Atmospheric and Oceanic Circulation Patterns

Coriolis effect

Relative to the earth's surface, moving currents of any fluid:
  • Veer to the right in the northern hemisphere
  • Veer to the left in the southern hemisphere

    High and low pressure cells

    Because of the coriolis effect, radial currents always spin

    High pressure cells: cold air spreads out from the center

  • Circulate clockwise (anticyclonic winds) in the northern hemisphere
  • Circulate counterclockwise (cyclonic winds) in the southern hemisphere

    Low pressure cells: warm air rises, pulling cooler air into the center

  • Circulate counterclockwise (cyclonic winds) in the northern hemisphere
  • Circulate clockwise (anticyclonic winds) in the southern hemisphere

    Major ocean surface currents

    Because of the drive of the easterly trade winds and westerly winds, ocean surface water circulates:
  • Clockwise in the northern hemisphere oceans
  • Counterclockwise in the southern hemisphere oceans

    Gulf Stream eddies

    Remember that the water north of the stream is much colder (and richer in nutrients because of upwelling) than the water south of it. The spin direction has to do with initial momentum of the water, not the coriolis effect.
    Peel off north of streamPeel off south of stream
    Spin clockwiseSpin counterclockwise
    Warm eddiesCold eddies
    Stay at surfaceSink deep
    Low in nutrients & lifeHigh in nutrients & life

    Timothy H. Heaton: E-mail, Home page, Phone (605) 677-6122, FAX (605) 677-6121