Have three years of observations explained model biases in Southern Ocean clouds?

Recent climate models have shown biases in surface radiation linked to errors in cloud amount over the Southern Ocean. The NERC funded Southern Ocean Cloud project is trying to explain these biases and has been running for the last three years. It consist of long term measurements of aerosol size and composition at Rothera Station on the Antarctic Peninsula, two airborne campaigns observing cloud properties based out of Rothera and a ship cruise on the Sir David Attenborough, again concentrating on aerosol properties, in the Southern Ocean. The aim of the project is to investigate the sources of aerosols at high southern latitudes and the role they play in clouds. The hope is that this will lead to better representation of these processes within climate models.

Observations made at Rothera Station and on the Sir David Attenborough have identified several distinct types of cloud nuclei and we are working to determine their sources. At the same time these surface based observations, both from Rothera and the ship, are compared with the aircraft observations of cloud properties. These observations are starting to give an insight in to the processes that control clouds over the Southern Ocean and are being used to improve parameterisations of both aerosols and clouds in models.