Long-term memory: a natural mechanism for the clustering of extreme events and anomalous residual times in climate records.
We study the statistics of the return intervals between extreme events above a certain threshold in long-term persistent records. We find that the long-term memory leads (i) to a stretched exponential distribution of the return intervals, (ii) to a pronounced clustering of extreme events, and (iii) to an anomalous behavior of the mean residual time to the next event that depends on the history and increases with the elapsed time in a counterintuitive way. We present an analytical scaling approach and demonstrate that all these features can be seen in long climate records. The phenomena should also occur in heartbeat records, Internet traffic, and stock market volatility and have to be taken into account for an efficient risk evaluation.
Bunde
Armin
A
Institut für Theoretische Physik III, Justus-Liebig-Universität Giessen, 35392 Giessen, Germany.
Eichner
Jan F
JF
Kantelhardt
Jan W
JW
Havlin
Shlomo
S
D000465:Algorithms; D002980:Climate; D016000:Cluster Analysis; D003198:Computer Simulation; D004190:Disasters / Q000706:statistics & numerical data*; D015233:Models, Statistical; D010363:Pattern Recognition, Automated / Q000379:methods*; D013223:Statistics as Topic