How may gyres exist in the world ocean?

N. Pacific Gyre N. Atlantic Gyre Temperatures represented by: Red: 25 to 28C (77 to 82F) Yellow: 20 to 25C (68 to 77F) Indian Ocean Gyre S. Atlantic Gyre S. Pacific Gyre Green: 15 to 20C (59 to 68F) Blue: 0 to 15C (32 to 59F) An illustration of sea-surface temperature showing the general direction and pattern of surface current flow. Sea-surface temperatures were measured by a radiometer aboard NOAA-7 in July 1984. The purple color around Antarctica and west of Greenland indicates water below 0C, the freezing point of freshwater. Note the distortion of the temperature patterns we might expect from the effects of solar heating alonethe patterns twist clockwise in the Northern Hemisphere, counterclockwise in the Southern Greenland N. Pacific kurosho North Equatorial Current Equatorial counter South Equatorial C+ Ecuatrime En. Couderc Equatore Buinea N. Equato Equatorial Counter Brash Curreny AUS AL Antarctic Circumpolar Current Antarctic Circumpolas (West Wind Drirent - Warm-water current Cold-water current b A chart showing the names and usual direction of the world ocean's major surface currents. The powerful western boundary currents flow along the western boundaries of ocean basins in both hemispheres. Figure 9.8 Two ways of viewing the major surface currents of the world ocean