Local winds and encroaching currents drive summertime subsurface blooms over a narrow shelf

The ability to forecast the biological productivity of coastal ocean relies on quantification physical processes that deliver nutrients euphotic zone. Here we explore these pathways using observations coupled and variability waters offshore east coast Tasmania in summertime. include an array moored autonomous profilers deployed over 18-d period—providing continuous, full-depth measurements turbulent microstructure, temperature, velocity, chlorophyll a (Chl a) fluorescence, complemented by shipboard nutrient measurements. Local upwelling was driven encroaching East Australian Current (EAC) extension onto shelf lesser extent local winds. interaction winds boundary current reflected budget led rapid increase subsurface Chl a. Diffusive vertical fluxes had minimal impact mid-shelf outer-shelf. Upwelling-favorable were too weak drive significant mixing, mixing associated with current-driven Ekman transport deep compared zone depth. observed did not reflect satellite estimates productivity. Since EAC transports warm, low-nutrient surface from subtropics, decreased during same period depth-averaged increased. This seeming paradox illustrated how long duration, full water column sampling can elucidate aid our ongoing effort state ocean.