[A-CC26] Ice cores and paleoenvironmental modeling

[ACC26-P02] A quasi-monthly ¹⁰Be record from 2000-2020 CE obtained from the Greenland SE-Dome ice core II

*Riko Yagihashi¹, Kazuho Horiuchi¹, Kohsei Yoshioka², Iizuka Yoshinori³, Sumito Matoba³, Kaoru Kawakami^3,4, Sakiko Ishino⁵, Mahiro Sasage^3,4, Mai Matsumoto^3,4, Takeyasu Yamagata⁶, Hiroyuki Matsuzaki⁶ (1.Graduate School of Science and Technology, Hirosaki University, 2.Faculty of Science and Technology, Hirosaki University, 3.Institute of Low Temperature Science, Hokkaido University, 4.Graduate School of Environmental Science, Hokkaido University, 5.Institute of Nature and Environmental Technology, Kanazawa University, 6.Micro Analysis Laboratory, Tandem accelerator (MALT), The University of Tokyo)

Keywords:Beryllium 10, Cosmogenic nuclides, Greenland, Seasonal variations, Solar activity, Ice core

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.