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DY: Dynamik und Statistische Physik

DY 42: Long-Range Correlations and Multifractals

DY 42.5: Hauptvortrag

Donnerstag, 11. März 2004, 12:30–13:00, H2

Long-range correlations in nature: On test-beds for climate models, global warming and natural clustering of hazardous floods — •Armin Bunde — Institut für Theoretische Physik III, Universität Giessen, D-35392 Giessen

A large number of natural records (e.g. temperatures, river flows, heartbeat intervals, internet traffic) exhibit long-term correlations characterized by a power-law decay of the auto-correlation functions C(s)∼ s^−γ. Typical values of γ are γ=0.7 for continental temperature records, γ=0.4 for sea surface temperatures, γ=0.3 for river flows, and γ=0.4 for heartbeat intervals during REM-Sleep. Here we discuss applications and consequences of the long-term correlations. We show that (i) the temperature correlations can be used as an effective test-bed for climate models and discuss (ii) the effect of long-term correlations on the estimation of global warming. Finally we show explicitely that (iii) long-term correlations represent a natural mechanism for clustering of extreme events, by which both the observed clustering of hazardous floods in Europe as well as (at least partially) the increase of floods in the past decades can be explained.