Shortfalls in numerical representations of aerosol-cloud-precipitation-radiation interactions over high latitudes in both hemispheres are associated with biases in simulated radiation budgets caused by uncertainties in representing model feedback processes. Such mechanisms include the sea ice albedo effect and processes driving air mass transformations during meridional transports by warm air intrusions and cold air outbreaks. Improving deficiencies in earth system modeling requires in situ and remote sensing observations to constrain understanding of these complex interactions. Recent observational campaigns over the Arctic and Southern Ocean have been dedicated to improving understanding of microphysical processes occurring in liquid and ice-containing clouds, including determining the roles of primary and secondary marine biogenic aerosol particles and sea-salt emissions on cloud properties. This session welcomes contributions that describe and use data from recent ship/ground/airborne measurements and retrievals of high latitude aerosol, clouds, precipitation, and radiation, and/or use numerical modeling to advance understanding of high latitude processes.