CREIGHTON G A, HART R E, CUNNINGHAM P. A spatial filter approach to evaluating the role of convection on the evolution of a mesoscalevortex[J]. J Atmos Sci, 2013, 70(7): 1 954-1 976. [21] DIMEGO G J, BOSART L F. The transformation of Tropical Storm Agnes into an extratropical cyclone. Part Ⅱ: Moisture, vorticity and kinetic energy budgets[J]. Mon Wea Rev, 1982, 110(5): 412-433. [22] 孙建华, 赵思雄.登陆台风引发的暴雨过程之诊断研究[J].大气科学, 2000, 24(2): 223-237. [23] 吕美仲, 侯志明, 周毅.动力气象[M].北京:气象出版社, 2004:110. [24] 温晓培, 隆霄, 张述文, 等.边界层参数化方案对台风SANBA初生阶段影响的数值模拟研究[J].热带气象学报, 2016, 32(3): 346-357. [25] HOLLAND G J. An analytic model of the wind and pressure profiles in hurricanes[J]. Mon Wea Rev, 1980, 108(8): 1 212-1 218. [26] 汪钟兴.积云对流对涡度场和散度场的反馈作用[J].大气科学, 1988, 12(2): 168-173.