CCA2: Surface processes

The warming-induced retreat of sea ice and snow cover are obvious changes observed in the Arctic environment. The interface between the atmosphere and the surface – characterised by snow cover, sea ice, open ocean, or land mass – is decisive for climate feedback processes, as the different surface fluxes are driving the changes in the Arctic climate system.

• Bring together projects that are working on atmospheric processes over particular surfaces,
• Combining the observed and modelled changes of surface properties,
• Quantify their impact on the Arctic climate

• What is the impact of the changing albedo on the cloud radiative effect in the different Arctic sub-regions?
• How do the changing Arctic surface properties affect the emission of marine aerosol precursors as a source of INP, and thus the aerosol-cloud interaction in the Arctic (link to CCA3)?
• What is the impact of changing surface conditions (e.g., leads, roughness, sea surface temperature) in the Arctic on near-surface air temperatures (link to CCA1), turbulent and radiative energy fluxes, and on air mass transformation (link to CCA4)?

• Collect data on albedo and other surface properties for various Arctic sub-regions investigated within diverse (AC)³ projects,
• Scaling results of process-based studies to broader Arctic requires the consideration of differences and heterogeneity in the underlying surface. Therefore, CCA2 will consolidate projects whose research is related to exchange processes between land, ocean, ice and atmosphere and how they can be improved in models,
• Includes effects of Arctic surface heterogeneity and improvement of albedo parametrisations, surface coupling of clouds and their radiative effect over different terrain, as well as the emission of marine aerosol precursors and its effect on the aerosol-cloud interactions.