Changes in the Arctic and Antarctic climate system are strongly related to processes in the boundary layer and their feedbacks with the free atmosphere. The understanding and quantification of these processes is needed to improve predictions of future changes in the polar regions and their teleconnections with mid-latitude weather and climate. These processes include atmosphere-ocean-ice (AOI) interactions, such as physical and chemical snow processes, exchange of chemical constituents, sources of aerosol, polynya formation processes, sea ice production and bottom water formation, which represent key processes for the atmosphere, ocean and the cryosphere. AOI interactions are also triggered by and have feedbacks with synoptic systems and mesoscale weather phenomena such as cold air outbreaks, katabatic winds and polar lows. Associated processes also include the effect of warm air advection and clouds on the surface energy budget and related boundary layer exchanges. Of increasing interest is the study of extremes such as heat waves and storms, but also extreme meridional transport events that can disturb the physical and chemical state of the high latitudes and may have a large impact on ecosystem changes.

This session is intended to provide an interdisciplinary forum to bring together researchers working in the area of boundary layer processes and high-latitude weather and climate (including snow physics, air/snow chemistry, and oceanography). Cryosphere and Atmospheric Chemistry (the focus of the emerging IGAC activity “CATCH”) processes are highly relevant to this session. We invite contributions e.g. in the following areas:

1. Observations and research on the energy balance, physical and chemical exchange processes, and atmosphere-ocean-ice (AOI) interactions including particle sources.
2. Results from high-elevation sites where similar processes occur over snow and ice.
3. Field programs, laboratory studies and observational studies (including remote sensing).
4. Model studies and reanalyses.
5. Advances in observing technology.
6. External controls on the boundary layer such as clouds, aerosols, radiation.
7. Teleconnections between the polar regions and mid-latitudes resulting in effects related to atmosphere-ice-ocean interactions as well as insights provided by monitoring of water vapor isotopes that shed light on air mass origins.