GEOMAR Helmholtz-Zentrum für Ozeanforschung Kiel
Tel.: 0431 600-0
Fax: 0431 600-2805
11:00 h, Hörsaal, Düsternbrooker Weg 20
Models indicate that much of the dynamical response of the atmosphere to imposed perturbations displays the same spatial patterns as those that dominate temporal fluctuations of the unperturbed climate. Model responses to both increased GHGs and Antarctic ozone depletion show a poleward shift of the midlatitude jet in the southern hemisphere, with an anomaly pattern very much like that of the southern annular mode, the leading pattern of variability in southern hemisphere winds. Similarly, anomalies in the northern hemisphere, on a wide range of time scales, show similar spatial structures.
Such responses are reminiscent of the predictions of the fluctuation-dissipation theorem (FDT), which (amongst other things) relates the perturbed response of a dynamical system to its unperturbed variability. Applications of the FDT to climate problems have met with some success. I will describe some of these successes, as well as some failures and the practical limitations of the FDT.