Influences of large-scale flow variations on the track evolution of typhoons Morakot (2009) and Megi (2010): Simulations with a global variable-resolution model

Ching Yuang Huang, You Zhang, William C. Skamarock, Li Huan Hsu

研究成果: 雜誌貢獻期刊論文同行評審

8 引文 斯高帕斯(Scopus)

摘要

Influences of large-scale flow variations on the track evolution of two typhoons, moderate Morakot (2009) and superintense Megi (2010), are investigated using the global variable-resolution model MPAS with a higher-resolution region of 15 km for the simulated typhoons. For Morakot, the associated track and extreme rainfall over southern Taiwan captured by MPAS compared well with the regional WRF simulations. To isolate the influences of various large-scale flows, three modes are filtered out from global reanalysis: the synoptic-scale mode, quasi-biweekly oscillation (QBW) mode, and the Madden-Julian oscillation (MJO) mode. In the absence of QBW or MJO, the simulated Morakot moves westward across Taiwan without the observed north turn after landfall. When the intensity of the MJO mode is increased by 50% in the experiment (MJO+50%), a much earlier northward turn is induced. The simulated Morakot under the observed MJO lies in between MJO+50% and MJO-50% results. The MJO variations also show similar impacts on the track evolution of Typhoon Megi. The wavenumber-1 decompositions of vorticity budget terms are shown to highlight important contributions to the vorticity tendency and typhoon translation with and without the MJO. The northward turn of both typhoons in the presence of the MJO is mainly in response to positive horizontal vorticity advection to the north of the typhoon center. However, vorticity tilting is relatively more important for Morakot due to its slantwise structure. Furthermore, positive vorticity stretching and vertical advection are significant in the vicinity of southern Taiwan due to the effects of the Central Mountain Range and tend to retard the departing Morakot.

原文???core.languages.en_GB???
頁(從 - 到)1691-1716
頁數26
期刊Monthly Weather Review
145
發行號5
DOIs
出版狀態已出版 - 1 5月 2017

指紋

深入研究「Influences of large-scale flow variations on the track evolution of typhoons Morakot (2009) and Megi (2010): Simulations with a global variable-resolution model」主題。共同形成了獨特的指紋。

引用此