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Millennial climate variability: GCM‐simulation and Greenland ice cores
Author(s) -
Blender Richard,
Fraedrich Klaus,
Hunt Barrie
Publication year - 2006
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2005gl024919
Subject(s) - climatology , geology , sea surface temperature , arctic , climate model , ice core , sea ice , arctic ice pack , paleoclimatology , climate change , environmental science , oceanography
The low frequency variability of the near surface temperature in a climate simulation is compared with Greenland ice core δ 18 O time series during the holocene. The simulation is performed with the coupled CSIRO atmosphere‐ocean model under present‐day conditions. The variability, analyzed by the detrended fluctuation analysis, reveals power‐law scaling of the power‐spectrum for frequency f , S ( f ) ∼ f −β , and long term memory (LTM) given by β > 0. The near surface temperature shows intense LTM in the North Atlantic south of Greenland, weak LTM in parts of the Antarctic ocean and the tropical Atlantic, and no LTM in the Pacific ocean. The power‐law exponent β ≈ 0.5 near Greenland agrees with ice core temperature proxies up to time scales of 1000 years. The LTM of the surface temperature is explained by the high low frequency variability of the zonally averaged stream‐function in the Atlantic with maxima in the Arctic ocean.