Premium
Ice‐core data evidence for a prominent near 20 year time‐scale of the Atlantic Multidecadal Oscillation
Author(s) -
Chylek Petr,
Folland Chris K.,
Dijkstra Henk A.,
Lesins Glen,
Dubey Manvendra K.
Publication year - 2011
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 - 10.1029/2011gl047501
Subject(s) - atlantic multidecadal oscillation , climatology , scale (ratio) , geology , oscillation (cell signaling) , ice core , el niño southern oscillation , north atlantic oscillation , oceanography , environmental science , geography , cartography , biology , genetics
Using five ice core data sets combined into a single time series, we provide for the first time strong observational evidence for two distinct time scales of Arctic temperature fluctuation that are interpreted as variability associated with the Atlantic Multidecadal Oscillation (AMO). The dominant and the only statistically significant multidecadal signal has a time scale of about 20 years. The longer multidecadal variability of 45–85 years is not well defined and none of the time scales in this band is statistically significant. We compare these observed temperature fluctuations with results of coupled climate model simulations (HadCM3 and GFDL CM2.1). Both the 20–25 year and a variable longer AMO time scale are prominent in the models' long control runs. This periodicity supports our conjecture that the observed ice core fluctuations are a signature of the AMO. The robustness of this short time scale period in both observations and model simulations has implications for understanding the dominant AMO mechanisms in climate.