This session focuses on interaction between freshwater continental discharge and coastal sea from their initial mixing and transformation in river estuaries to formation of buoyant river plumes and their spreading in coastal and shelf areas. We will discuss dynamics of the related transport and mixing of freshwater discharge, as well as its influence on physical, biological, and geochemical processes at the continental shelf.
River plumes play an important role in land-ocean interactions. Despite their relatively small surface area and volume as compared to adjacent coastal sea, they significantly influence global fluxes of buoyancy, heat, terrigenous sediments, nutrients, and anthropogenic pollutants, which are discharged to the coastal ocean with continental runoff. River plumes are characterized by strong spatial inhomogeneity and high temporal variability caused by external forcing and mixing processes. Regional features (delta/estuary, enclosed bay/open sea, shoreline, bathymetry, etc.) also significantly influence morphology and behavior of river plumes. As a result, dynamics and variability of river plumes are key factors for understanding mechanisms of spreading, transformation, and redistribution of continental discharge and river-borne constituents in coastal sea and their influence on adjacent continental shelf.
The session will discuss recent advances in understanding mechanisms which govern dynamics and variability of river plumes and estuarine processes based on in situ measurements, satellite observations, and numerical modelling. The session will focus on influence of freshwater discharge and river plumes on stratification and circulation in esuaries and coastal areas, transport and fate of river-borne suspended and dissolved constituents (nutrients, terrigenous sediments, anthropogenic pollutants, litter), impact on coastal nutrient cycle and food webs, sediment deposition and seabed morphology.