Antarctic Ice Sheet freshwater discharge drives substantial Southern
Ocean changes over the 21$^{st}$ century
Abstract
Multidecadal satellite observations indicate that the Antarctic Ice
Sheet (AIS) is losing mass at an accelerating rate, potentially
impacting many aspects of the coupled climate system. While previous
studies have demonstrated the importance of AIS freshwater discharge for
regional and global climate processes using climate model experiments,
many have applied unrealistic freshwater forcing. Here, we explore the
potential Southern Ocean impacts of realistic AIS mass loss over the
21$^{st}$ century in the Community Earth System Model version 2
(CESM2) by applying observation-based historical and ice sheet
model-based future AIS freshwater forcing. The added freshwater reduces
wintertime deep convective area by 72\% while retaining
83\% more sea ice. Congruent with other studies, we find
the increased freshwater discharge extensively impacts local and remote
Southern Ocean surface and subsurface temperature and stratification.
These results demonstrate the necessity of accounting for AIS mass loss
in global climate models for projecting future climate.