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 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.

Document Details

Document Type
Pub Defense Publication
Publication Date
Feb 03, 2020
Source ID
10.1029/2019gl085980

Entities

People

  • Dandan Tao
  • Michael M Bell
  • Peter Jan Van Leeuwen
  • Richard Rotunno

Organizations

  • Colorado State University
  • National Center for Atmospheric Research
  • National Science Foundation
  • Office of Naval Research

Tags

Fields of Study

  • Environmental science

Readers

  • Atmospheric Science/Meteorology
  • Ocean-Atmosphere Mesoscale Modeling, Data Assimilation, and Flux Boundary Layers
  • Software Engineering