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| Titel |
Reconstruction of recent climate change in Alaska from the Aurora Peak ice core, central Alaska |
| VerfasserIn |
A. Tsushima, S. Matoba, T. Shiraiwa, S. Okamoto, H. Sasaki, D. J. Solie, K. Yoshikawa |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1814-9324
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| Digitales Dokument |
URL |
| Erschienen |
In: Climate of the Past ; 11, no. 2 ; Nr. 11, no. 2 (2015-02-10), S.217-226 |
| Datensatznummer |
250117162
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| Publikation (Nr.) |
 copernicus.org/cp-11-217-2015.pdf |
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| Zusammenfassung |
| A 180.17 m ice core was drilled at Aurora Peak in the central part of the
Alaska Range, Alaska, in 2008 to allow reconstruction of centennial-scale
climate change in the northern North Pacific. The 10 m depth temperature in
the borehole was −2.2 °C, which corresponded to the annual mean air
temperature at the drilling site. In this ice core, there were many
melt–refreeze layers due to high temperature and/or strong insolation during
summer seasons. We analyzed stable hydrogen isotopes (δD) and chemical
species in the ice core. The ice core age was determined by annual counts of
δD and seasonal cycles of Na+, and we used reference horizons of
tritium peaks in 1963 and 1964, major volcanic eruptions of Mount Spurr in
1992 and Mount Katmai in 1912, and a large forest fire in 2004 as age
controls. Here, we show that the chronology of the Aurora Peak ice core from
95.61 m to the top corresponds to the period from 1900 to the summer
season of 2008, with a dating error of ± 3 years. We estimated that the
mean accumulation rate from 1997 to 2007 (except for 2004) was
2.04 m w.eq. yr-1. Our results suggest that temporal variations
in δD and annual accumulation rates are strongly related to shifts in
the Pacific Decadal Oscillation index (PDOI). The remarkable increase in
annual precipitation since the 1970s has likely been the result of enhanced
storm activity associated with shifts in the PDOI during winter in the Gulf
of Alaska. |
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