Observational Study on Medium-Scale and Tropical Cyclones in the Subtropical frontal zone

副热带锋区中型热带气旋观测研究

• 批准号: 07640573
• 负责人: YAMANAKA Manabu
• 金额: $ 1.47万
• 依托单位: KYOTO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07640573/
• 关键词: Medium-scale cyclone; Tropical cyclone; Subtropical front zone; Cloud clusters; Typhonn eye; Angular momentum; Helicity; Troposphere-stratosphere excange; 対流圈成層圏大気交換

The objective of this project is to study structure and dynamics of the medium-scale extratropical cyclones (appeared in the subtropical front zone near Japan during Baiu and Shurin seasons) and the tropical cyclones, based on observations by the MU,boundary-layr and meteorological radars. The major results of this project are as follows :1.Baiu-and Shrin-frontal medium-scale extratropical cyclonesThe standard observations by the MU radar since 1986 have been reviewed. In particular, the MU radar data obtained by a three-week Baiu observation campaign carried out during 17 June-8 August 1991, as well as those obtained by meteorological radars (X-, C-and Ku bands), radiosondes, meteorological satellites (GMS) and objective analyzes by the Japan Meteorological Agency (JMA), have been studies in detail. An asymmetric structure of the medium-scale cyclone and a hierarchical structure of cloud clusters have been found out. Variations of the tropopausal jet stream, lower-stratospheric inerti … More o-gravity waves and turbulence (eddy diffusivity, etc.) have been also studied.2.Typhoons and their modification processes Two strong typhoons (T9019 on 19-20 September 1990, and T9426 on 29-30 September 1994) passed in the vicinity of the MU radar observatory have been studied in detail. Combining the MU radar data and the JMA storm-track calculations, the tangential and radial wind fields have been analyzed as a function of altitude and radial distance from the typhoon center. Typical axi-symmetric structure appeared before the center passage, whereas asymmetry and transformation into extratropical cyclone were strongly suggested after the center passage. In particular, for T9426 of which the center passed almost over the MU radar observatory, distributions of angular momentum, vorticity and helicity have been analyzed. Conbining these results and the data of surface weather, meteorological radars, rawinsondes, GMS and a boundary-layr radar (at Sakai Electric Power Plant), detailed information on the structure of the typhoon center (eye) have been obtained. The typical warm-core structure has been confirmed, and a spiral structure (similar to a tornade) has been found out. The latter was seen as a local anti-cyclonic rotation in the tangential-wind analyzes.In addition to the scientific results mentioned above, the utility and data analysis method of the VHF/UHF radars for the mesoscale meteorology have been established through this project. Less

本项目的目标是根据MU、边界层和气象雷达的观测，研究中等尺度热带气旋外气旋（在Baiu和Shurin季节出现在日本附近的副热带锋区）和热带气旋的结构和动力学。1.白乌和什林锋面中尺度温带气旋本文回顾了1986年以来中尺度雷达的标准观测资料。特别是，对1991年6月17日至8月8日进行的为期三周的Baiu观测活动所获得的MU雷达数据以及气象雷达（X、C和Ku波段）、无线电探空仪、气象卫星和日本气象厅的客观分析所获得的数据进行了详细研究。发现了中尺度气旋的非对称结构和云团的等级结构。对流层急流、平流层低层惯性、 ...更多信息 o-重力波和湍流（涡流扩散率等）2.台风及其变形过程本文详细研究了1990年9月19-20日和1994年9月29-30日两次经过上海海事大学雷达站附近的强台风T9019和T9426。结合MU雷达资料和JMA风暴路径计算，分析了切向风场和径向风场随高度和距台风中心径向距离的变化。在中心通道之前，出现了典型的轴对称结构，而在中心通道之后，强烈地显示出不对称性和向对流层外气旋的转变。特别是对中心几乎越过MU雷达观测站的T9426，分析了角动量、涡度和螺旋度的分布。结合这些结果和地面天气、气象雷达、探空仪、GMS和边界层雷达（在Sakai发电厂）的数据，获得了台风中心（眼）结构的详细信息。典型的暖心结构已得到确认，并发现了螺旋结构（类似龙卷风）。在切向风分析中，后者被看作是一种局地反气旋旋转。除了上述科学成果外，本项目还建立了VHF/UHF雷达在中尺度气象学中的应用和资料分析方法。少

项目成果

M. D. Yamanaka: "Inertio-gravity-wave-like subtropical multiple tropopauses: Vertical wavenumber spectra of wind and temperature observed by the MU radar, radiosondes and operational rawinsonde network." J. Atmos. Terr. Phys.58. 785-805 (1996)

M. D. Yamanaka：“惯性重力波类副热带多重对流层顶：MU 雷达、无线电探空仪和运行的拉文探空仪网络观测到的风和温度的垂直波数谱。”

T. Shimomai: "Application of wavelet analysis to wind disturbances observed with MST radar techniques." J. Atmos. Terr. Phys.58. 683-696 (1996)

T. Shimomai：“小波分析在 MST 雷达技术观测到的风扰动中的应用。”

I.Takayabu et al.: "An observational study of a cyclogenesis in the lee side of Japan Central Montains" Meteor.Atmos.Phys.61. 39-53 (1996)

I.Takayabu 等人：“日本中央山脉背风面气旋发生的观测研究”Meteor.Atmos.Phys.61。

Y.Shibagaki: "Hierarchical structures of vertical velocity variations and precipitating clouds near the Baiu frontal cyclone center observed by the MU and meteorological radars." J.Meteor.Soc.Japan. 75(in press). (1997)

Y.Shibagaki：“MU和气象雷达观测到的Baiu锋面气旋中心附近的垂直速度变化和降水云的层次结构。”

I.Takayabu: "An observatoinal study of a cyclogenesis in the lee side of Japan Central Montains" Meteor.Atmos.Phys.61. 39-53 (1996)

I.Takayabu：“日本中央山脉背风面气旋发生的观测研究”Meteor.Atmos.Phys.61。