Optical microstructure in the thermohaline staircase east of Barbados

Images of optical microstructure from the ocean thermocline east of Barbados are presented, including examples of turbulence, a shear billow and a diffusively unstable interface. While much of the water column was favorable to salt fingering, particularly the high gradient interfaces in the staircase, the few centimeters wide vertical banding reported in other fingering-favorable parts of the ocean were not observed. Instead, almost horizontal banding appeared wherever conditions were conducive to fingering. The role that vertical shear plays in modifying salt fingers may have to be reconsidered.