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| Titel |
Assessing predictability over the North Atlantic / Europe arising from stratosphere - troposphere coupling in a seasonal prediction system |
| VerfasserIn |
Daniela Domeisen, Amy Butler, Kristina Fröhlich, Wolfgang Müller, Johanna Baehr |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250087593
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| Publikation (Nr.) |
 EGU/EGU2014-1650.pdf |
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| Zusammenfassung |
| Predictability on seasonal timescales over the North Atlantic / Europe region is assessed
using a seasonal prediction model based on an initialized version of the Max Planck Institute
Earth System Model. The two dominant predictors are El Niño and sudden stratospheric
warming (SSW) events. In the prediction system, the evolution of El Niño events is reliably
predicted, and stratospheric variability is reproduced well in hindcast runs with a realistic
frequency of SSW events.
While multiple studies have shown a potential for improved predictability for
either predictor, we here aim to quantify the predictive skill arising for both types of
events, which are shown to not be independent. An El Niño teleconnection exists
in the model involving a deepened Aleutian Low in the Northern Pacific, which
influences the Northern winter stratosphere. The stratospheric anomaly then propagates
downward into the troposphere on seasonal timescales while being amplified by
SSW events. Predictability of 500hPa geopotential height over Northern Europe
is then shown to be increased for El Niño events for lead times of 3-5 months. |
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