TY - JOUR
T1 - Baroclinic modon equilibria on the beta-plane
T2 - Stability and transitions
AU - Kizner, Z.
AU - Berson, D.
AU - Khvoles, R.
PY - 2002/10/10
Y1 - 2002/10/10
N2 - The objective of this work is a numerical study of the stability properties and the evolution of the eastward-travelling baroclinic modons - coherent vortex structures specific to stratified geophysical fluids where differential rotation (the β-effect) is of the essence. In the vortices under study, the initial dependence of the potential vorticity (PV) upon the streamfunction is piecewise-linear, the barotropic component is dipolar, the baroclinic component is circularly symmetric about the vertical axis, and the boundary of the trapped-fluid region (in which the vorticity contours are closed) is a circular cylinder. These modons are shown to be stable for a wide range of parameters. In two- and three-layer fluids, modons of this type are shown to be able to transit to even more durable states, in which the trapped-fluid area is oval in shape and the PV versus streamfunction dependence in this domain is nonlinear. Possible transition mechanisms and linkage between the circular and oval modons are discussed.
AB - The objective of this work is a numerical study of the stability properties and the evolution of the eastward-travelling baroclinic modons - coherent vortex structures specific to stratified geophysical fluids where differential rotation (the β-effect) is of the essence. In the vortices under study, the initial dependence of the potential vorticity (PV) upon the streamfunction is piecewise-linear, the barotropic component is dipolar, the baroclinic component is circularly symmetric about the vertical axis, and the boundary of the trapped-fluid region (in which the vorticity contours are closed) is a circular cylinder. These modons are shown to be stable for a wide range of parameters. In two- and three-layer fluids, modons of this type are shown to be able to transit to even more durable states, in which the trapped-fluid area is oval in shape and the PV versus streamfunction dependence in this domain is nonlinear. Possible transition mechanisms and linkage between the circular and oval modons are discussed.
UR - http://www.scopus.com/inward/record.url?scp=0037057677&partnerID=8YFLogxK
U2 - 10.1017/s0022112002001611
DO - 10.1017/s0022112002001611
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AN - SCOPUS:0037057677
SN - 0022-1120
VL - 468
SP - 239
EP - 270
JO - Journal of Fluid Mechanics
JF - Journal of Fluid Mechanics
ER -