Effect of model resolution on a regional climate model simulation over southeast Australia

Handle URI:
http://hdl.handle.net/10754/555783
Title:
Effect of model resolution on a regional climate model simulation over southeast Australia
Authors:
Evans, J. P. ( 0000-0003-1776-3429 ) ; McCabe, Matthew ( 0000-0002-1279-5272 )
Abstract:
Dynamically downscaling climate projections from global climate models (GCMs) for use in impacts and adaptation research has become a common practice in recent years. In this study, the CSIRO Mk3.5 GCM is downscaled using the Weather Research and Forecasting (WRF) regional climate model (RCM) to medium (50 km) and high (10 km) resolution over southeast Australia. The influence of model resolution on the present-day (1985 to 2009) modelled regional climate and projected future (2075 to 2099) changes are examined for both mean climate and extreme precipitation characteristics. Increasing model resolution tended to improve the simulation of present day climate, with larger improvements in areas affected by mountains and coastlines. Examination of circumstances under which increasing the resolution decreased performance revealed an error in the GCM circulation, the effects of which had been masked by the coarse GCM topography. Resolution modifications to projected changes were largest in regions with strong topographic and coastline influences, and can be large enough to change the sign of the climate change projected by the GCM. Known physical mechanisms for these changes included orographic uplift and low-level blocking of air-masses caused by mountains. In terms of precipitation extremes, the GCM projects increases in extremes even when the projected change in the mean was a decrease: but this was not always true for the higher resolution models. Thus, while the higher resolution RCM climate projections often concur with the GCM projections, there are times and places where they differ significantly due to their better representation of physical processes. It should also be noted that the model resolution can modify precipitation characteristics beyond just its mean value.
KAUST Department:
Water Desalination and Reuse Research Center (WDRC); Biological and Environmental Sciences and Engineering (BESE) Division
Citation:
Effect of model resolution on a regional climate model simulation over southeast Australia 2013, 56 (2):131 Climate Research
Journal:
Climate Research
Issue Date:
26-Mar-2013
DOI:
10.3354/cr01151
Type:
Article
ISSN:
0936-577X; 1616-1572
Additional Links:
http://www.int-res.com/abstracts/cr/v56/n2/p131-145/
Appears in Collections:
Articles; Water Desalination and Reuse Research Center (WDRC); Water Desalination and Reuse Research Center (WDRC); Biological and Environmental Sciences and Engineering (BESE) Division; Biological and Environmental Sciences and Engineering (BESE) Division

Full metadata record

DC FieldValue Language
dc.contributor.authorEvans, J. P.en
dc.contributor.authorMcCabe, Matthewen
dc.date.accessioned2015-05-26T07:29:34Zen
dc.date.available2015-05-26T07:29:34Zen
dc.date.issued2013-03-26en
dc.identifier.citationEffect of model resolution on a regional climate model simulation over southeast Australia 2013, 56 (2):131 Climate Researchen
dc.identifier.issn0936-577Xen
dc.identifier.issn1616-1572en
dc.identifier.doi10.3354/cr01151en
dc.identifier.urihttp://hdl.handle.net/10754/555783en
dc.description.abstractDynamically downscaling climate projections from global climate models (GCMs) for use in impacts and adaptation research has become a common practice in recent years. In this study, the CSIRO Mk3.5 GCM is downscaled using the Weather Research and Forecasting (WRF) regional climate model (RCM) to medium (50 km) and high (10 km) resolution over southeast Australia. The influence of model resolution on the present-day (1985 to 2009) modelled regional climate and projected future (2075 to 2099) changes are examined for both mean climate and extreme precipitation characteristics. Increasing model resolution tended to improve the simulation of present day climate, with larger improvements in areas affected by mountains and coastlines. Examination of circumstances under which increasing the resolution decreased performance revealed an error in the GCM circulation, the effects of which had been masked by the coarse GCM topography. Resolution modifications to projected changes were largest in regions with strong topographic and coastline influences, and can be large enough to change the sign of the climate change projected by the GCM. Known physical mechanisms for these changes included orographic uplift and low-level blocking of air-masses caused by mountains. In terms of precipitation extremes, the GCM projects increases in extremes even when the projected change in the mean was a decrease: but this was not always true for the higher resolution models. Thus, while the higher resolution RCM climate projections often concur with the GCM projections, there are times and places where they differ significantly due to their better representation of physical processes. It should also be noted that the model resolution can modify precipitation characteristics beyond just its mean value.en
dc.relation.urlhttp://www.int-res.com/abstracts/cr/v56/n2/p131-145/en
dc.rightsArchived with thanks to Climate Researchen
dc.subjectRegional climate modelen
dc.subjectModel resolutionen
dc.subjectSoutheast Australiaen
dc.subjectWeather Research and Forecastingen
dc.subjectWRFen
dc.subjectPrecipitationen
dc.titleEffect of model resolution on a regional climate model simulation over southeast Australiaen
dc.typeArticleen
dc.contributor.departmentWater Desalination and Reuse Research Center (WDRC)en
dc.contributor.departmentBiological and Environmental Sciences and Engineering (BESE) Divisionen
dc.identifier.journalClimate Researchen
dc.eprint.versionPublisher's Version/PDFen
dc.contributor.institutionClimate Change Research Centreen
dc.contributor.institutionSchool of Civil and Environmental Engineering, University of New South Wales, Sydney 2052, Australiaen
kaust.authorMcCabe, Matthewen
All Items in KAUST are protected by copyright, with all rights reserved, unless otherwise indicated.