Upper-ocean dynamics

submesoscale fronts and filaments and eddies, boundary-layer turbulence, internal waves

Upper-ocean dynamics concerns the study of the causes and consequences of flows in the ocean mixed layer and upper pycnocline, including eddies, fronts, filaments, waves, and turbulence. Understanding the dynamics of these flows is critical for understanding and predicting climate because the upper ocean connects the atmosphere (where humans are pumping greenhouse gases) to the deep ocean, where most of the excess heat those gases trap end up.

I’m particularly interested in submesoscale flows in the upper ocean. Those are 0.1-10 km eddies and fronts and filaments associated with large vertical velocities. I’m part of the Sub-Mesoscale Ocean Dynamics Experiment (S-MODE), a NASA Earth Venture Suborbital-3 (EVS-3) mission that aims to test the hypothesis that submesoscale ocean dynamics make important contributions to the vertical exchange of climate and biological tracers in the upper ocean. S-MODE started with a two-week Pilot Campaign in fall 2021. Two month-long intensive operations periods (IOPs) will take place, one in fall 2022 and the other in spring 2023.

As part of S-MODE, we are deploying an array of saildrones in kilometer-scale formation. Saildrones are robotic sailboats rigged with atmospheric and oceanic sensors. Critical observations in S-MODE are velocity profiles from ADCP on saildrones. These will yield unprecedented estimates of submesoscale velocity gradients. I’m leading this saildrone effort, and there are opportunities for students to work with me on S-MODE data.

I was also involved in the Saildrone component of the Atlantic Tradewind Ocean-Atmosphere Mesoscale Interaction Campaign (ATOMIC), led by Chelle Gentemann. As part of ATOMIC, we deployed three saildrones off French Guiana, Suriname and Guyana, where they criss-crossed North Brazil Current Rings. I’m using ATOMIC saildrone data to study submesoscale velocity gradients and fronts in the tropics.

(Upper) A S-MODE saildrone near the Golden Gate Bridge on its way to the Operations Region in the Central California Current for the Pilot Experiment. (Lower left) A saildrone deployed in Barbados for the ATOMIC campaign. (Lower right) Trajectories of three saildrones deployed in the region of the North Brazil Current Rings. Vectors show near-surface velocity measured by one saildrone. Using saildrone data, we are studying km-scale velocity gradients and associated fronts and (vertical) shear layers.