TY - JOUR

T1 - A buoyancy-vorticity wave interaction approach to stratified shear flow

AU - Harnik, Nili

AU - Heifetz, E.

AU - Umurhan, O. M.

AU - Lott, F.

PY - 2008

Y1 - 2008

N2 - Motivated by the success of potential vorticity (PV) thinking for Rossby waves and related shear flow phenomena, this work develops a buoyancy-vorticity formulation of gravity waves in stratified shear How, for which the nonlocality enters in the same way as it does for barotropic/baroclinic shear flows. This formulation provides a time integration scheme that is analogous to the time integration of the quasigeostrophic equations with two, rather than one, prognostic equations, and a diagnostic equation forestream-function through a vorticity inversion. The invertibility of vorticity allows the development of a gravity wave kernel view, which provides a mechanistic rationalization of many aspects of the linear dynamics of stratified shear flow. The resulting kernel formulation is similar to the Rossby-based one obtained for barotropic and baroclinic instability; however, since there are two independent variables - vorticity and buoyancy - there are also two independent kernels at each level. Though having two kernels complicates the picture, the kernels are constructed so that they do not interact with each other at a given level.

AB - Motivated by the success of potential vorticity (PV) thinking for Rossby waves and related shear flow phenomena, this work develops a buoyancy-vorticity formulation of gravity waves in stratified shear How, for which the nonlocality enters in the same way as it does for barotropic/baroclinic shear flows. This formulation provides a time integration scheme that is analogous to the time integration of the quasigeostrophic equations with two, rather than one, prognostic equations, and a diagnostic equation forestream-function through a vorticity inversion. The invertibility of vorticity allows the development of a gravity wave kernel view, which provides a mechanistic rationalization of many aspects of the linear dynamics of stratified shear flow. The resulting kernel formulation is similar to the Rossby-based one obtained for barotropic and baroclinic instability; however, since there are two independent variables - vorticity and buoyancy - there are also two independent kernels at each level. Though having two kernels complicates the picture, the kernels are constructed so that they do not interact with each other at a given level.

UR - http://www.scopus.com/inward/record.url?scp=51749099159&partnerID=8YFLogxK

U2 - 10.1175/2007JAS2610.1

DO - 10.1175/2007JAS2610.1

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AN - SCOPUS:51749099159

SN - 0022-4928

VL - 65

SP - 2615

EP - 2630

JO - Journals of the Atmospheric Sciences

JF - Journals of the Atmospheric Sciences

IS - 8

ER -