Fig. 1: Wintertime submesoscale frontogenesis event.
a Snapshot of sea surface height anomaly in the Ocean Surface Mixing, Ocean Submesoscale Interaction Study (OSMOSIS) observational region on 7 February 2013, with surface geostrophic current velocity shown as black vectors. Sea surface height anomaly and surface geostrophic velocity data are obtained from the delayed-time gridded 0.25° × 0.25° Archiving, Validation and Interpretation of Satellite Oceanographic Data (AVISO) product. b Visible and Infrared Imaging Radiometer Suite (VIIRS) sea surface temperature image on 7 February 2013 at 14:07 UTC, with the OSMOSIS moorings indicated as white dots and a 2 km distance scale shown in white for reference. Data missing due to cloud cover are shaded in gray. The location of the VIIRS image is marked with a pink box in (a). Time series of (c) potential density ρ, (d) kinetic energy (KE), (e) normalized horizontal convergence − δ/f, (f) normalized frontogenetic rate Tb/f, (g) vertical velocity w, and (h) energy transfer rate \({\Pi }_{\omega }^{2d}\) estimated at the central mooring from 7–9 February, 2013. The black lines indicate the glider-derived mixed layer depth, and the vertical dashed lines denote 14:07 UTC on 7 February 2013 in (c–h).
