Theoretical and Applied Climatology

, Volume 65, Issue 1–2, pp 1–15 | Cite as

Secular Variability of the Coupled Tropospheric and Stratospheric Circulation in the GCM ECHAM 3/LSG

  • F. Feser
  • H.-F. Graf
  • J. Perlwitz

Summary

 Secular or multi-decadal variability is a widely observed phenomenon, apparent in instrumental and paleo climatic records. These long time oscillations are found in many variables of the climate system. The ocean especially experiences low frequency variations. But also atmospheric variables such as temperature, wind velocity and sea level pressure can show secular variability.

The low frequency variability here is examined in the coupled atmosphere-ocean model ECHAM3/LSG T21. A coupled stratospheric and tropospheric mode is detected oscillating with a period of approximately 100 years. The atmospheric pressure system mainly involved in this oscillation is the northern hemispheric winter stratospheric polar vortex. The near surface temperature experiences variations of the same magnitude as the observed temperature trends of the last decades. Multi decadal variability is also shown in the North Atlantic Oscillation Index.

A shift of the length of the oscillation period between longer and shorter time scales indicates that chaotic processes might be responsible for the variability.

Keywords

North Atlantic Oscillation North Atlantic Oscillation Index Polar Vortex Northern Hemispheric Winter Stratospheric Polar Vortex 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer-Verlag/Wien 2000

Authors and Affiliations

  • F. Feser
    • 1
  • H.-F. Graf
    • 2
  • J. Perlwitz
    • 2
  1. 1. Meteorological Institute of the University of Hamburg, GermanyDE
  2. 2. Max-Planck-Institute for Meteorology, Hamburg, GermanyDE

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