Stratospheric ozone depletion: a key driver of recent precipitation trends in South Eastern South America

Gonzalez, P. L. M. ORCID: https://orcid.org/0000-0003-0154-0087, Polvani, L. M., Seager, R. and Correa, G. J. P. (2014) Stratospheric ozone depletion: a key driver of recent precipitation trends in South Eastern South America. Climate Dynamics, 42 (7). pp. 1775-1792. ISSN 0930-7575 doi: 10.1007/s00382-013-1777-x

Abstract/Summary

On a hemispheric scale, it is now well established that stratospheric ozone depletion has been the principal driver of externally forced atmospheric circulation changes south of the Equator in the last decades of the 20th Century. The impact of ozone depletion has been felt over the entire hemisphere, as reflected in the poleward drift of the midlatitude jet, the southward expansion of the summertime Hadley cell and accompanying precipitation trends deep into the subtropics. On a regional scale, however, surface impacts directly attributable to ozone depletion have yet to be identified. In this paper we focus on South Eastern South America (SESA), a region that has exhibited one of the largest wetting trends during the 20th Century. We study the impact of ozone depletion on SESA precipitation using output from 6 different climate models, spanning a wide range of complexity. In all cases we contrast pairs of model integrations with and without ozone depletion, but with all other forcings identically specified. This allows for unambiguous attribution of the computed precipitation trends. All 6 climate models consistently reveal that stratospheric ozone depletion results in a significant wetting of SESA over the period 1960--1999. Taken as a whole, these model results strongly suggest that the impact of ozone depletion on SESA precipitation has been as large as, and quite possibly larger than, the one caused by increasing greenhouse gases over the same period.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/85687
Item Type	Article
Refereed	Yes
Divisions	Science > School of Mathematical, Physical and Computational Sciences > NCAS Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
Publisher	Springer
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