This work package focuses on: Interaction of the Southern Ocean with the atmosphere.

What controls the exchange of heat and carbon across the air-sea-ice interface, and how well are these exchanges constrained by observations and reproduced by models?

The focus of Work Package 1 is on determining the magnitude and temporal changes of the heat and carbon exchanges between the atmosphere and the sea surface, in order to address the question “What controls these air-sea exchanges and how well are they constrained by observations and reproduced by models?”.  Current state-of-the-art climate models are very sensitive to the magnitude and distribution of air-sea-ice exchange in the Southern Ocean, but the scarcity of atmospheric and oceanic observations in the region means that the reanalyses used to force ocean-only models are poorly constrained, and there are limited data for climate model validation.

WP1 aims to address these issues by:

1. Making new, targeted observations of the air-sea-ice fluxes of momentum, sensible heat, latent heat and CO₂, along with flux-related parameters such as surface water pCO₂ and mean meteorological variables.
2. Assessing the uncertainty in existing Southern Ocean observations of fluxes and flux-related parameters, including an assessment of satellite fields of SST and surface winds.
3. Assessing the sensitivity of ocean-only models to realistic uncertainty in forcing fields and in flux parameterisations using both an adjoint modelling approach and by perturbation experiments.
4. Assessing the representation of air-sea-ice fluxes in a range of coupled climate and Earth System models to investigate their flux-related biases.