 |
| Titel |
Evaluating probabilistic decadal forecasts of Northern Hemisphere extra-tropical cyclone frequencies |
| VerfasserIn |
Tim Kruschke, Henning W. Rust, Christopher Kadow, Gregor C. Leckebusch, Uwe Ulbrich |
| Konferenz |
EGU General Assembly 2014
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250096836
|
| Publikation (Nr.) |
 EGU/EGU2014-12360.pdf |
|
|
|
|
|
| Zusammenfassung |
| Mid-latitudinal cyclones are a key factor for understanding regional anomalies of primary
meteorological parameters, such as temperature, surface wind speed or precipitation. Extreme
cyclones potentially cause tremendous impacts on society and economy, e.g. by enormous
wind-storm induced damages.
Based on an ensemble prediction experiment with 41 annually initialised (1961-2001)
hindcasts, as part of the German MiKlip-initiative for decadal prediction, this study evaluates
a single-model decadal forecast system (MPI-ESM-LR). It analyses, whether the forecast
system can provide skillful probabilistic three-category forecasts (enhanced, normal or
decreased) of extra-tropical winter (ONDJFM) cyclone frequencies over the northern
hemisphere with lead times from one year up to a decade. Thus, it will be analysed whether
the MiKlip-system is of additional value compared to climatological forecasts and
uninitialised climate projections.
It is shown, that these predictions exhibit significant skill, mainly over the North Atlantic and
Pacific for lead times of 2-5 years. Skill for the subset of intense (strongest 25% according to
laplacian of SLP) cyclones is generally higher than for the full set of all detected systems.A
comparison of decadal predictions from different initialisation strategies indicates
systematic differences for some lead times and regions. Additional parameters (e.g. air
temperature, SST, and geopotential height) and indices of large-scale variability modes
(e.g. NAO and PNA) are analysed for a better understanding of the underlying
mechanisms of cyclone frequency modification and thus potential sources of skill. |
|
|
|
|
|
|