Random walk lengths of about 30 years in global climate
John Bye, Klaus Fraedrich, Edilbert Kirk, Silke Schubert, Xiuhua Zhu
GEOPHYSICAL RESEARCH LETTERS | AMER GEOPHYSICAL UNION | Published : 2011
We have applied the relation for the mean of the expected values of the maximum excursion in a bounded random walk to estimate the random walk length from time series of eight independent global mean quantities (temperature maximum, summer lag, temperature minimum and winter lag in land and over the ocean) derived from the NOAA-CIRES twentieth century reanalysis (V2) for 1871-2008 and the ECHAM5 IPCC AR4 twentieth century run for 1860-2100, and also the Millenium 3100 yr control run mil01, which was segmented into records of specified period. The results for NOAA-CIRES, ECHAM5, and mil01 (mean of thirty 100 yr segments) are very similar and indicate a random walk length on land of 24 yr and ..View full abstract
This work was carried out during two invited visits by JATB to the KlimaCampus, University of Hamburg, which are gratefully acknowledged. KF, Max Planck Fellow, and XZ acknowledge support by the Max Planck Society. The 20th Century reanalysis data (NOAA-CIRES 1871-2008) were provided by the NOAA/OAR/ESRL PSD, Boulder, Colorado, from their Web site at http://www.esrl.noaa.gov/psd/. The authors would like to thank our reviewers for their helpful comments and suggestions.