SWOT Science team

I am a member of the SWOT (Surface Water Ocean Topography) science team. This satellite is scheduled to be launched in 2020 and will measure the fluctuations of the sea surface height at an unprecedented resolution of 500 m horizontally. Unfortunately, the temporal resolution will be of 10 to 21 days, which is much too slow to distinguish the fast internal waves from geostrophic flows such as mesoscale (~100 km in mid-latitudes) or even sub-mesoscale (~10 km in mid-latitudes) vortices, which are much slower to evolve.

SWOT art

My self-appointed role in this endeavor is to come up with ways to (i) diagnose the effects of wind-generated internal waves on those geostrophic flows and (ii) to disentangle tide-generated internal waves from geostrophic flows.

Problem (i) is tricky because wind-generated internal waves flow horizontally and do not displace the sea surface. Even when extremely powerful, they will be invisible to SWOT, and yet, they might impact mean and geostrophic flows it will measure (see "Critical reflection of internal waves in submesoscale flows" and "Particle dispersion by stochastic waves" below for examples). Our understanding of these types of wave-mean flow interactions is still in its early stages, and I intend to pursue idealised studies of the fundamental physics at play. I work on this problem in collaboration with Leif Thomas (Stanford University).

In a way, Problem (ii) is the opposite from Problem (i): tide-generated internal waves do displace the sea surface vertically, and "pollute" (or are polluted by, depending on one's point of view) the measurement of geostrophic flows. The silver bullet to separate the two types of flows is using time analysis, but SWOT data will not have the temporal resolution to do so. In collaboration with Aurélien Ponte (Ifremer Brest), Brian Arbic (University of Michigan) and Francis Poulin (University of Waterloo), I plan on devising filtering methods using idealised studies and (synthetic) data.