A spectral nudging method for the ACCESS1.3 atmospheric model

A convolution-based method of spectral nudging of atmospheric fields is developed in the Australian Community Climate and Earth Systems Simulator (ACCESS) version 1.3 which uses the UK Met Office Unified Model version 7.3 as its atmospheric component. The use of...

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Main Authors: P. Uhe, M. Thatcher
Format: Article
Language:English
Published: Copernicus Publications 2015-06-01
Series:Geoscientific Model Development
Online Access:http://www.geosci-model-dev.net/8/1645/2015/gmd-8-1645-2015.pdf
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spelling doaj-b2942bd877a34e5fa65a4002c48449372020-11-24T22:14:45ZengCopernicus PublicationsGeoscientific Model Development1991-959X1991-96032015-06-01861645165810.5194/gmd-8-1645-2015A spectral nudging method for the ACCESS1.3 atmospheric modelP. Uhe0M. Thatcher1CSIRO Oceans and Atmosphere Flagship, 107–121 Station St, Aspendale, VIC 3195, AustraliaCSIRO Oceans and Atmosphere Flagship, 107–121 Station St, Aspendale, VIC 3195, AustraliaA convolution-based method of spectral nudging of atmospheric fields is developed in the Australian Community Climate and Earth Systems Simulator (ACCESS) version 1.3 which uses the UK Met Office Unified Model version 7.3 as its atmospheric component. The use of convolutions allow for flexibility in application to different atmospheric grids. An approximation using one-dimensional convolutions is applied, improving the time taken by the nudging scheme by 10–30 times compared with a version using a two-dimensional convolution, without measurably degrading its performance. Care needs to be taken in the order of the convolutions and the frequency of nudging to obtain the best outcome. The spectral nudging scheme is benchmarked against a Newtonian relaxation method, nudging winds and air temperature towards ERA-Interim reanalyses. We find that the convolution approach can produce results that are competitive with Newtonian relaxation in both the effectiveness and efficiency of the scheme, while giving the added flexibility of choosing which length scales to nudge.http://www.geosci-model-dev.net/8/1645/2015/gmd-8-1645-2015.pdf
collection DOAJ
language English
format Article
sources DOAJ
author P. Uhe
M. Thatcher
spellingShingle P. Uhe
M. Thatcher
A spectral nudging method for the ACCESS1.3 atmospheric model
Geoscientific Model Development
author_facet P. Uhe
M. Thatcher
author_sort P. Uhe
title A spectral nudging method for the ACCESS1.3 atmospheric model
title_short A spectral nudging method for the ACCESS1.3 atmospheric model
title_full A spectral nudging method for the ACCESS1.3 atmospheric model
title_fullStr A spectral nudging method for the ACCESS1.3 atmospheric model
title_full_unstemmed A spectral nudging method for the ACCESS1.3 atmospheric model
title_sort spectral nudging method for the access1.3 atmospheric model
publisher Copernicus Publications
series Geoscientific Model Development
issn 1991-959X
1991-9603
publishDate 2015-06-01
description A convolution-based method of spectral nudging of atmospheric fields is developed in the Australian Community Climate and Earth Systems Simulator (ACCESS) version 1.3 which uses the UK Met Office Unified Model version 7.3 as its atmospheric component. The use of convolutions allow for flexibility in application to different atmospheric grids. An approximation using one-dimensional convolutions is applied, improving the time taken by the nudging scheme by 10–30 times compared with a version using a two-dimensional convolution, without measurably degrading its performance. Care needs to be taken in the order of the convolutions and the frequency of nudging to obtain the best outcome. The spectral nudging scheme is benchmarked against a Newtonian relaxation method, nudging winds and air temperature towards ERA-Interim reanalyses. We find that the convolution approach can produce results that are competitive with Newtonian relaxation in both the effectiveness and efficiency of the scheme, while giving the added flexibility of choosing which length scales to nudge.
url http://www.geosci-model-dev.net/8/1645/2015/gmd-8-1645-2015.pdf
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