Article Type:
Research Article

Frontal Equilibration by Frictional Processes

Richard D. Twigg Headquarters, U.S. Air Force, Directorate of Weather, Washington, D.C.

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Peter R. Bannon Department of Meteorology, The Pennsylvania State University, University Park, Pennsylvania

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Print Publication:
01 Mar 1998
DOI:
https://doi.org/10.1175/1520-0469(1998)055<1084:FEBFP>2.0.CO;2
Page(s):
1084–1087
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Abstract

The effect of friction on frontogenesis driven by a stretching deformation field is studied analytically in both a quasigeostrophic and a semigeostrophic framework for a semi-infinite, adiabatic, Boussinesq fluid on an f plane. Friction is incorporated into the model in terms of a boundary layer pumping term.

The solutions demonstrate that the effect of friction is frontolytic. The quasigeostrophic fronts always equilibrate at a finite horizontal scale. The semigeostrophic fronts equilibrate at a finite horizontal scale if the strength of the frontogenesis is below a threshold value. Above this threshold, the front is predicted to collapse to a discontinuity in its thermal and momentum fields.

Corresponding author address: Dr. Peter R. Bannon, Department of Meteorology, The Pennsylvania State University, 503 Walker Building, University Park, PA 16802-5013.

Email: bannon@ems.psu.edu

Abstract

The effect of friction on frontogenesis driven by a stretching deformation field is studied analytically in both a quasigeostrophic and a semigeostrophic framework for a semi-infinite, adiabatic, Boussinesq fluid on an f plane. Friction is incorporated into the model in terms of a boundary layer pumping term.

The solutions demonstrate that the effect of friction is frontolytic. The quasigeostrophic fronts always equilibrate at a finite horizontal scale. The semigeostrophic fronts equilibrate at a finite horizontal scale if the strength of the frontogenesis is below a threshold value. Above this threshold, the front is predicted to collapse to a discontinuity in its thermal and momentum fields.

Corresponding author address: Dr. Peter R. Bannon, Department of Meteorology, The Pennsylvania State University, 503 Walker Building, University Park, PA 16802-5013.

Email: bannon@ems.psu.edu

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