Inclusion of mountain wave-induced cooling for the formation of PSCs over the Antarctic Peninsula in a chemistry-climate model

Orr, A. ORCID: https://orcid.org/0000-0001-5111-8402; Hosking, J.S. ORCID: https://orcid.org/0000-0002-3646-3504; Hoffmann, L.; Keeble, J.; Dean, S.M.; Roscoe, H.K.; Abraham, N.L.; Vosper, S.; Braesicke, P.. 2015 Inclusion of mountain wave-induced cooling for the formation of PSCs over the Antarctic Peninsula in a chemistry-climate model. Atmospheric Chemistry and Physics, 15 (2). 1071-1086. 10.5194/acp-15-1071-2015

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Abstract/Summary

An important source of polar stratospheric clouds (PSCs), which play a crucial role in controlling polar stratospheric ozone depletion, is from the temperature fluctuations induced by mountain waves. However, this formation mechanism is usually missing in chemistry–climate models because these temperature fluctuations are neither resolved nor parameterised. Here, we investigate the representation of stratospheric mountain-wave-induced temperature fluctuations by the UK Met Office Unified Model (UM) at climate scale and mesoscale against Atmospheric Infrared Sounder satellite observations for three case studies over the Antarctic Peninsula. At a high horizontal resolution (4 km) the regional mesoscale configuration of the UM correctly simulates the magnitude, timing, and location of the measured temperature fluctuations. By comparison, at a low horizontal resolution (2.5° × 3.75°) the global climate configuration fails to resolve such disturbances. However, it is demonstrated that the temperature fluctuations computed by a mountain wave parameterisation scheme inserted into the climate configuration (which computes the temperature fluctuations due to unresolved mountain waves) are in relatively good agreement with the mesoscale configuration responses for two of the three case studies. The parameterisation was used to include the simulation of mountain-wave-induced PSCs in the global chemistry–climate configuration of the UM. A subsequent sensitivity study demonstrated that regional PSCs increased by up to 50% during July over the Antarctic Peninsula following the inclusion of the local mountain-wave-induced cooling phase.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	10.5194/acp-15-1071-2015
Programmes:	BAS Programmes > Polar Science for Planet Earth (2009 - ) > Climate
ISSN:	1680-7316
Date made live:	04 Jun 2014 15:00 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/507354

Item Type:

Publication - Article

Digital Object Identifier (DOI):

10.5194/acp-15-1071-2015

Programmes:

BAS Programmes > Polar Science for Planet Earth (2009 - ) > Climate

ISSN:

1680-7316

Date made live:

04 Jun 2014 15:00 +0 (UTC)

URI:

https://nora.nerc.ac.uk/id/eprint/507354