Article Type:
Research Article

Lower-Tropospheric Height Tendencies Associated with the Shearwise and Transverse Components of Quasigeostrophic Vertical Motion

Jonathan E. Martin Department of Atmospheric and Oceanic Sciences, University of Wisconsin—Madison, Madison, Wisconsin

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Print Publication:
01 Jul 2007
DOI:
https://doi.org/10.1175/MWR3416.1
Page(s):
2803–2809
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Abstract

The recent suggestion that lower-tropospheric cyclogenesis is predominantly a result of column stretching associated with the updraft portion of the shearwise quasigeostrophic (QG) vertical motion is quantified through direct calculation of 900-hPa height tendencies via the QG vorticity equation. Comparison of the separate lower-tropospheric height tendencies associated with the shearwise and transverse portions of QG omega in a robust cyclogenesis event demonstrates that the shearwise updraft drives the largest part (>80%) of the cyclogenetic height falls at least through the end of the mature stage of the life cycle. The lower-tropospheric height falls and vorticity production near the sea level pressure minimum of the occluded surface cyclone are driven nearly equally by shearwise and transverse updrafts.

Corresponding author address: Jonathan E. Martin, Department of Atmospheric and Oceanic Sciences, University of Wisconsin—Madison, 1225 W. Dayton St., Madison, WI 53706. Email: jemarti1@wisc.edu

Abstract

The recent suggestion that lower-tropospheric cyclogenesis is predominantly a result of column stretching associated with the updraft portion of the shearwise quasigeostrophic (QG) vertical motion is quantified through direct calculation of 900-hPa height tendencies via the QG vorticity equation. Comparison of the separate lower-tropospheric height tendencies associated with the shearwise and transverse portions of QG omega in a robust cyclogenesis event demonstrates that the shearwise updraft drives the largest part (>80%) of the cyclogenetic height falls at least through the end of the mature stage of the life cycle. The lower-tropospheric height falls and vorticity production near the sea level pressure minimum of the occluded surface cyclone are driven nearly equally by shearwise and transverse updrafts.

Corresponding author address: Jonathan E. Martin, Department of Atmospheric and Oceanic Sciences, University of Wisconsin—Madison, 1225 W. Dayton St., Madison, WI 53706. Email: jemarti1@wisc.edu

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  • Hoskins, B. J., I. Draghici, and H. C. Davies, 1978: A new look at the ω-equation. Quart. J. Roy. Meteor. Soc., 104 , 31–38.

  • Martin, J. E., 1998: On the deformation term in the quasigeostrophic omega equation. Mon. Wea. Rev., 126 , 2000–2007.

  • Martin, J. E., 1999: Quasigeostrophic forcing for ascent in the occluded sector of cyclones and the trowal airstream. Mon. Wea. Rev., 127 , 70–88.

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  • Martin, J. E., 2006: The role of shearwise and transverse quasigeostrophic vertical motions in the midlatitude cyclone life cycle. Mon. Wea. Rev., 134 , 1174–1193.

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  • Sutcliffe, R. C., 1947: A contribution to the problem of development. Quart. J. Roy. Meteor. Soc., 73 , 370–383.

  • Trenberth, K. E., 1978: On the interpretation of the diagnostic quasi-geostrophic omega equation. Mon. Wea. Rev., 106 , 131–137.

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