How iceberg geometry affects melting: A multiphase fluids case study
Eric Hester (University of California Los Angeles)
| When |
Sep 19, 2022
from 11:00 to 12:00 |
|---|---|
| Where | Salle des thèses |
| Attendees |
Eric Hester |
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Icebergs transport enormous amounts of fresh water as they melt, altering ocean circulation.We test existing melting parameterisations in a series of laboratory experiments.The parameterisations underestimate melting, and ignore the central importance of iceberg geometry. To understand how geometry affects melting, we turn to numerical simulation, and implement the phase field method in the Dedalus spectral code.The phase field method allows us to evolve the iceberg shape according to temperature and salt fluxes at the boundary. We also discuss how asymptotic analysis can be used to improve the accuracy and efficiency of the phase field method. The simulations reproduce side-dependent melt rates and reveal that
1. at high speeds vortex generation generates localised melt rates up to double the average and
2. at low speeds double diffusive effects drive stronger convection and iceberg melting.
Time permitting, I may also discuss similar methods to simulate boat drag in dead water, and microscale polymer phase separation for cheap single-cell analysis.