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...
| Main Authors: | , |
|---|---|
| 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 |
| Summary: | 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. |
|---|---|
| ISSN: | 1991-959X 1991-9603 |