A Novel Integration of an Ultraviolet Nitrate Sensor On Board a Towed Vehicle for Mapping Open-Ocean Submesoscale Nitrate Variability

Initial results from a deployment of the SUV-6 ultraviolet spectrophotometer, integrated with the SeaSoar towed vehicle, are presented. The innovative, combined system measures nitrate concentration at high spatial resolution (4 m vertically, 5 km horizontally), high sensitivity (0.2 μM), and concomitantly with temperature, salinity, and dissolved oxygen. The authors demonstrate that this approach constitutes a powerful new tool for quantifying the role of mesoscale and submesoscale vertical nutrient fluxes to the euphotic zone, using measurements from a high-resolution survey of an eddy dipole in the Iceland Basin during the summer of 2007.