Laboratoire Matière et Systèmes Complexes

There will be a live diffusion with Zoom.

Monday July 4th, 11h30

Contact Michael Berhanu to attend the visio-seminar.

The frozen Arctic Ocean : a tank experiment at the scale of the Earth

Michel Tsamados

Centre for Polar Observation and Modelling

University College London

Abstract : By how much is the sea ice albedo feedback mechanism projected to contribute to global warming ? How thick is the sea ice and can we measure this from space ? How far in advance can we predict the fate of the sea ice using sophisticated dynamical models or statistic tools ? Is the ice going to melt from above under accelerated Arctic warming or from below due to its Atlantification ? Is the sea ice dynamics a good analogous of accelerated tectonic plates ? Are we waking up the sleeping Arctic Ocean ? How far at the ocean waves penetrating into the ice pack and are they going to play a key role in fragmenting the evermore fragile thin Arctic ice layer ? How does the Arctic Ocean bathymetry affect the evolution of the surface of the Arctic ocean ? Ultimately could the melt of the Arctic sea ice impact the global thermohaline circulation and our climate system ?

In this seminar I will use satellite and airborne remote sensing data as well as state of the art climate models to illustrate some of the questions above. I will show that under each of these questions often lie equations that can be found in other field of geophysics or physics with analogous system also seen in the lab. I will provide examples from the research I have undertaken over the last 12 years at the Centre for Polar Observation and Modelling at UCL. Examples will be given of novel parameterization I introduced in sea ice models such a new anisotropic rheology, a form drag friction parameterization, melt ponds and other thermodynamic processes. I will emphasise that detailed monitoring of this hugely complex system over a wide range of scales (from mm and seconds to decades and 1000s of km_ reveals a plethora of phenomena often of outstanding beauty in their own right but also with important implications for the fate of the climate of our Planet.

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