[M-IS05] 南大洋・南極氷床が駆動する全球気候変動

[MIS05-P16] A linkage between Antarctic sea-ice extent and ice-shelf basal melting in summer: A circumpolar model study

*草原 和弥¹ (1.海洋研究開発機構)

キーワード：棚氷海洋相互作用、海氷

Recent observations indicate that two cryospheric components, namely the Antarctic sea ice and ice shelf over the Southern Ocean, have been changing over the decades. Here we analyze results from an ocean–sea ice–ice shelf model to examine the relationship between the Antarctic sea-ice extent and ice-shelf basal melting. The model reproduces seasonal and interannual variability in the Antarctic sea-ice extent and indicates that summertime ice-shelf basal melting is closely anti-correlated with the sea-ice extent anomaly. For example, the unprecedented minimum of the Antarctic sea-ice extent in the 2016 spring was accompanied by a substantial increase in the Antarctic ice-shelf melting in the model. Detailed analysis of Antarctic coastal water masses flowing into the ice-shelf cavities reveals a possible physical link in the strong anti-correlation. This study suggests that the Antarctic sea-ice extent in summer can be a proxy for Antarctic coastal water masses and subsequent ice-shelf melting.