Region of freshwater influence

Region of Freshwater Influence (ROFI), a term coined by Prof. John Simpson of the University of Wales, Bangor, and co-authors, in 1993 in Oceanologica Acta for the Rhine river plume. The term refers to regions where rivers debouch into estuaries and coastal shelf seas where the currents patterns are governed by density differences between salt sea water and fresh river water. In other words, a ROFI is the region between the shelf sea regime and the estuary where the local input of freshwater buoyancy from the coastal source is comparable with, or exceeds, the seasonal input of buoyancy as heat which occurs all over the shelf. Americans usually use the term river plume where Europeans use ROFI.