Ocean current hemisphere due to imposed wind stresses. In these wind-driven currents, the Ekman spiral effect results in the currents flowing at an angle to the driving winds. In addition, the areas of surface ocean currents move somewhat with the seasons; this is most notable in equatorial currents. Deep ocean basins generally have a non-symmetric surface current, in that the eastern equatorward-flowing branch is broad and diffuse whereas the western poleward flowing branch is very narrow. These western boundary currents (of which the Gulf Stream is an example) are a consequence of the rotation of the Earth. Deep ocean currents are driven
North Atlantic Tracks tracks were known as 'Track Sierra Mike' (SM) and 'Track Sierra Oscar' (SO) for westbound flights and 'Track Sierra November' (SN) for eastbounds. An additional route, 'Track Sierra Papa' (SP), was used for seasonal British Airways flights from London Heathrow to/from Barbados. North Atlantic Tracks North Atlantic Tracks, officially titled the North Atlantic Organised Track System (NAT-OTS), is a structured set of transatlantic flight routes that stretch from the northeast of North America to western Europe across the Atlantic Ocean. They ensure aircraft are separated over the ocean, where there is little radar coverage. These heavily traveled routes are used