Intrinsic dynamics and long‐term evolution of a convectively generated oceanic vortex in the Greenland Sea

Abstract

[1] Nonstationary dynamics, realistic long-term evolution, and influence on local convection characterizing an oceanic vortex similar to those observed in the central Greenland Sea were investigated using in situ data, a hierarchy of numerical models, and an analytical theory. A nonhydrostatic model for the simulation of convective plumes was nested into a regional ocean-ice model forced and initialized by a global, atmosphere/ocean/ice model. In the central Greenland Sea, water masses similar to those observed in a convectively-generated vortex and a corresponding numerically reconstructed 3D velocity were imposed in the non-hydrostatic model. Under atmospheric/ oceanic realistic conditions and forcing, the simulated vortex evolved as an almost circular, nonstationary, longlived, predominantly anticyclonically rotating feature. As time elapsed, it detached from the sea surface and became an intermediate vortex, which influenced the local convective preconditioning. Its inertial pulsations, shape, and velocity structure closely resemble corresponding characteristics of recently discovered theoretic nonstationary anticyclones.Citation: Rubino, A., A. Androssov, and S. Dotsenko (2007), Intrinsic dynamics and long-term evolution of a convectively generated

Baroclinic instability and submesoscale eddy formation in weakly stratified oceans under cooling

“…[55] Although some model studies recently discussed the formation and evolution processes of the SCVs [e.g., Rubino et al, 2007;Oliver et al, 2008], their scales were prescribed, and what determines their scales (or what are their origins) was unknown. Many similarities mentioned above, including the scale, imply that the anticyclonic eddies are a possible candidate for the origin of the SCVs in weakly stratified polar (subarctic) oceans.…”

“…Oliver et al [2008] pointed to the importance of bottom topography as well as background hydrography to interpret the observed behaviors of SCVs. Rubino et al [2007] discussed the longevity of the SCVs in the Greenland Sea, based on the nested model experiments driven by realistic forcings. In these studies, however, the model settings of a homogeneous dense water patch (cylinder) preloaded in the stratified ocean are not sufficient to discuss the origins of SCVs.…”

“…[6] Recent studies focused on the features (generation, monopolarity, longevity) of the SCVs observed in the convective regions [Dewar, 2002;Lilly et al, 2003;Rubino et al, 2007;Oliver et al, 2008]. Some suggested that baroclinic instability can be a candidate for their generation [Dewar, 2002;Lilly et al, 2003].…”

On the Geostrophic Adjustment of an Isolated Lens: Dependence on Burger Number and Initial Geometry*

“…Reviews of the classic adjustment problem, as well as many of its variants, may be found, for example, in Blumen (1972), Gill (1982), McWilliams (1985), and Flierl (1987). Subsequent studies have continued to relate the basic principles to a range of oceanographic phenomena, including the adjustment of density fronts and their associated meanders (e.g., Ou 1984;van Heijst 1985;Garvine 1987;Spall 1995;Blumen and Wu 1995), the ocean response to storms (e.g., Geisler 1970;Price 1981), the dynamics of dense water outflows (e.g., Price and O'Neil Baringer 1994;Cenedese et al 2004), and ocean convection (e.g., Killworth 1979;Hermann and Owens 1993;Whitehead et al 1996;Rubino et al 2007), to name a few.…”

“…Relevant to the present study, Saunders (1973) as well as Rubino and Brandt (2003) conducted experiments to test the simplest form of geostrophic adjustment in which they removed a thin-walled cylinder that separated higher and lower density fluids in a rotating cylindrical tank. Relevant to the present study, Saunders (1973) as well as Rubino and Brandt (2003) conducted experiments to test the simplest form of geostrophic adjustment in which they removed a thin-walled cylinder that separated higher and lower density fluids in a rotating cylindrical tank.…”