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10 Be in polar Ice: Data reflect changes in cosmic ray flux or polar meteorology
Author(s) -
Lal D.
Publication year - 1987
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/gl014i008p00785
Subject(s) - polar , atmospheric sciences , cosmic ray , environmental science , latitude , ice core , flux (metallurgy) , stratosphere , attenuation , climatology , polar night , atmosphere (unit) , geology , meteorology , physics , astrophysics , astronomy , geodesy , materials science , optics , metallurgy
We have theoretically estimated the expected changes in the global cosmic ray production of 10 Be in the atmosphere with changes in solar activity, and the consequent variations in its fallout in the polar regions. The global 10 Be 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 10 Be fallout pattern has been derived using the fallout data for 90 Sr 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 10 Be in polar ice in Greenland and in Antarctica, 70°‐78° latitude. It is concluded that the observed variations in 10 Be concentrations in ice cores are primarily due to climatic changes, for both short and long period variations. Thus 10 Be data can be used as a proxy for climate induced meteorological changes in the polar region.