Sensitivity experiments to mountain representations in spectral models
This paper describes a set of sensitivity experiments to several formulations of orography. Three sets are considered: a "Standard" orography consisting of an envelope orography produced originally for the ECMWF model, a"Navy" orography directly from the US Navy data and a "...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Istituto Nazionale di Geofisica e Vulcanologia (INGV)
2000-06-01
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| Series: | Annals of Geophysics |
| Subjects: | |
| Online Access: | http://www.annalsofgeophysics.eu/index.php/annals/article/view/3658 |
| _version_ | 1811261341700194304 |
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| author | U. Schlese E. Roeckner S. Gualdi M. Biasutti A. Navarra U. Shulzweida |
| author_facet | U. Schlese E. Roeckner S. Gualdi M. Biasutti A. Navarra U. Shulzweida |
| author_sort | U. Schlese |
| collection | DOAJ |
| description | This paper describes a set of sensitivity experiments to several formulations of orography. Three sets are considered: a "Standard" orography consisting of an envelope orography produced originally for the ECMWF model, a"Navy" orography directly from the US Navy data and a "Scripps" orography based on the data set originally compiled several years ago at Scripps. The last two are mean orographies which do not use the envelope enhancement. A new filtering technique for handling the problem of Gibbs oscillations in spectral models has been used to produce the "Navy" and "Scripps" orographies, resulting in smoother fields than the "Standard" orography. The sensitivity experiments show that orography is still an important factor in controlling the model performance even in this class of models that use a semi-lagrangian formulation for water vapour, that in principle should be less sensitive to Gibbs oscillations than the Eulerian formulation. The largest impact can be seen in the stationary waves (asymmetric part of the geopotential at 500 mb) where the differences in total height and spatial pattern generate up to 60 m differences, and in the surface fields where the Gibbs removal procedure is successful in alleviating the appearance of unrealistic oscillations over the ocean. These results indicate that Gibbs oscillations also need to be treated in this class of models. The best overall result is obtained using the "Navy" data set, that achieves a good compromise between amplitude of the stationary waves and smoothness of the surface fields. |
| first_indexed | 2024-04-12T19:02:47Z |
| format | Article |
| id | doaj.art-0dbc46a8363441e481f99fa45789cdf2 |
| institution | Directory Open Access Journal |
| issn | 1593-5213 2037-416X |
| language | English |
| last_indexed | 2024-04-12T19:02:47Z |
| publishDate | 2000-06-01 |
| publisher | Istituto Nazionale di Geofisica e Vulcanologia (INGV) |
| record_format | Article |
| series | Annals of Geophysics |
| spelling | doaj.art-0dbc46a8363441e481f99fa45789cdf22022-12-22T03:20:06ZengIstituto Nazionale di Geofisica e Vulcanologia (INGV)Annals of Geophysics1593-52132037-416X2000-06-0143310.4401/ag-3658Sensitivity experiments to mountain representations in spectral modelsU. SchleseE. RoecknerS. GualdiM. BiasuttiA. NavarraU. ShulzweidaThis paper describes a set of sensitivity experiments to several formulations of orography. Three sets are considered: a "Standard" orography consisting of an envelope orography produced originally for the ECMWF model, a"Navy" orography directly from the US Navy data and a "Scripps" orography based on the data set originally compiled several years ago at Scripps. The last two are mean orographies which do not use the envelope enhancement. A new filtering technique for handling the problem of Gibbs oscillations in spectral models has been used to produce the "Navy" and "Scripps" orographies, resulting in smoother fields than the "Standard" orography. The sensitivity experiments show that orography is still an important factor in controlling the model performance even in this class of models that use a semi-lagrangian formulation for water vapour, that in principle should be less sensitive to Gibbs oscillations than the Eulerian formulation. The largest impact can be seen in the stationary waves (asymmetric part of the geopotential at 500 mb) where the differences in total height and spatial pattern generate up to 60 m differences, and in the surface fields where the Gibbs removal procedure is successful in alleviating the appearance of unrealistic oscillations over the ocean. These results indicate that Gibbs oscillations also need to be treated in this class of models. The best overall result is obtained using the "Navy" data set, that achieves a good compromise between amplitude of the stationary waves and smoothness of the surface fields.http://www.annalsofgeophysics.eu/index.php/annals/article/view/3658General circulationGCM |
| spellingShingle | U. Schlese E. Roeckner S. Gualdi M. Biasutti A. Navarra U. Shulzweida Sensitivity experiments to mountain representations in spectral models Annals of Geophysics General circulation GCM |
| title | Sensitivity experiments to mountain representations in spectral models |
| title_full | Sensitivity experiments to mountain representations in spectral models |
| title_fullStr | Sensitivity experiments to mountain representations in spectral models |
| title_full_unstemmed | Sensitivity experiments to mountain representations in spectral models |
| title_short | Sensitivity experiments to mountain representations in spectral models |
| title_sort | sensitivity experiments to mountain representations in spectral models |
| topic | General circulation GCM |
| url | http://www.annalsofgeophysics.eu/index.php/annals/article/view/3658 |
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