Why Do the Maximum Intensities in Modeled Tropical Cyclones Vary Under the Same Environmental Conditions?

Abstract In this study w e explored why the different initial tropical cyclone structures can result in different steady‐state maximum intensities in model simulations with the same environmental conditions. We discovered a linear relationsh ip between the radius of maximum wind (rm) and the absolut...

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Bibliographic Details
Main Authors: Dandan Tao, Michael Bell, Richard Rotunno, Peter Jan vanLeeuwen
Format: Article
Language:English
Published: Wiley 2020-02-01
Series:Geophysical Research Letters
Subjects:
Online Access:https://doi.org/10.1029/2019GL085980
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Summary:Abstract In this study w e explored why the different initial tropical cyclone structures can result in different steady‐state maximum intensities in model simulations with the same environmental conditions. We discovered a linear relationsh ip between the radius of maximum wind (rm) and the absolute angular momentum that passes through rm (Mm) in the model simulated steady‐state tropical cyclones that rm = aMm+b. This nonnegligible intercept b is found to be the key to making a steady‐state storm with a larger Mm more intense. The sensitivity experiments show that this nonzero b results mainly from horizontal turbulent mixing and decreases with decreased horizontal mixing. Using this linear relationship from the simulations, it is also found that the degree of supergradient wind is a function of Mm as well as the turbulent mixing length such that both a larger Mm and/or a reduced turbulent mixing length result in larger supergradient winds.
ISSN:0094-8276
1944-8007