Modelling Climate, Solar and Geomagnetic Related Variations in the Deposition of Ice Core Beryllium-10 Isotopes

Columbia University, New York NY

Investigators

Abstract

This award will allow the use a state-of-the-art atmospheric general circulation model to examine the impacts of climate and production rate changes on the deposition of Beryllium-10 isotopes (10Be) in ice cores. These results will in turn be used to constrain the different causes of variability in 10Be fluxes and thus improve estimates of possible solar magnetic field related production changes. Over decadal to centennial timescales, hypothesized variations in production rate, due to solar variability, are small, and the potential for climate impacts large. Therefore, before 10Be records can be unambiguously used to constrain solar variation, these impacts must be quantitatively addressed. This study will incorporate a stratosphere with a full aerosol tracer module and will focus on three separate questions: What is the impact of climate change on 10Be concentrations and flux? How are changes in 10Be production (solar and geomagnetic) recorded? How do solar changes in irradiance and production impact 10Be deposition? The model will be subjected to a large number of relevant climate forcings (both radiative and sea surface forcing). The proposed work should provide a deeper understanding of the information contained within the 10Be ice core records, and thus an improved estimate of solar variations through time. Better understanding of such forcings of past climate will help estimate the degree of variability in the Earth System and ultimately be an aid to environmental and economic policy makers.