Decadal Cyclone Variability in the North Atlantic
Luksch U, Raible CC, Blender R, Fraedrich K
Met. Zeitschrift
submitted Aug 2004


Abstract: The non-stationarity of the midlatitude ocean-atmosphere coupling motivates the definition of two decadal regimes with distinct implications for the North Atlantic cyclone variability. Phases with low (high) decadal variability of the North Atlantic Oscillation, which are connected with an annular (sectoral) spatial scale of the geopotential height teleconnection pattern, are identified as a hemispheric (regional) regime. In the hemispheric regime the North Atlantic cyclones and the regions of enhanced precipitation shift southward for a positive El Ni\~no/Southern Oscillation (ENSO) index, a warm event, while over northern Europe the cyclone activity and the rainfall are reduced. During the regional regime this impact of ENSO on the Atlantic storm track is extremely small and a clear interpretation over Europe is inhibited.

KeyWords Plus: ATMOSPHERIC CIRCULATION TRENDS, NORTH ATLANTIC OSCILLATION, ALEUTIAN LOW, STATIONARY WAVE ACTIVITY, EDDY ACTIVITY, OCEAN, SEA SURFACE TEMPERATURE

Addresses:
Raible C.C., Climate and Environmental Physics, Physics Institute, University of Bern, Sidlerstr. 5, CH-3012 Bern, Switzerland.
Blender R, Luksch U, Fraedrich K, Univ Hamburg, Inst Meteorol, Bundesstr 60, Hamburg, Germany

Reprints (after having been accepted):
Raible CC, Climate and Environmental Physics, Physics Institute, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland, raible@climate.unibe.ch