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.
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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
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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.
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