Improving the Southern Ocean cloud albedo biases in a general circulation model

Atmospheric Chemistry and Physics (2020)

The present generation of global climate models is characterised by insufficient reflection of short-wave radiation over the Southern Ocean due to a misrepresentation of clouds.

This is a significant concern as it leads to excessive heating of the ocean surface, sea surface temperature biases and subsequent problems with atmospheric dynamics.

In this study, we modify cloud microphysics in a recent version of the Met Office’s Unified Model and show that choosing a more realistic value for the shape parameter of atmospheric ice crystals, in better agreement with theory and observations, benefits the simulation of short-wave radiation.