[S-GD01] 測地学・GGOS

[SGD01-04] GRACE/GRACE-FO Observed Mass Change Patterns of Antarctica Extracted by ICA Method

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

キーワード：GRACE、GRACE-FO、独立成分分析、南極、GIA

Antarctica is one of the most rapidly mass changing areas with poor field observation data. Considering the dominant uncertainty in Glacial Isostatic Adjustment (GIA) effects for the Antarctic Ice Sheet (AIS) mass balance, we analyze mass change patterns of Antarctica qualitatively using a statistics-based blind source separation method named Independent Component Analysis (ICA). We extract the 6 leading independent components using gravimetric data derived from the Gravity Recovery and Climate Experiment (GRACE) mission and GRACE Follow-On (GRACE-FO) mission. The results show that the whole continental mass changes can be effectively separated into several spatial patterns that could be dominated by different physical processes. Although the hidden independent physical processes cannot be completely separated, some significant signals such as glacial melting components, snow accumulation components, periodic climatic components, and GIA effects could be determined without introducing any external information. We also found that the time period of the employed datasets has a direct impact on ICA results. This suggested that some impacts of extreme events, such as rapid increases of snowfall in the late 2000s might cause dramatic changes spatially and temporally. In general, ICA provides a special view for a better understanding of AIS mass changes and specific regional researches.