Presentation on theme: "The East Greenland Current (EGC)"— Presentation transcript:
1 The East Greenland Current (EGC) By Kaycee Coleman
2 The East Greenland Current (EGC) Transports very cold, low salinity water as well as Artic icebergs (>90%) southward along the East Coast of Greenland.There is not much ice formation in the EGC because it is suppressed by the salty water from the Norwegian Atlantic Current. The addition of the saline water to this intense region of cooling destabilizes the water column
3 January 2005 http://www. mercator-ocean It flows from the Fram Strait at 79ºN to Cape Farewell at 60ºN which is one of “the windiest place in the world.”
4 Main freshwater sink for the Arctic It is a source of water for the Labrador Current and the West Greenland Current.It travels through the Greenland Sea, the Norwegian Sea, and the Denmark Strait
6 The East Greenland Current (EGC) The EGC remains geostrophically constrained to the continental margin because of its low-density water and the conservation of potential vorticityEasterly winds can prevent the formation of the eastward extensions to the EGC
7 In the upper parts of the EGC at the Jan Mayen Fracture Zone there are some eastern deflections but this is not well understood, it could be because of the interaction between the bathymetry and the barotropic component of the EGCWater too dense to cross the 620m sill in the Denmark straight goes East, North of Iceland till it reached the 840m sill through the Faeroe-Shetland Channel.
8 Three main water masses of the EGC Polar Water (from the Arctic): m, temperatures between 0ºC and the freezing point. This layer has a strong halocline, with salinity of 30 psu or less at the surface and 40 psu or more at 150 m.Atlantic Intermediate Water: m. Its temperature remains above 0ºC, salinity of 34 psu which increases with depth to between and 35 psu ( with a max at 400 m).Deep Water (which circulate cyclonically): below 800 m, temperature is <0ºC, and with a salinity between and psu.
9 Current speed of the EGC: measurements range from 4 to 20-30 cm s-1 Current speed of the EGC: measurements range from 4 to cm s-1. Transport values for the EGC have vary from 2 Sv to 32 Sv. The computed transport based on the mass and heat budgets obtained an annual mean of 35 Sv. In the North of the EGC the transport in the upper 700 m was calculated to be 3 Sv, half of which was barotropic. Southward, geostrophic transport relative to the bottom is estimated at 4 Sv at 78.4ºN. Causes of error: preferential sampling, different speeds assumed for the Return Atlantic Intermediate Water, and current varies interannually
10 http://www. expeditiongreenland A great deal of ice is transported parallel to the East Greenland coast. In the North the EGC carries about km3 of ice towards the equator annually with an estimated sea ice flux of 1530 km km3 a year. There is a great deal of discrepancies with these measurements and predictions.The ice flux is seasonal with the largest values from October to December and smallest values from January to March. EGC eddies usually have a cross-stream length of about 10 km. These eddies are abundant but do not play a large role in the heat flux (so local baroclinic instability is probably not a major contributor to the mesoscale eddies). Most of the low observed eddy kinetic energy is generated by wind fluctuations.