The impact of climate change on Arctic acidification

The Arctic Ocean experienced severe acidification in the subsurface layer owing to the increased invasion of Pacific Winter Water. However, the recent development and its control mechanisms remain unclear. Here we show that the subsurface acidifying waters (aragnite undersaturation) have further expanded northward, while it has been significantly thinned and shallowed in the western Canada Basin since 2015, in contrast to the thickening and deepening of the acidifying waters during 1994-2015. In the Northern Canada Basin, the more acidic waters in subsurface were also expanded substantially, which is mainly enhanced by the local enhancement of primary production in surface layer due to rapid sea ice loss.