Airborne Remote Sensing of Upper‐Ocean and Surface Properties, Currents and Their Gradients From Meso to Submesoscales

Abstract

In this work we present a unique set of coincident and collocated high‐resolution observations of surface currents and directional properties of surface waves collected from an airborne instrument, the Modular Aerial Sensing System, collected off the coast of Southern California. High‐resolution observations of near surface current profiles and shear are obtained using a new instrument, “DoppVis”, capable of capturing horizontal spatial current variability down to 128 m resolution. This data set provides a unique opportunity to examine how currents at scales ranging from 1 to 100 km modulate bulk (e.g., significant wave height), directional and spectral properties of surface gravity waves. Such observations are a step toward developing better understanding of the underlying physics of submesoscale processes (e.g., frontogenesis and frontal arrest) and the nature of transitions between mesoscale and submesoscale dynamics.

Characterizing the Role of Non‐Linear Interactions in the Transition to Submesoscale Dynamics at a Dense Filament

“…The observations used in this study were collected by the DoppVis instrument (Lenain et al., 2023), a new sensor that is part of the Modular Aerial Sensing System (MASS; Melville et al., 2016), that infers currents from optical observations of the spatio‐temporal evolution, that is, dispersion relationship, of surface waves. This method infers the depth‐resolved Lagrangian current in the upper ocean.…”

“…Confidence intervals of velocity gradient results including kinetic energy flux and fronotgenesis are estimated using a bootstrapped confidence interval and a velocity error of 0.05 m s −1 (Lenain et al., 2023).…”

“…Sea surface temperature observations are collected with a Flir SC6700SLS longwave IR camera (1 m resolution) and Heitronics KT19.85 II infrared thermometer (50 m resolution) (see Melville et al., 2016; Lenain et al., 2023, for details).…”

“…The second field campaign collected observations across two counter‐rotating eddies approximately 45 nautical miles offshore of San Diego on 19 May 2021 from 20:56 to 23:26 UTC (Lenain et al., 2023). This region is referred to as the “eddy region.” Observations using a vessel mounted acoustic Doppler current profiler (ADCP) were collected under the long northwest‐to‐southeast leg of the DoppVis observations from 19 May 2021 10:00 to 20 May 2021 13:00 UTC.…”

“…The second field campaign collected observations across two counter-rotating eddies approximately 45 nautical miles offshore of San Diego on 19 May 2021 from 20:56 to 23:26 UTC (Lenain et al, 2023). This region is referred to as the "eddy region."…”