Submesoscale eddy contribution to ocean vertical heat flux diagnosed
from airborne observations
Abstract
Submesoscale eddies (those smaller than 50~km) are
ubiquitous throughout the ocean, as revealed by satellite infrared
images. Diagnosing their impact on ocean energetics from observations
remains a challenge. This study analyzes a turbulent field of
submesoscale eddies using airborne observations of surface currents and
sea surface temperature, with high spatial resolution, collected during
the S-MODE experiment in October 2022. Assuming surface current
divergence and temperature are homogeneous down to 30 m depth, we show
that more than 80% of the upward vertical heat fluxes, reaching
~227 W~m^{-2}, is explained by the
smallest resolved eddies, with a size smaller than 15 km. This result
emphasizes the contribution of small-scale eddies, poorly represented in
numerical models, to the ocean heat budget and, therefore, to the
climate system