Equatorial superrotation in Held and Suarez like flows with weak equator-to-pole surface temperature gradient

Polichtchouk, I. and Cho, J. Y.-K. (2016) Equatorial superrotation in Held and Suarez like flows with weak equator-to-pole surface temperature gradient. Quarterly Journal of the Royal Meteorological Society, 142 (696). pp. 1528-1540. ISSN 1477-870X doi: 10.1002/qj.2755

Abstract/Summary

Equatorial superrotation under zonally symmetric thermal forcing is investigated in a set-up close to that of the classic Held and Suarez set-up. In contrast to the behaviour in the classic set-up, a transition to equatorial superrotation occurs when the equator-to-pole surface equilibrium entropy gradient is weakened. Two factors contribute to this transition: (i) the reduction of breaking Rossby waves from the midlatitudes that decelerate the equatorial flow and (ii) the presence of barotropic instability in the equatorial region, providing stirring to accelerate the equatorial flow. In the latter, Kelvin waves excited by instability near the Equator generate and maintain the superrotation. However, the superrotation is unphysically enhanced if simulations are underresolved and/or overdissipated.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/75476
Item Type	Article
Refereed	Yes
Divisions	Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
Publisher	Royal Meteorological Society
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