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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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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author Dandan Tao
Michael Bell
Richard Rotunno
Peter Jan vanLeeuwen
author_facet Dandan Tao
Michael Bell
Richard Rotunno
Peter Jan vanLeeuwen
author_sort Dandan Tao
collection DOAJ
description 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.
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publishDate 2020-02-01
publisher Wiley
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series Geophysical Research Letters
spelling doaj-art-4ea760a9a76d4d49aeb85b7e587c7a792025-08-20T02:31:27ZengWileyGeophysical Research Letters0094-82761944-80072020-02-01473n/an/a10.1029/2019GL085980Why Do the Maximum Intensities in Modeled Tropical Cyclones Vary Under the Same Environmental Conditions?Dandan Tao0Michael Bell1Richard Rotunno2Peter Jan vanLeeuwen3Department of Atmospheric Science Colorado State University Fort Collins CO USADepartment of Atmospheric Science Colorado State University Fort Collins CO USANational Center for Atmospheric Research Boulder CO USADepartment of Atmospheric Science Colorado State University Fort Collins CO USAAbstract 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.https://doi.org/10.1029/2019GL085980maximum potential intensityaxisymmetric tropical cyclone theorylinear relationshipangular momentum
spellingShingle Dandan Tao
Michael Bell
Richard Rotunno
Peter Jan vanLeeuwen
Why Do the Maximum Intensities in Modeled Tropical Cyclones Vary Under the Same Environmental Conditions?
Geophysical Research Letters
maximum potential intensity
axisymmetric tropical cyclone theory
linear relationship
angular momentum
title Why Do the Maximum Intensities in Modeled Tropical Cyclones Vary Under the Same Environmental Conditions?
title_full Why Do the Maximum Intensities in Modeled Tropical Cyclones Vary Under the Same Environmental Conditions?
title_fullStr Why Do the Maximum Intensities in Modeled Tropical Cyclones Vary Under the Same Environmental Conditions?
title_full_unstemmed Why Do the Maximum Intensities in Modeled Tropical Cyclones Vary Under the Same Environmental Conditions?
title_short Why Do the Maximum Intensities in Modeled Tropical Cyclones Vary Under the Same Environmental Conditions?
title_sort why do the maximum intensities in modeled tropical cyclones vary under the same environmental conditions
topic maximum potential intensity
axisymmetric tropical cyclone theory
linear relationship
angular momentum
url https://doi.org/10.1029/2019GL085980
work_keys_str_mv AT dandantao whydothemaximumintensitiesinmodeledtropicalcyclonesvaryunderthesameenvironmentalconditions
AT michaelbell whydothemaximumintensitiesinmodeledtropicalcyclonesvaryunderthesameenvironmentalconditions
AT richardrotunno whydothemaximumintensitiesinmodeledtropicalcyclonesvaryunderthesameenvironmentalconditions
AT peterjanvanleeuwen whydothemaximumintensitiesinmodeledtropicalcyclonesvaryunderthesameenvironmentalconditions