Abstract

This talk focuses on examples of coupled particle-fluid interactions on our planet that can produce dramatic emergent behaviour of societal and climate importance. The most extreme wildfires are increasing in intensity and frequency and create their own weather. Here, progress towards understanding the self-organisation of wildfire smoke from the surface to the stratosphere will be presented. Topics include aerosol-filled vortices, self-reinforcing instabilities associated with wildfire smoke, and physics of wildfire-driven plumes. The last part of the talk is on fast-flowing ice on Earth that typically occurs over beds with thin layers of deformable sediment, such as ice streams and surging glaciers. Mechanisms by which ice can ‘surge’ forward quasi-episodically with order-of-magnitude accelerations in ice velocity are debated. Using a physically consistent model for the ice-sediment interface, a stability theory for surge behaviour will be presented. The talk will conclude with an outlook on the dynamics of wildfire and ice.