Sea ice-ocean exchange of Arctic microplastics: Linking small scales to the large-scale system

Sea ice growth and melt with idealized entrainment and release of MP particulates. Samples of lab-grown ice will be used to simulate the progression from initial, rapid ice growth and MP entrainment (left), slower growth of thicker ice and reduced entrainment (center), and warming ice, brine drainage, and MP release (right).

The problem of microplastics (MPs) in the Arctic marine system is of recent interest, spurred by field observations that show surprisingly high MP concentrations in sea ice, ocean, sediment, and snow-on-ice. These have been supplemented by a very few modeling and laboratory studies. In this proposal, we aim to advance the field via the development of new laboratory techniques to understand sea ice MP, exchange with the ocean during uptake and release, and MP optical effects on the sea ice mass balance. We will also develop parameterizations for use in open-source, community 1D and 3D sea ice, ocean, and climate models, and run these models to assess large-scale Arctic MP time/space distributions and the impact of MPs on climate in both hindcast and future simulations. Three questions guide our interdisciplinary research: (1) How do MPs interact with sea ice? (2) How can we parameterize MP sea ice-ocean interactions?  (3) Where are MPs in the Arctic Seas?