Changes in continental and sea-salt atmospheric loadings in central Greenland during the most recent deglaciation: model-based estimates

Date

2017-01-20

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Citation of Original Publication

Alley, R. B., R. C. Finkel, K. Nishiizumi, S. Anandakrishnan, C. A. Shuman, G. Mershon, G. A. Zielinski, and P. A. Mayewski. 1995. “Changes in Continental and Sea-Salt Atmospheric Loadings in Central Greenland during the Most Recent Deglaciation: Model-Based Estimates.” Journal of Glaciology 41 (139). Cambridge University Press: 503–14. doi:10.3189/S0022143000034845.

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This work was written as part of one of the author's official duties as an Employee of the United States Government and is therefore a work of the United States Government. In accordance with 17 U.S.C. 105, no copyright protection is available for such works under U.S. Law.
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Abstract

By fitting a very simple atmospheric impurity model to high-resolution data on ice accumulation and contaminant fluxes in the GISP2 ice core, we have estimated changes in the atmospheric concentrations of soluble major ions, insoluble particulates and ¹⁰Be during the transition from glacial to Holocene conditions. For many species, changes in concentration in the ice typically overestimate atmospheric changes, and changes in flux to the ice typically underestimate atmospheric changes, because times of increased atmospheric contaminant loading are also times of reduced snowfall. The model interpolates between the flux and concentration records by explicitly allowing for wet- and dry-deposition processes. Compared to the warm Preboreal that followed, we estimate that the atmosphere over Greenland sampled by snow accumulated during the Younger Dryas cold event contained on average four–seven times the insoluble particulates and nearly seven times the soluble calcium derived from continental sources, and about three times the sea salt but only slightly more cosmogenic ¹⁰Be.