The impact of the state of the troposphere on the response to stratospheric heating in a simplified GCM

Simpson, I. R., Blackburn, M., Haigh, J. D. and Sparrow, S. N. (2010) The impact of the state of the troposphere on the response to stratospheric heating in a simplified GCM. Journal of Climate, 23 (23). pp. 6166-6185. ISSN 1520-0442 doi: 10.1175/2010JCLI3792.1

Abstract/Summary

Previous studies have made use of simplified general circulation models (sGCMs) to investigate the atmospheric response to various forcings. In particular, several studies have investigated the tropospheric response to changes in stratospheric temperature. This is potentially relevant for many climate forcings. Here the impact of changing the tropospheric climatology on the modeled response to perturbations in stratospheric temperature is investigated by the introduction of topography into the model and altering the tropospheric jet structure. The results highlight the need for very long integrations so as to determine accurately the magnitude of response. It is found that introducing topography into the model and thus removing the zonally symmetric nature of the model’s boundary conditions reduces the magnitude of response to stratospheric heating. However, this reduction is of comparable size to the variability in the magnitude of response between different ensemble members of the same 5000-day experiment. Investigations into the impact of varying tropospheric jet structure reveal a trend with lower-latitude/narrower jets having a much larger magnitude response to stratospheric heating than higher-latitude/wider jets. The jet structures that respond more strongly to stratospheric heating also exhibit longer time scale variability in their control run simulations, consistent with the idea that a feedback between the eddies and the mean flow is both responsible for the persistence of the control run variability and important in producing the tropospheric response to stratospheric temperature perturbations.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/17549
Identification Number/DOI	10.1175/2010JCLI3792.1
Refereed	Yes
Divisions	Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology Science > School of Mathematical, Physical and Computational Sciences > NCAS
Uncontrolled Keywords	Heating, Stratosphere, Forcing, Topographic effects, Jets, General circulation models, Temperature
Publisher	American Meteorological Society
Publisher Statement	© Copyright 2010 of the American Meteorological Society. The AMS Copyright Policy is available on the AMS web site at http://www.ametsoc.org
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