Rossby wave breaking, microbreaking, filamentation, and secondary vortex formation: The dynamics of a perturbed vortex

Journal Article · Sun Mar 15 04:00:00 EST 1992 · Journal of the Atmospheric Sciences; (United States)

DOI:https://doi.org/10.1175/1520-0469(1992)049<0462:RWBMFA>2.0.CO;2· OSTI ID:5644523

Polvani, L M ^[1]; Plumb, R A ^[2]

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1. Columbia Univ., New York, NY (United States)
2. Massachusetts Institute of Technology, Cambridge, MA (United States)

The behavior of an isolated vortex perturbed by topographically forced Rossby waves is studied using the method of Contour Dynamics. For a single-contour vortex a distinct forcing threshold exists above which the wave break in a dynamically significant way, leading to a disruption of the vortex. This breaking is distinguished from the process of weak filamentary breaking described by Dritschel and classified here as microbreaking; the latter occurs in nondivergent flow even at very small forcing amplitudes but does not affect the vortex in a substantial manner. In cases with finite Rossby deformation radius (comparable with the vortex radius) neither breaking nor microbreaking occurs below the forcing threshold. In common with previous studies using high-resolution spectral models, the vortex is not diluted by intrusion of outside air, except during remerger with a secondary vortex shed previously from the main vortex during a breaking event. The kinematics of the breaking process and of the vortex interior and the morphology of material ejected from the vortex are described. When the Rossby radius is finite there is substantial mixing in the deep interior of the vortex, even when the vortex is only mildly disturbed, Implications for the stratospheric polar vortex are discussed. 31 refs., 21 figs., 1 tab.

• OSTI ID: 5644523
• Journal Information: Journal of the Atmospheric Sciences; (United States), Journal Name: Journal of the Atmospheric Sciences; (United States) Vol. 49:6; ISSN 0022-4928; ISSN JAHSAK
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540110*
540120 -- Environment
Atmospheric-- Chemicals Monitoring &amp; Transport-- (1990-)
ATMOSPHERIC CHEMISTRY
ATMOSPHERIC CIRCULATION
CHEMISTRY
DISTURBANCES
EARTH ATMOSPHERE
FLUID FLOW
FUNCTIONS
GRAVITY WAVES
METEOROLOGY
MORPHOLOGY
STRATOSPHERE
VORTEX FLOW
WAVE FUNCTIONS
WAVE PROPAGATION