Towards an understanding of the controls on δO2/N2 variability in ice core records

• Main Authors: Harris Stuart, R., Landais, A., Martinerie, P., Dumont, M., Libois, Q., Orsi, A., Grisart, A., Prié, F., Buizert, C., Severinghaus, J.
• Format: Conference Object
• Language: English
• Published: 2023
• Subjects: ice core
• Online Access: https://gfzpublic.gfz-potsdam.de/pubman/item/item_5021860

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.