Abstract
Recent mass loss from ice sheets and ice shelves is now persistent and
prolonged enough that it impacts downstream oceanographic conditions. To
demonstrate this, we use an ensemble of coupled GISS-E2.1-G simulations
forced with historical estimates of anomalous freshwater, in addition to
other climate forcings, from 1990 through 2019. In this ensemble there
are detectable differences in zonal-mean sea surface temperatures (SST)
and sea ice in the Southern Ocean, and in regional sea level around
Antarctica and in the western North Atlantic. These impacts mostly
improve the model’s representation of historical changes, including
reversing the forced trends in Southern Ocean surface temperature and
Antarctic sea ice. The changes in SST may have implications for
estimates of the SST pattern effect on climate sensitivity and for cloud
feedbacks. We conclude that the changes are sufficiently large that
these drivers should be included in all-forcing historical simulations
in coupled model intercomparisons.