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JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 111, D15107, doi:10.1029/2005JD006410, 2006

Modeling production and climate-related impacts on ¹⁰Be concentration in ice cores

Christy V. Field

Department of Earth and Environmental Sciences and NASA Goddard Institute for Space Studies, Columbia University, New York, New York, USA

Gavin A. Schmidt

NASA Goddard Institute for Space Studies and Center for Climate Systems Research, Columbia University, New York, New York, USA

Dorothy Koch

NASA Goddard Institute for Space Studies and Center for Climate Systems Research, Columbia University, New York, New York, USA

Colette Salyk

Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, USA

Abstract

The connection between the production of the cosmogenic isotope ¹⁰Be and changes in heliomagnetic activity makes ice core ¹⁰Be an attractive proxy for studying changes in solar output. However, interpreting ¹⁰Be ice core records on centennial timescales is complicated by potential climate-related deposition changes that could obscure the ¹⁰Be production signal. By using the Goddard Institute for Space Studies ModelE general circulation model to selectively vary climate and production functions, we model ¹⁰Be flux at key ice-coring sites. We vary geomagnetic field strength and the solar activity modulation parameter (), CO₂, sea surface temperatures, and volcanic aerosols to assess impacts on ¹⁰Be. Specifically, we find significant latitudinal differences in the response of ¹⁰Be fluxes to changes in the production function. In the climate experiments the ¹⁰Be deposition changes simulated over ice sheets in both hemispheres are comparable to those seen in the production experiments. This altered deposition combined with changes of snow accumulation results in significant climate-related ¹⁰Be concentration variation in both Greenland and Antarctica. Over the Holocene our results suggest that the ¹⁰Be response to climate change should not be neglected when inferring production changes.

Received 24 June 2005; accepted 10 April 2006; published 11 August 2006.

Keywords: solar; climate change; ice cores.

Index Terms: 7537 Solar Physics, Astrophysics, and Astronomy: Solar and stellar variability (1650); 3305 Atmospheric Processes: Climate change and variability (1616, 1635, 3309, 4215, 4513); 0724 Cryosphere: Ice cores (4932).

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Citation: Field, C. V., G. A. Schmidt, D. Koch, and C. Salyk (2006), Modeling production and climate-related impacts on ¹⁰Be concentration in ice cores, J. Geophys. Res., 111, D15107, doi:10.1029/2005JD006410.

Copyright 2006 by the American Geophysical Union.