Dynamic Control of Tropical Cyclone Genesis

 

Prof. Bin Wang 

University of Hawaii, USA

 

邀请人 ： 包 庆 研究员

 

2024年6月7日（周五）14:00

3号楼二层第三会议室

 

报告摘要:

Future changes in the genesis frequency and distribution of tropical cyclones (TCs) are important for society, yet uncertain. Confidence in the model projections largely relies on whether we can physically explain why the models projected such changes. The TC genesis potential index (GPI) has been extensively used to understand the large-scale processes governing climate variability and future changes in TC genesis (TCG). Whether the GPIs, derived using climatological mean data, can be applied to interpret TCG climate variations and future change is our keen concern. The relative roles of the thermodynamic versus dynamic factors in TCG also remain elusive.

We established a Dynamic GPI (DGPI), consisting of the four circulation parameters (the 500hPa vertical motion, 850hPa absolute vorticity, vertical wind shear, and 500hPa shear vorticity of zonal winds), provides a diagnostic tool for understanding climate variation and future changes in TCG. It better represents interannual-decadal variations of TCG frequency in the western Pacific and Southern Hemisphere oceans. The results from a TC-permitting global model ascertain the four leading dynamical factors as the most influential in the present-day simulation and future projection of TCG. 

Analysis of the CMIP6 multi-model climate simulations indicates that patterns and frequency of projected TCG are largely governed by dynamic effects—human-induced changes in atmospheric circulation, including mid-level upward motion, lower-to-mid-level cyclonic vorticity, and vertical wind shear. Conversely, the thermodynamic effect—a result of increased Maximum Potential Intensity in a warmer climate—would yield TCG patterns opposite to the model projections. Therefore, dynamic changes in response to anthropogenic greenhouse gas emissions are essential in determining the response of tropical cyclones to global warming.

 

报告人简介:

Bin Wang（王斌）, 美国夏威夷大学大气科学系教授，国际太平洋研究中心季风研究首席科学家，美国气象学会会士，美国地球物理学会会士，曾于2015年获得美国气象学会最高奖“罗斯贝研究奖”。Bin Wang教授的研究领域为气候动力学、动力气象学、热带气象学和地球物理流体力学。在季风气候、气候变化、热带季节内震荡、海气相互作用以及气候可预报性等方面发表了许多开创性成果。曾任夏威夷大学气象系主任、世界气候研究计划/气候变率与可预报性/亚澳季风研究委员会主席、亚太经合组织气候中心科学顾问委员会主席、中国科学院大气物理研究所大气科学和地球流体力学数值模拟国家重点实验室学术委员会海外主任 。