日本地球惑星科学連合2018年大会

講演情報

[EJ] ポスター発表

セッション記号 A (大気水圏科学) » A-CG 大気水圏科学複合領域・一般

[A-CG38] 北極域の科学

2018年5月24日(木) 13:45 〜 15:15 ポスター会場 (幕張メッセ国際展示場 7ホール)

コンビーナ:津滝 俊(東京大学)、漢那 直也(北海道大学 北極域研究センター)、鄭 峻介(北海道大学 北極域研究センター、共同)、中村 哲(北海道大学大学院地球環境科学研究院)

[ACG38-P23] グリーンランド北西、SIGMA-Dサイトで掘削されたアイスコア中の17O-excessの変動から見る北極域の水循環変動

*對馬 あかね1東 久美子2的場 澄人3永塚 尚子2青木 輝夫4藤田 耕史5 (1.総合地球環境学研究所、2.国立極地研究所、3.北海道大学低温科学研究所、4.岡山大学、5.名古屋大学大学院環境学研究科)

キーワード:アイスコア、17O-excess、グリーンランド

The stable water isotope ratios (δ18O, δD and d-excess which is clculated from δD and δ18O) in ice cores are important proxy of paleo climate change. Recently, δ17O and 17O−excess which is clculated from δ18O and δ17O have attracted attention as a promising new proxy of hydro-climate variation. In this study, we measured δ17O, δ18O and δD in an ice core, which was obtained from the northwest Greenland using Wavelength-Scanned Cavity Ring-Down Spectroscopy (model L2140-i; Picarro) with high precision at the National Institute of Polar Research. And we also calculated d-excess and 17O-excess form those. For last 80 years, the correlation of 17O-excess and d-excess is definitely changed with period of 10 to 20 years. The correlation of those shifted in 1967, that is, we showed sea-level pressure in periods 1(1949-1967) and 2(1968-1980) (NCEP Reanalysis data provided by the NOAA/OAR/ESRL PSD, Boulder, Colorado, USA, from their Web site at http://www.esrl.noaa.gov/psd/cgi-bin/data/composites/printpage.pl). During the periods 2, the high-pressure area extended across the whole Greenland, therefore, water vapor was hard to reach to SIDMA-D site. We think that the moisture influx route to SIGMA-D site and its amount changed due to the climate field change, resulting the changes of those correlations.