Ocean and Atmosphere Storm Tracks: The Role of Eddy Vorticity Forcing
- 1 September 2007
- journal article
- Published by American Meteorological Society in Journal of Physical Oceanography
- Vol. 37 (9), 2267-2289
- https://doi.org/10.1175/jpo3120.1
Abstract
Signatures of eddy variability and vorticity forcing are diagnosed in the atmosphere and ocean from weather center reanalysis and altimetric data broadly covering the same period, 1992–2002. In the atmosphere, there are localized regions of eddy variability referred to as storm tracks. At the entrance of the storm track the eddies grow, providing a downgradient heat flux and accelerating the mean flow eastward. At the exit and downstream of the storm track, the eddies decay and instead provide a westward acceleration. In the ocean, there are similar regions of enhanced eddy variability along the extension of midlatitude boundary currents and the Antarctic Circumpolar Current. Within these regions of high eddy kinetic energy, there are more localized signals of high Eady growth rate and downgradient eddy heat fluxes. As in the atmosphere, there are localized regions in the Southern Ocean where ocean eddies provide statistically significant vorticity forcing, which acts to accelerate the mean flow eastward, provide torques to shift the jet, or decelerate the mean flow. These regions of significant eddy vorticity forcing are often associated with gaps in the topography, suggesting that the ocean jets are being locally steered by topography. The eddy forcing may also act to assist in the separation of boundary currents, although the diagnostics of this study suggest that this contribution is relatively small when compared with the advection of planetary vorticity by the time-mean flow.Keywords
This publication has 34 references indexed in Scilit:
- Storm Track DynamicsJournal of Climate, 2002
- Global high‐resolution mapping of ocean circulation from TOPEX/Poseidon and ERS‐1 and ‐2Journal of Geophysical Research: Oceans, 2000
- Geographical Variability of the First Baroclinic Rossby Radius of DeformationJournal of Physical Oceanography, 1998
- The Southern Ocean Momentum Balance: Evidence for Topographic Effects from Numerical Model Output and Altimeter DataJournal of Physical Oceanography, 1997
- Localized Coupling between Surface and Bottom-Intensified Flow over TopographyJournal of Physical Oceanography, 1997
- The Effects of Orography on Midlatitude Northern Hemisphere Dry ClimatesJournal of Climate, 1992
- On the Existence of Storm-TracksJournal of the Atmospheric Sciences, 1990
- On the Role of Large-Scale Transient Eddies in the Maintenance of the Vorticity and Enstrophy of the Time-Mean Atmospheric FlowJournal of the Atmospheric Sciences, 1981
- An Observational Study of the Northern Hemisphere Wintertime CirculationJournal of the Atmospheric Sciences, 1977
- Long Waves and Cyclone WavesTellus, 1949