JpGU-AGU Joint Meeting 2017

講演情報

[EJ]Eveningポスター発表

セッション記号 A (大気水圏科学) » A-CC 雪氷学・寒冷環境

[A-CC37] [EJ] アイスコアと古環境変動

2017年5月23日(火) 17:15 〜 18:30 ポスター会場 (国際展示場 7ホール)

[ACC37-P09] アイスコア中の17O-excess の変動傾向

★招待講演

*對馬 あかね1Gkinis Vasileios2東 久美子3的場 澄人4本山 秀明3 (1.総合地球環境学研究所、2.コペンハーゲン大学ニールスボア研究所、3.国立極地研究所、4.北海道大学低温科学研究所)

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.