The East African Institute for Fundamental Research (EAIFR)  wishes to inform those who may be interested of a GEO@EAIFR webinar. This seminar will take place on July 22, 2025 and will be broadcast live on ZOOM. It will also be recorded and later posted on the ICTP-EAIFR YouTube channel, where one can find the previous recorded GEO@EAIFR webinars. Below all the details:

Speaker: Dr. Grae Worster, Professor of Fluid Dynamics, Department of Applied Mathematics and Theoretical Physics, University of Cambridge

Title: The fluid dynamics inside sea ice

When: July 22, 2025 at 4:00 pm (Kigali time).

Register in advance for this meeting by clicking here.

All are very welcome.

Abstract: Sea ice, the ice that forms when the polar oceans freeze, is not solid but is made up of platelets of ice separated by concentrated brine (salty sea water) that form a porous medium through which the brine can flow.  Because the ice platelets are pure water, the brine between them is much saltier than the sea water below, and the associated density difference drives convection that causes the brine to drain from the sea ice into the ocean.  I will describe mathematical, experimental and field studies of such convection from sea ice.  The conclusion of these studies is a relatively simple, one-dimensional, mathematical description that can be used in climate models to predict the brine fluxes and the associated buoyancy fluxes from sea ice, which affect the worlds ocean circulations significantly.

Biography: Grae Worster completed his PhD at the University of Cambridge, UK in 1983, has been an Instructor in Applied Mathematics at MIT and an Assistant Professor in Applied Mathematics and Chemical Engineering at Northwestern University.  He is currently Professor of Fluid Dynamics in the Department of Applied Mathematics and Theoretical Physics, University of Cambridge, where he has been since 1993.  His research focuses on buoyancy-driven flows and phase change, particularly in situations where these two phenomena interact.  In the context of climate change, he has combined mathematical modelling and laboratory experiments to understand and quantify the mechanisms affecting brine drainage from sea ice, the flow and stability of marine ice sheets and fundamentals of frost heave.  Since its founding in 2003, Grae has been a frequent lecturer at AIMS South Africa (African Institute for Mathematical Sciences) and wrote the book “Understanding Fluid Flow” based on his lectures there.