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 -