Numerical Simulation of Cyclone Sidr Using a Cloud-Resolving Model: Characteristics and Formation Process of an Outer Rainband

Author:

Akter Nasreen1,Tsuboki Kazuhisa2

Affiliation:

1. Hydrospheric Atmospheric Research Center, Nagoya University, Nagoya, Japan, and Department of Physics, Bangladesh University of Engineering and Technology, Dhaka, Bangladesh

2. Hydrospheric Atmospheric Research Center, Nagoya University, Nagoya, and Frontier Research Center for Global Change, Yokohama, Japan

Abstract

Abstract Cyclone Sidr, one of the most devastating tropical cyclones that resulted in several thousand deaths and substantial damages, developed in the north Indian Ocean and made landfall over the Bangladesh coast on 15 November 2007. Observation and simulation results show that Sidr was embedded in a nonuniform environment and contained an intense outer rainband to the east of its center and a significant frontal band to the northwest. A detailed study of the outer rainband is performed by numerical simulation. The eastern band was a long, quasi-straight shape in the meridional direction that remained stationary relative to the cyclone center. This band was composed of convective cells that developed southeast of the center within a synoptic-scale convergence zone and propagated along the band toward the northeast quadrant. The speed of the downwind-propagating cells was greater than that of the cyclone, which resulted in a convective cluster northeast of the center. Only the downwind portion of the band consisted of convection with stratiform rain, whereas the upwind and middle portions contained active convective cells without stratiform rain. The band was located between the synoptic-scale flows of a weakly sheared, gradient-balanced westerly and a strongly sheared, nongradient-balanced prevailing southerly caused by the complex terrain of the Bay of Bengal’s southeast region. Low-level convergence along the band was dominated by cross-band flow from both sides of the band and was confined below 3 km. As the cyclone moved northward, the convergence zone resulted in the extension of band length up to ~800 km. The southerly at the eastern side of the center gradually accelerated and was directed toward the center by a strong pressure gradient force. The flow accumulated a substantial amount of water vapor from the sea in addition to the increased moisture in the lower troposphere, resulting in further intensification of the convective cells.

Publisher

American Meteorological Society

Subject

Atmospheric Science

Cited by 45 articles. 订阅此论文施引文献 订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3