This award is for support of a two year study to investigate several gas species in the air occluded in the Vostok ice cores. The glacial-interglacial difference in the carbon isotope ratios of carbon dioxide and methane will be measured, and should provide information on the mechanisms controlling carbon dioxide and methane fluctuations in the atmosphere. The pre-industrial interhemispheric difference in atmospheric carbon dioxide will also be measured to obtain information on the pre-industrial biogenic source variation and on the postulated northern hemispheric oceanic sink. The relative timing of the variations in carbon dioxide and methane will also be studied.
