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| Titel |
Systematic Errors in the ECMWF long range Forecasting System over Africa |
| VerfasserIn |
F. Di Giuseppe, A. M. Tompkins, F. Molteni |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250069038
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| Zusammenfassung |
| In this study the key systematic errors of the ECMWF model over Africa are described by
comparing the new operational seasonal forecasting system (Sys4) with the previous system 3
(Sys3) which used the same model cycle of the ECMWF re-analysis product ERA-Interim.
Focal points of this analysis are (1) documenting the climate errors and forecast skill of the
latest seasonal system, (2) the evolution of model errors across the two systems, (3)
characteristics of the growth of errors throughout the forecast including monthly, and
seasonal time scales.
Results are presented for temperature and humidity fields, cloud related parameters and
the atmospheric circulation. Furthermore, misrepresentation of some key phenomena related
to the monsoon activities in the west Africa and the south-east Africa regions are discussed.
Sys3 seasonal forecast system suffered from a systematic bias whereby monsoon rains
were constantly shifted to the south. This is thought to be related to the cause of a
dry bias in the precipitation amount predicted by short range forecasts initialized
from era-interim analysis over the Sahel.The magnitude of these model errors has
been reduced considerably in the new system. The spatial structure of systematic
model errors, however, remains more or less unchanged for most of the parameters. |
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