[ACC37-P09] アイスコア中の17O-excess の変動傾向
★招待講演
キーワード：アイスコア、北極域、17O-excess
Ice cores obtained from glaciers and ice sheets are important archives for reconstructing changes in the paleoclimate. The most important climate changes, such as the variation in temperature, precipitation, and the hydrological cycle, are reconstructed from stable water isotope ratios (δ18O, δD, and a second-order parameter, the d-excess, defined as d−excess = δD − 8δ18O) measured in ice cores.
With the improvment of water isotope analyzers, the ability to measure δ17O in water with high precision provided another second−order parameter, the 17O−excess, defined as 17O−excess = ln (δ17O+1) − 0.528 ∗ ln(δ18O+1). Previous studies reported that 17O−excess in polar snow is mainly controlled by the relative humidity in the water vapor source region, therefore expected as a new proxy of past climate change. However, at the present, there are few studies of 17O−excess in ice core, and therefore an undrestanding of variation factor of that is incomplete.
In this study, we analyzed δ17O and 17O−excess in an ice core which was drilled in Alaska. We also discussed the variation factors of those associated with environmental change.
With the improvment of water isotope analyzers, the ability to measure δ17O in water with high precision provided another second−order parameter, the 17O−excess, defined as 17O−excess = ln (δ17O+1) − 0.528 ∗ ln(δ18O+1). Previous studies reported that 17O−excess in polar snow is mainly controlled by the relative humidity in the water vapor source region, therefore expected as a new proxy of past climate change. However, at the present, there are few studies of 17O−excess in ice core, and therefore an undrestanding of variation factor of that is incomplete.
In this study, we analyzed δ17O and 17O−excess in an ice core which was drilled in Alaska. We also discussed the variation factors of those associated with environmental change.