The Gulf Stream separates from the US coast near Cape Hatteras (35°N, 75°W) and then travels eastwards across the North Atlantic, becoming the North Atlantic current at about 55°W. In the region between 75°W and 55°W it is subject to meanders and is frequently accompanied by eddies. The northern edge of the current is marked by a sharp fall in temperature. This is also the case at much greater depths, so that the warm current is pressed up against a wall of cold water, called the 'north wall'. Monthly charts of the path of the north wall of the Gulf Stream have been available from surface, aircraft and satellite observations since 1966 and these have been used in several studies of the path's variability.
