Radiocarbon in polar ice: The mechanism by which radiocarbon is preserved in firn grains

This work is devoted to the problem of localizing the 14 C cosmogenic radionuclide in a firn layer covering glaciers. The data on 14 C in ice samples from the GISP2 ice core drilled on a Greenland ice dome (Summit) are analyzed. It has been indicated that experimental values of the 14 C concentration are systematically smaller than theoretically calculated values, which indicates that firn grains partially lose 14 C. Diffusion of cosmogenic 14 C in firn grains and hydration of 14 CO 2 in a disordered ice layer, which is formed on a firn grain surface and at the boundary between ice monocrystals, are considered. It has been indicated that these processes are among the main ones responsible for the level of radiocarbon concentration in firn and ice samples.