Using Continental Shelf Glider Data to Investigate the Relationship between Oxygen and Organic Material in the Marine Environment
The July 2015 glider data complement understanding of processes in this region by spatially and temporally resolving the structure and variability present on the shelf. A distinct diurnal pattern in dissolved oxygen concentration was observed, with concentrations varying at times greater than 1 mg L-1, at the same depths, from local noon to midnight. Additionally, observations of chromophoric dissolved organic matter (CDOM) and salinity, which are typically inversely related on the shelf, CDOM within a sub-mesoscale eddy was found to be constant throughout the water column and across the entire range of measured salinity. Within this eddy, the largest diurnal variations in oxygen were observed. CDOM/Salinity/oxygen relations indicate the presence of CDOM production across the shelf and at distances too far to have been advected from remote riverine sources.
Our observations demonstrate the extensive variability in biogeochemical processes in the northern Gulf of Mexico and underscore the importance of resolving sub-mesoscale variability beneath the surface as these can impact primary production and remineralization processes.