High resolution aerial sea surface temperature observations of small-scale frontal features in the open ocean

Abstract

Small-scale (e.g. submesoscale and boundary layer scale) ocean features, like fronts and eddies, play a critical role in the transport and mixing of tracers. Despite recent advances, resolving such small-scale features in satellite imagery remains challenging. Accurately representing sub-grid-scale features in ocean models also remains an active area of research that should be guided by observations. Here, we present high resolution (~1 m) aerial observations of sea surface temperature that were acquired in December 2019 offshore of the island of Fogo (Cape Verde). The SST observations were obtained by a longwave infrared camera system that was operated from a Stemme powered glider. Direct georectification of open-ocean SST imagery was performed using the position and orientation data obtained from a global navigation satellite system receiver and an inertial navigation system. Georectified SST images were transferred in real-time to the R/V Meteor  to enable in situ sampling across a rapidly evolving front. The SST observations show strong convergence at the front and elevated Rossby Numbers (~O10-100), which are indicative of non-linear flows.