Shipborne and ground-based observations of clouds in the Southern Ocean

The Southern Ocean is characterised by sparse ground-based and in-situ atmospheric measurements. While satellite measurements provide continuous spatial and temporal coverage, they are generally not capable of observing low-level clouds and the cloud base, which are critical for accurately modelling radiative transfer. Results from general circulation models show significant biases in outgoing shortwave radiation in this region, believed to be related to deficiencies in representation of clouds, aerosols or their interaction. As part of the Cloud and Aerosol project of the New Zealand Deep South Challenge (DSC) we collected and analysed cloud measurements from multiple shipborne and ground-based deployments of several meteorological instruments: ceilometer, lidar, micro rain radar, radio soundings, aerosol sensors, sky cameras and UAV-borne sensors. With this combination of instruments we hope to advance understanding of cloud processes in this region, quantify model error compared to observations and contribute to the modelling effort of the DSC. Currently we have collected observations from a ground-based deployment on Macquarie Island and multiple voyages: Aurora Australis, R/V Tangaroa, HMNZS Wellington and R/V Nathaniel B. Palmer. By incorporating data from these and planned future deployments we intend to produce a Southern Ocean dataset of atmospheric measurements available for general use. This presentation will provide an overview of our progress and results