[A-CC26] アイスコアと古環境モデリング

[ACC26-P02] グリーンランド南東ドーム第二期アイスコアから得られた2000年から2020年の約一ヶ月分解能¹⁰Be記録

*八木橋 理子¹、堀内 一穂¹、吉岡 恒星²、飯塚 芳徳³、的場 澄人³、川上 薫^3,4、石野 咲子⁵、捧 茉優^3,4、松本 真依^3,4、山形 武靖⁶、松崎 浩之⁶ (1.弘前大学大学院理工学研究科、2.弘前大学理工学部、3.北海道大学低温科学研究所、4.北海道大学大学院環境科学院、5.金沢大学環日本海域環境研究センター、6.東京大学総合研究博物館)

キーワード：ベリリウム１０、宇宙線生成核種、グリーンランド、季節変動、太陽活動、アイスコア

Here, we present a quasi-monthly ¹⁰Be record from 2000 to 2020 CE obtained from an ice core drilled in 2021 from the southeastern dome of the Greenland ice sheet (hereafter as SE-Dome II). The SE-Dome II site is located at latitude 67°11'30" N, longitude 36°28'13" W, and elevation 3161 m. An accurate age model was constructed based mainly on annual layer counting using the seasonality of H₂O₂ concentration in SE-Dome II (Kawakami et al., in preparation). Sample preparation was performed according to a standard procedure for ice core ¹⁰Be analysis (e.g. Horiuchi et al., 2007) at the Paleoenvironmental and Cosmogenic Nuclide Laboratory of Hirosaki University. ¹⁰Be was analyzed by accelerator mass spectrometry at the Micro Analysis Laboratory Tandem Accelerator of the University of Tokyo. The ¹⁰Be concentrations ranged from 0.27×10⁴ to 1.74×10⁴ atoms/g. Seasonal variations characterized by an increase from late spring to early summer were evident in the ¹⁰Be profile throughout the period. On the other hand, the annually averaged ¹⁰Be concentration correlates well with the ¹⁰Be production rate in the atmosphere estimated from neutron monitor observations and a production model (Poluianov et al., 2016), but with a lag of a few years. In this poster, we will further discuss the nature and causes of the ¹⁰Be variations from 2000 to 2020 CE.