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2017/03/17 14:00 Dr. Iam-Fei Pun（Department of Atmospheric Sciences, NTU）
Seminar
Poster： ╱ Post date：2017-03-14NCU IHOS Seminar Announcement
Speaker：Dr. Iam-Fei Pun
Place：S-325, Science Building 1
Abstract：
Title：Influence of the size of Supertyphoon Megi (2010) on SST cooling
Speaker：Dr. Iam-Fei Pun
Department of Atmospheric Sciences, NTU
Time：03/17（Fri.）14：00
Place：S-325, Science Building 1
Abstract：
Supertyphoon Megi (2010) left behind two very contrasting SST cooling patterns between the western North Pacific gyre and the South China Sea. Other than the well-known factors (e.g. translation speed and pre-existing ocean thermal condition), we discovered that the size of Megi plays a non-negligible role. In this study, we seek to address the storm size issue and quantify its impact on Megi-induced SST cooling. Based on numerical experiments, we found that if without Megi’s size increase over the South China Sea, the SST cooling amount would reduce by 28%, the right bias would reduce by 12%, and the width of the cooling would reduce by 34%. Furthermore, we also found that the SST cooling is linearly dependent on various wind radii (i.e. 64 kt, 50 kt and 34 kt) with different rates. The SST cooling is most sensitive to the radius of 64 kt (R64) with the rate of 0.0273 °C km-1, which decreases with wind speed (R50= 0.0058 °C km-1 and R34= 0.0032 °C km-1).
In addition, we also show that the size of Megi over the South China Sea significantly lowers the non-dimensional translation speed (S = 1.5), due to increase in residence time. This indicates that Megi is roughly resonant with the inertial current, which partially explains the strong SST cooling. Finally, it is found that curvature of Megi contributes about 11% of cooling over the South China Sea too.
Last modification time：2017-03-14 AM 9:36
