日本地球惑星科学連合2022年大会

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[J] ポスター発表

セッション記号 M (領域外・複数領域) » M-IS ジョイント

[M-IS20] 南大洋・南極氷床が駆動する全球気候変動

2022年6月2日(木) 11:00 〜 13:00 オンラインポスターZoom会場 (35) (Ch.35)

コンビーナ:関 宰(北海道大学低温科学研究所)、コンビーナ:菅沼 悠介(国立極地研究所)、箕輪 昌紘(北海道大学・低温科学研究所)、座長:関 宰(北海道大学低温科学研究所)、菅沼 悠介(国立極地研究所)

11:00 〜 13:00

[MIS20-P08] Separating of Glacial Isostatic Adjustment (GIA) across Antarctica from GRACE/GRACE-FO observations via Independent Component Analysis (ICA)

*施 天焔1福田 洋一2土井 浩一郎1,2奥野 淳一1,2 (1.総合研究大学院大学極域科学専攻、2.国立極地研究所)

キーワード:南極氷床、GRACE/GRACE-FO、氷河性地殻均衡、独立成分分析

The redistribution of the near-surface solid Earth due to glacial isostatic adjustment (GIA), which is the ongoing response of the solid Earth due to changes in the ice-ocean load following the Last Glacial Maximum, has a direct impact on the inferred Antarctic Ice Sheet (AIS) mass balance from gravimetric data acquired during the Gravity Recovery and Climate Experiment (GRACE) and GRACE Follow-On (GRACE-FO) missions.

However, sparse in-situ observation networks across Antarctica have led to the inability to effectively constrain the GIA effect. Here, we analyze the mass change patterns across Antarctica via independent component analysis (ICA), a statistics-based blind source separation method to extract signals from complex datasets, in an attempt to reduce uncertainties in the glacial isostatic adjustment (GIA) effects and improve understanding of AIS mass balance.

The results reveal that GIA signal could be directly separated from GRACE/GRACE-FO observations without introducing any external model. Although the GIA signal cannot be completely isolated, the correlation coefficients between ICA-separated GIA, and the ICE-5G and ICE-6G models are 0.692 and 0.691, respectively. The study demonstrates the possibility of extracting GIA effects directly from GRACE/GRACE-FO observations.