Processes of Vertical Exchange in Shelf Seas (PROVESS)

Papers in this and a companion issue report on an interdisciplinary study of the vertical fluxes of properties throughout the water column from the sea surface to the seabed. The project was centred on measuring and modelling for two contrasting sites in the North Sea of turbulence properties and their effects on particles, zooplankton and nutrient cycling, particularly the relative importance of cycling in the water column, the seabed fluff layer and the sediments. Turbulence activity was weaker at the northern site, which stratified in summer, and where measurements were obtained during the start of the autumnal breakdown of stratification. The southern site, where measurements were taken during and after the spring bloom, was much more dynamic both in terms of turbulence and of particles. The site was close to the Dutch coast and was well mixed throughout the year, except for the intermittent influence of the Rhine plume. The study contributes towards the long-term goal of developing robust water column plankton models applicable in the full range of turbulence environments encountered in continental shelf seas.