Climate change in the North Pacific region over the past three centuries

Mount Logan, Yukon viewed from the southwest with
Seward Glacier in the foreground.
Mount Logan from the southwest with Seward Glacier in the foreground. The ice core was extracted on the North side of the mountain (not visible) near the peak on the left. Photo by Gerald Holdsworth.
Climate change in the North Pacific region over the past three centuries
Nature, 420, 6914, 401-403 (28 November 2002); doi:10.1038/nature01229

G. W. K. Moore1, Gerald Holdsworth2, and Keith Alverson3.

1 Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7, Canada
2 Arctic Institute of North America, University of Calgary, Calgary, Alberta T2N 1N4, Canada
3 PAGES International Project Office, Bern CH-3011, Switzerland

The relatively short length of most instrumental climate records restricts the study of climate variability, and it is therefore essential to extend the record into the past with the help of proxy data. Only since the late 1940s have atmospheric data been available that are sufficient in quality and spatial resolution to identify the dominant patterns of climate variability, such as the Pacific North America pattern and the Pacific Decadal Oscillation. Here we present a 301-year snow accumulation record from an ice core at a height of 5,340 m above sea level - from Mount Logan, in northwestern North America. This record shows features that are closely linked with the Pacific North America pattern for the period of instrumental data availability. Our record extends back in time to cover the period from the closing stages of the Little Ice Age to the warmest decade in the past millennium. We find a positive, accelerating trend in snow accumulation after the middle of the nineteenth century. This trend is paralleled by a warming over northwestern North America which has been associated with secular changes in both the Pacific North America pattern and the Pacific Decadal Oscillation.

DATA:
Download the ice core data from the WDC Paleo Archive:

Mt. Logan ice core accumulation and oxygen isotope data, updated to 2000 AD.

Figure 1 Annual snow accumulation at Mount Logan Figure 1.
Annual snow accumulation (m water equivalent) at the Mount Logan site 17002000. Data in the pre-1736 era that is not annually resolved is indicated by the dashed lines.

To read or view the full study, please visit the Nature website.
It was published in Nature, 420, 6914, 401-403 (28 November 2002); doi:10.1038/nature01229

The Mount Logan time series update was supported by the International Arctic Research Center, Fairbanks, the Geological Survey of Canada, the National Institute of Polar Research, Tokyo, and the Natural Sciences and Engineering Research Council of Canada.


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National Oceanic and Atmospheric Administration
28 November 2002