The Role of Stationary Eddies in Shaping Midlatitude Storm Tracks
METADATA ONLY
Loading...
Author / Creator
Date
2013
Publication Type
Journal Article
ETH Bibliography
yes
Citations
Altmetric
METADATA ONLY
Data
Rights / License
Abstract
Transient and stationary eddies shape the extratropical climate through their transport of heat, moisture, and momentum. In the zonal mean, the transports by transient eddies dominate over those by stationary eddies, but this is not necessarily the case locally. In particular, in storm-track entrance and exit regions during winter, stationary eddies and their interactions with the mean flow dominate the atmospheric energy transport. Here it is shown that stationary eddies can shape storm tracks and control where they terminate by modifying local baroclinicity. Simulations with an idealized aquaplanet GCM show that zonally localized surface heating alone (e.g., ocean heat flux convergence) gives rise to storm tracks, which have a well-defined length scale that is similar to that of Earth's storm tracks. The storm tracks terminate downstream of the surface heating even in the absence of continents, at a distance controlled by the stationary Rossby wavelength scale. Stationary eddies play a dual role: within about half a Rossby wavelength downstream of the heating region, stationary eddy energy fluxes increase the baroclinicity and therefore contribute to energizing the storm track; farther downstream, enhanced poleward and upward energy transport by stationary eddies reduces the baroclinicity by reducing the meridional temperature gradients and enhancing the static stability. Transports both of sensible and latent heat (water vapor) play important roles in determining where storm tracks terminate.
Permanent link
Publication status
published
External links
Editor
Book title
Journal / series
Volume
70 (8)
Pages / Article No.
2596 - 2613
Publisher
American Meteorological Society
Event
Edition / version
Methods
Geographic location
Date collected
Date created
Subject
Baroclinic flows; Stationary waves; Eddies; Storm tracks; Mass fluxes/transport; Moisture/Moisture budget
Organisational unit
03991 - Schneider, Tapio (ehemalig)
Notes
Received 7 March 2012, Final Form 28 February 2013.