Identification

Title

The role of momentum transfer in tropical cyclogenesis: Insights from a single-column model

Abstract

A step not fully understood in tropical cyclogenesis is the development of a surface cyclone, which is often preceded by a midlevel cyclone. This paper presents a single-column model to study the role of the transfer of tangential momentum in generating an initial surface cyclone. To isolate momentum transfer factors from thermodynamic factors, diabatic heating is set to be steady. The investigation starts without considering surface friction. The momentum transfer is decomposed into the transport by the vortex-scale circulation and by convection. The convective momentum transport (cumulus friction), when parameterized as a vertical eddy diffusion, leads to a vertical spectral truncation that permits an analytical solution of the single-column model. The analytical solution shows that the production of barotropic vorticity by the vortex-scale circulation is crucial for surface cyclone formation, and cumulus friction plays a dual role. Cumulus friction can enhance the downward momentum transfer, but when the eddy diffusion is too strong, the vortex-scale circulation is too damped to produce a significant barotropic cyclone. Between these two extremes lies an optimal eddy diffusivity that maximizes the growth rate of the surface cyclone. Finally, we add surface friction to the single-column model. Using scale analysis, we identify a critical vortex Rossby number above which surface friction becomes nonnegligible and significantly damps the development of the surface cyclone.

Resource type

document

Resource locator

Unique resource identifier

code

https://n2t.net/ark:/85065/d71z48s7

codeSpace

Dataset language

eng

Spatial reference system

code identifying the spatial reference system

Classification of spatial data and services

Topic category

geoscientificInformation

Keywords

Keyword set

keyword value

Text

originating controlled vocabulary

title

Resource Type

reference date

date type

publication

effective date

2016-01-01T00:00:00Z

Geographic location

West bounding longitude

East bounding longitude

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South bounding latitude

Temporal reference

Temporal extent

Begin position

End position

Dataset reference date

date type

publication

effective date

2025-03-01T00:00:00Z

Frequency of update

Quality and validity

Lineage

Conformity

Data format

name of format

version of format

Constraints related to access and use

Constraint set

Use constraints

Limitations on public access

None

Responsible organisations

Responsible party

contact position

OpenSky Support

organisation name

UCAR/NCAR - Library

full postal address

PO Box 3000

Boulder

80307-3000

email address

opensky@ucar.edu

web address

http://opensky.ucar.edu/

name: homepage

responsible party role

pointOfContact

Metadata on metadata

Metadata point of contact