| Summary: | Processes controlling pore closure are broadly understood yet defining the physical mechanisms driving elemental fractionation remains ambiguous. It has indeed been shown that the pore closure processes lead to a decrease of concentration of small size molecules (e.g. O2, Ar, Ne) in the bubbles. Moreover, ice core δO2/N2 records shows a clear link with local summer solstice insolation and hence makes it a powerful dating tool. However, investigations towards a mechanistic understanding of δO2/N2 and summer solstice insolation suggests local climatic conditions may also be important. We compiled δO2/N2records from several polar ice cores and found a link between δO2/N2 and temperature and/or accumulation rate, in addition to the influence of the summer solstice insolation intensity. Using the Crocus snowpack model, we carry out sensitivity tests to identify the response of near-surface snow properties to changes in insolation, accumulation rate and air temperature.
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