Vertical structure of anthropogenic zonal-mean atmospheric circulation change

Woollings, T. J. (2008) Vertical structure of anthropogenic zonal-mean atmospheric circulation change. Geophysical Research Letters, 35 (19). L19702. ISSN 0094-8276 doi: 10.1029/2008GL034883

Abstract/Summary

The atmospheric circulation changes predicted by climate models are often described using sea level pressure, which generally shows a strengthening of the mid-latitude westerlies. Recent observed variability is dominated by the Northern Annular Mode (NAM) which is equivalent barotropic, so that wind variations of the same sign are seen at all levels. However, in model predictions of the response to anthropogenic forcing, there is a well-known enhanced warming at low levels over the northern polar cap in winter. This means that there is a strong baroclinic component to the response. The projection of the response onto a NAM-like zonal index varies with height. While at the surface most models project positively onto the zonal index, throughout most of the depth of the troposphere many of the models give negative projections. The response to anthropogenic forcing therefore has a distinctive baroclinic signature which is very different to the NAM

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/1193
Identification Number/DOI	10.1029/2008GL034883
Refereed	Yes
Divisions	Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
Publisher	American Geophysical Union
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