10Be in polar Ice: Data reflect changes in cosmic ray flux or polar meteorology

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Abstract
We have theoretically estimated the expected changes in the global cosmic ray production of 10Be in the atmosphere with changes in solar activity, and the consequent variations in its fallout in the polar regions. The global 10Be production rate is found to be about 20% higher during periods of very low solar activity, compared to the average solar modulation level observed during the past 3 solar cycles. The stratospheric 10Be fallout pattern has been derived using the fallout data for 90Sr as an analog. This fallout shows an amplitude attenuation by a factor of about three at 70°; the higher the latitude, the higher the attenuation. The results have been compared with the long time series available for 10Be in polar ice in Greenland and in Antarctica, 70°‐78° latitude. It is concluded that the observed variations in 10Be concentrations in ice cores are primarily due to climatic changes, for both short and long period variations. Thus 10Be data can be used as a proxy for climate induced meteorological changes in the polar region.