Intense atmospheric rivers can weaken ice shelf stability at the Antarctic Peninsula

The disintegration of the ice shelves along the Antarctic Peninsula have spurred much discussion on the various processes leading to their eventual dramatic collapse, but without a consensus on an atmospheric forcing that could connect these processes. Here, using an atmospheric river detection algorithm along with a regional climate model and satellite observations, we show that the most intense atmospheric rivers induce extremes in temperature, surface melt, sea-ice disintegration, or large swells that destabilize the ice shelves with 40% probability. This was observed during the collapses of the Larsen A and B ice shelves during the summers of 1995 and 2002 respectively. Overall, 60% of calving events from 2000-2020 were triggered by atmospheric rivers. The loss of the buttressing effect from these ice shelves leads to further continental ice loss and subsequent sea-level rise. Under future warming projections, the Larsen C ice shelf will be at-risk from the same processes.

Automated summary

This study uses an atmospheric river detection algorithm, regional climate model, and satellite observations to investigate the processes leading to the dramatic collapse of ice shelves in the Antarctic Peninsula. The research finds that intense atmospheric rivers have a 40% probability of inducing extremes in temperature, surface melt, sea-ice disintegration, or large swells that destabilize the ice shelves. This phenomenon was observed during the collapses of the Larsen A and B ice shelves. The study also reveals that 60% of calving events from 2000-2020 were triggered by atmospheric rivers, highlighting their significant role in ice shelf stability.