Investigation of the positive interaction between the primary and secondary circulation and the roles of different types of precipitation in tropical cyclone formation
type: CreativeWork
description: Our understanding of tropical cyclogenesis, one of the greatest mysteries in tropical meteorology, has advanced significantly in the past few decades, partly owing to the availability of satellite data and high-resolution numerical model simulations. This research investigates the coupling among the primary circulation, secondary circulation and precipitation during tropical cyclogenesis through analyses of satellite data and cloud-representing numerical model simulations. Previous studies have emphasized the importance of the positive feedback between the ocean surface heat fluxes and the primary circulation, but our analyses based on high-resolution numerical model simulations suggest that the local evaporation and its positive interaction with the primary circulation may not be as important as generally appreciated for tropical cyclone development. In fact, we demonstrate that an increase in the fractional contribution by the inward moisture flux with the storm intensification implies the importance of the positive feedback among the primary circulation, the secondary circulation, and convection for tropical cyclone development. Convection near the storm center feeds off moisture converging from large radii, and the release of latent heat concentrated near the circulation center then drives the overturning secondary circulation, increases the low-level moisture convergence, and intensifies the tangential circulation. We further examine the precipitation evolution during tropical cyclone formation and explored the role of different types of precipitation. Specifically, we quantified the frequency occurrence of stratiform precipitation, shallow convection, mid-level convection (i.e., congestus) and deep convection as well as their contributions to the total precipitation using precipitation and cloud-type retrievals from the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR). Precipitation increases substantially within 36 h before genesis. Stratif…
abstract: Our understanding of tropical cyclogenesis, one of the greatest mysteries in tropical meteorology, has advanced significantly in the past few decades, partly owing to the availability of satellite data and high-resolution numerical model simulations. This research investigates the coupling among the primary circulation, secondary circulation and precipitation during tropical cyclogenesis through analyses of satellite data and cloud-representing numerical model simulations. Previous studies have emphasized the importance of the positive feedback between the ocean surface heat fluxes and the primary circulation, but our analyses based on high-resolution numerical model simulations suggest that the local evaporation and its positive interaction with the primary circulation may not be as important as generally appreciated for tropical cyclone development. In fact, we demonstrate that an increase in the fractional contribution by the inward moisture flux with the storm intensification implies the importance of the positive feedback among the primary circulation, the secondary circulation, and convection for tropical cyclone development. Convection near the storm center feeds off moisture converging from large radii, and the release of latent heat concentrated near the circulation center then drives the overturning secondary circulation, increases the low-level moisture convergence, and intensifies the tangential circulation. We further examine the precipitation evolution during tropical cyclone formation and explored the role of different types of precipitation. Specifically, we quantified the frequency occurrence of stratiform precipitation, shallow convection, mid-level convection (i.e., congestus) and deep convection as well as their contributions to the total precipitation using precipitation and cloud-type retrievals from the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR). Precipitation increases substantially within 36 h before genesis. Stratif…
author: Fritz, Cody Lee
language: en
keywords: Tropical cyclones, Mass fluxes/transport, Moisture budget, Mesoscale models, Tropical cyclogenesis, Cloud evolution, Precipitation
date published: 2017-08-10T20:33:00Z
date modified: 2026-07-22T22:24:34Z
provider: University of Illinois - Urbana-Champaign
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Illinois at Urbana-Champaign

PropertyValue
property ID: Handle
value: http://hdl.handle.net/2142/97719