Accumulation reconstruction and water isotope analysis for 1736–1997 of an ice core from the Ushkovsky volcano, Kamchatka, and their relationships to North Pacific climate records

T Sato,E Edelmann,T Zwinger,R Greve,T Shiraiwa,H Seddik

doi:10.5194/cp-10-393-2014

T Sato, E Edelmann + Show 4 more

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https://doi.org/10.5194/cp-10-393-2014

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Abstract

Abstract. An ice core was retrieved in June 1998 from the Gorshkov crater glacier at the top of the Ushkovsky volcano, in central Kamchatka. This ice core is one of only two recovered from Kamchatka so far, thus filling a gap in the regional instrumental climate network. Hydrogen isotope (δD) analyses and past accumulation reconstructions were conducted for the top 140.7 m of the core, spanning 1736–1997. Two accumulation reconstruction methods were developed and applied with the Salamatin and the Elmer/Ice firn-ice dynamics models, revealing a slightly increasing or nearly stable trend, respectively. Wavelet analysis shows that the ice core records have significant decadal and multi-decadal variabilities at different times. Around 1880 the multi-decadal variability of δD became lost and its average value increased by 6‰. The multi-decadal variability of reconstructed accumulation rates changed at around 1850. Reconstructed accumulation variations agree with ages of moraines in Kamchatka. Ice core signals were significantly correlated with North Pacific sea surface temperature (SST) and surface temperature (2 m temperature). δD correlates with the North Pacific Gyre Oscillation (NPGO) index after the climate regime shift in 1976/1977, but not before that. Therefore, our findings imply that the ice core record contains various information on the local, regional and large-scale climate variability in the North Pacific region. Understanding all detailed mechanisms behind the time-dependent connections between these climate patterns is challenging and requires further efforts towards multi-proxy analysis and climate modelling.

Highlights

Alpine ice core records have two important roles
Ice core signals were significantly correlated with North Pacific sea surface temperature (SST) and surface temperature (2 m temperature). δD correlates with the North Pacific Gyre Oscillation (NPGO) index after the climate regime shift in 1976/1977, but not before that
We presented and analysed water isotope records for the top 140.7 m of the Ushkovsky/K2 ice core

Summary

Introduction

Alpine ice core records have two important roles. One is to provide data for studying local climate characteristics. There are several glacial regions around the North Pacific Ocean that can provide ice cores for paleoclimate reconstructions. The Ushkovsky/K2 ice core is one of two ice cores recovered from Kamchatka (Shiraiwa et al, 2001; Matoba et al, 2011). It is a paleoclimate record for this region that complements regional climate reconstructions from ice cores in Alaska and Yukon (e.g. Holdsworth et al, 1989; Wake et al, 2002; Shiraiwa et al, 2003; Fisher et al, 2004; Yasunari et al, 2007; Fukuda et al, 2011) (Fig. 1a)

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