Tree-ring reconstructions of temperature and sea-level pressure variability associated with the warm-season Arctic Oscillation since AD 1650

Reconstructions of warm season AO SAT (top) and SLP index for AD 1650-1975.
Reconstructions of warm season AO SAT (top) and SLP index for AD 1650-1975. Click to enlarge.
Tree-ring reconstructions of temperature and sea-level pressure variability associated with the warm-season Arctic Oscillation since AD 1650
Geophysical Research Letters
Vol. 30, No. 11, 1549 (June 2003).


Rosanne D. D'Arrigo, Edward R. Cook, Gordon C. Jacoby
Lamont-Doherty Earth Observatory, Palisades, New York, USA.

Michael E. Mann
University of Virginia, Charlottesville, Virginia, USA.


ABSTRACT:
Arctic Oscillation (AO) changes are inferred from a treering reconstruction of a warm-season temperature index. The reconstruction covers AD1650-1975 and is based largely on chronologies from circumpolar-Arctic and circum-North Atlantic areas. It accounts for 48% of the variance in the instrumental AO record from 1900 to 1975, verifies using independent data, and exhibits its largest variance at low frequencies. Positive levels during 20th century periods equal or exceed values back to AD 1650. Trends (including lower values during 'Little Ice Age' periods) resemble those of Arctic temperature reconstructions, reflecting some data overlap, but also the strong link between the AO and northern temperatures. A reconstruction of an AO summer sea level pressure index shows similar trends. Comparison of these reconstructions with proxies of the North Atlantic Oscillation (NAO) and other indices can help clarify relationships between the AO and NAO, at least during the boreal warm season.

DATA:
Download the data from this study:
Warm Season Arctic Oscillation Reconstructions, Surface Air Temperature and Sea Level Pressure

To read or view the full study, please visit the AGU website.
It was published in Geophysical Research Letters Vol. 30, No. 11, 1549 (June 2003)

This work was supported by US National Oceanic and Atmospheric Administration CIFAR Grant UAF-02-0033 and the US National Science Foundation Earth System History Grant ATM02-11583.


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National Oceanic and Atmospheric Administration
14 July 2003