Stratospheric communication of El Niño teleconnections to European winter

Bell, C. J., Gray, L. J., Charlton-Perez, A. J., Joshi, M. M. ORCID: https://orcid.org/0000-0002-2948-2811 and Scaife, A. A. (2009) Stratospheric communication of El Niño teleconnections to European winter. Journal of Climate, 22 (15). pp. 4083-4096. ISSN 0894-8755

Full text not available from this repository. (Request a copy)

Abstract

The stratospheric role in the European winter surface climate response to El Niño–Southern Oscillation sea surface temperature forcing is investigated using an intermediate general circulation model with a well-resolved stratosphere. Under El Niño conditions, both the modeled tropospheric and stratospheric mean-state circulation changes correspond well to the observed “canonical” responses of a late winter negative North Atlantic Oscillation and a strongly weakened polar vortex, respectively. The variability of the polar vortex is modulated by an increase in frequency of stratospheric sudden warming events throughout all winter months. The potential role of this stratospheric response in the tropical Pacific–European teleconnection is investigated by sensitivity experiments in which the mean state and variability of the stratosphere are degraded. As a result, the observed stratospheric response to El Niño is suppressed and the mean sea level pressure response fails to resemble the temporal and spatial evolution of the observations. The results suggest that the stratosphere plays an active role in the European response to El Niño. A saturation mechanism whereby for the strongest El Niño events tropospheric forcing dominates the European response is suggested. This is examined by means of a sensitivity test and it is shown that under large El Niño forcing the European response is insensitive to stratospheric representation.

Item Type: Article
Uncontrolled Keywords: sdg 13 - climate action ,/dk/atira/pure/sustainabledevelopmentgoals/climate_action
Faculty \ School: University of East Anglia Research Groups/Centres > Theme - ClimateUEA
Faculty of Science > School of Environmental Sciences
UEA Research Groups: Faculty of Science > Research Groups > Climatic Research Unit
Faculty of Science > Research Groups > Centre for Ocean and Atmospheric Sciences
University of East Anglia Schools > Faculty of Science > Tyndall Centre for Climate Change Research
Faculty of Science > Research Centres > Tyndall Centre for Climate Change Research
Depositing User: Rhiannon Harvey
Date Deposited: 01 Feb 2012 11:51
Last Modified: 15 Jun 2023 14:30
URI: https://ueaeprints.uea.ac.uk/id/eprint/36704
DOI: 10.1175/2009JCLI2717.1

Actions (login required)

View Item View Item