A research group led by Ikumi Oyabu of the National Institute of Polar Research (NIPR) has analyzed multiple ice cores (Figure 1) drilled at and around the Dome Fuji station in the Antarctic interior (Figure 2) to precisely estimate snow cover variations over the past 5000 years. Because the Antarctic interior is so large, even small changes in snow cover impact ice sheet mass changes. However, measuring these changes has been difficult due to the extremely low annual snowfall. The authors found a long-term decrease in snow cover over the last 5000 years, followed by a significant increase after the Industrial Revolution (~150 years ago) (Figure 3). The long-term decrease may be caused by long-term surface cooling over the Southern Ocean and East Antarctica and sea ice expansion in the moisture source area, while the subsequent increase may be attributed to an increase in greenhouse gas concentrations and stratospheric ozone depletion. These results are important for understanding the relationship between the Antarctic ice sheet mass balance and climate change, as well as for validating climate and ice sheet models for future predictions.

Figure 1. Ice core drilling at the NDF site by the 59th Japanese Antarctic Research Expedition (see Figure 2(B)) (top) and the NDF2018 ice core with volcanic ash layer (bottom). The age of the layer is estimated to be 1613 BCE.

Figure 2. (A) Overall view of the Antarctic ice sheet. (B, C) Expanded view of the Dome Fuji region targeted in this study.

Figure 3. Mean accumulation rate around Dome Fuji over the last 5000 years.

<Published Paper>

 

Ikumi Oyabu, Kenji Kawamura, Shuji Fujita, Ryo Inoue, Hideaki Motoyama, Kotaro Fukui, Motohiro Hirabayashi, Yu Hoshina, Naoyuki Kurita, Fumio Nakazawa, Hiroshi Ohno, Konosuke Sugiura, Toshitaka Suzuki, Shun Tsutaki, Ayako Abe-Ouchi, Masashi Niwano, Frédéric Parrenin, Fuyuki Saito, and Masakazu Yoshimori (2023) Temporal variations of surface mass balance over the last 5000 years around Dome Fuji, Dronning Maud Land, East Antarctica. Climate of the Past, Volume 19, issue 2, 293-321, DOI： 10.5194/cp-2022-68.

URL:

https://cp.copernicus.org/articles/19/293/2023/