The contrasting climate response to tropical and extratropical energy perturbations

Hawcroft, Matt and Haywood, Jim M. and Collins, Mat and Jones, Andy (2018) The contrasting climate response to tropical and extratropical energy perturbations. Climate Dynamics, 51 (9-10). pp. 3231-3249. ISSN 0930-7575

Abstract

The link between cross-equatorial energy transport, the double-intertropical convergence zone (DI) problem and biases in tropical and extratropical albedo and energy budgets in climate models have been investigated in multiple studies, though DI biases persist in many models. Here, a coupled climate model, HadGEM2-ES, is used to investigate the response to idealised energy perturbations in the tropics and extratropics, in both the northern and southern hemispheres, through the imposition of stratospheric aerosols that reflect incoming radiation. The impact on the tropical climate of high and low latitude forcing strongly contrasts, with large changes in tropical precipitation and modulation of the DI bias when the tropics are cooled as precipitation moves away from the cooled hemisphere. These responses are muted when the extratropics are cooled, as the meridional energy transport anomalies that are excited by these energy budget anomalies are partitioned between the atmosphere and ocean. The results here highlight the persistence of the DI bias in HadGEM2-ES, indicating why little progress has been made in rectifying these problems through many generations of climate models. A highly linear relationship between cross-equatorial atmospheric energy transport, tropical precipitation asymmetry and tropical sea surface temperature biases is also demonstrated, giving some suggestion as to where improvements in these large scale, persistent biases may be achieved.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Permanent restricted access to published version, in accordance with the copyright policy of the publisher.
Faculty/School / Institute/Centre: Current - Institute for Life Sciences and the Environment - Centre for Applied Climate Sciences
Date Deposited: 27 Feb 2019 05:13
Last Modified: 13 Jun 2019 05:16
Uncontrolled Keywords: climate models; energy transport; extratropics; ITCZ; tropics; aerosol; albedo; climate effect; climate modeling; energy budget; extratropical environment; intertropical convergence zone; perturbation; radiation budget; tropical environment
Fields of Research : 04 Earth Sciences > 0401 Atmospheric Sciences > 040107 Meteorology
04 Earth Sciences > 0401 Atmospheric Sciences > 040105 Climatology (excl.Climate Change Processes)
Identification Number or DOI: 10.1007/s00382-018-4076-8
URI: http://eprints.usq.edu.au/id/eprint/35930

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