A pan-African convection-permitting regional climate simulation with the Met Office Unified Model: CP4-Africa

Stratton, Rachel A.; Senior, Catherine A.; Vosper, Simon B.; Folwell, Sonja S.; Boutle, Ian A.; Earnshaw, Paul D.; Kendon, Elizabeth; Lock, Adrian P.; Malcolm, Andrew; Manners, James; Morcrette, Cyril J.; Short, Christopher; Stirling, Alison J.; Taylor, Christopher M. ORCID: https://orcid.org/0000-0002-0120-3198; Tucker, Simon; Webster, Stuart; Wilkinson, Jonathan M.. 2018 A pan-African convection-permitting regional climate simulation with the Met Office Unified Model: CP4-Africa. Journal of Climate, 31 (9). 10.1175/JCLI-D-17-0503.1

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Official URL: https://doi.org/10.1175/JCLI-D-17-0503.1

Abstract/Summary

A convection-permitting multi-year regional climate simulation using the Met Office Unified Model has been run for the first time on an Africa-wide domain. The model has been run as part of the Future Climate for Africa (FCFA) IMPALA (Improving Model Processes for African cLimAte) project and its configuration, domain and forcing data are described here in detail. The model (CP4-Africa) uses a 4.5km horizontal grid spacing at the equator and is run without a convection parametrization, nested within a global atmospheric model driven by observations at the sea-surface which does include a convection scheme. An additional regional simulation, with identical resolution and physical parametrizations to the global model, but with the domain, land surface and aerosol climatologies of the CP4-Africa model, has been run to aid understanding of the differences between the CP4-Africa and global model, in particular to isolate the impact of the convection parametrization and resolution. The effect of enforcing moisture conservation in the CP4-Africa model is described and its impact on reducing extreme precipitation values is assessed. Preliminary results from the first 5 years of the CP4-Africa simulation show substantial improvements in JJA average rainfall compared to the parameterized convection models, with most notably a reduction in the persistent dry bias in West Africa - giving an indication of the benefits to be gained from running a convection-permitting simulation over the whole African continent.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	10.1175/JCLI-D-17-0503.1
UKCEH and CEH Sections/Science Areas:	Hydro-climate Risks (Science Area 2017-)
ISSN:	0894-8755
NORA Subject Terms:	Meteorology and Climatology
Date made live:	06 Feb 2018 15:18 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/519083

Item Type:

Publication - Article

Digital Object Identifier (DOI):

10.1175/JCLI-D-17-0503.1

UKCEH and CEH Sections/Science Areas:

Hydro-climate Risks (Science Area 2017-)

ISSN:

0894-8755

NORA Subject Terms:

Meteorology and Climatology

Date made live:

06 Feb 2018 15:18 +0 (UTC)