Dynamical downscaling of Era40 in Norway
Abstract
A novel approach for downscaling of the Era40 data set has been taken and results from comparison with observations in Norway will be presented. The approach make use of a nudging technique in a stretched global model with the grid focus at (67N, 5W). The effective resolution is three times the one of the Era40, equivalent to about 30km grid spacing in the area of focus. Longer waves are nudged towards Era40 while the short waves are set free to evolve. The comparison to observations incorporate numerous station data points of i) precipitation (#357), ii) temperature (#98) and iii) wind (#10), and the new data set shows large improvements over Era40. The results from daily precipitation show considerably reduction in bias (from 50% to 11%), and a two-fold reduction (-59% to 29%) at 99.9%tile level. The daily temperature bias was reduced by about a degree in most areas, and the RMSE was reduced significantly (from 7.5 to 5.0 except winter). The wind comparison indicated a slight improvement in bias, and significant improvement in RMSE.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2008
- Bibcode:
- 2008AGUFM.A13A0217S
- Keywords:
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- 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE