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OCN 5401. Chapter 7 Major Ocean Currents Instructor: Dr. George A. Maul gmaul@fit.edu / X 7453. Ocean Circulation has two components. Thermohaline (deep). Wind driven (surface). Global Winds.
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OCN 5401 Chapter 7 Major Ocean Currents Instructor: Dr. George A. Maul gmaul@fit.edu / X 7453
Ocean Circulation has two components Thermohaline (deep) Wind driven (surface)
THE WIND-DRIVEN CIRCULATION: Surface ocean currents form a distinctive pattern, curving to the right (clockwise) in the northern hemisphere and to the left (counterclockwise) in the southern hemisphere. Benjamin Franklin’s Map Computer Model Map
Arctic Ocean Currents RV Fram Fridtjof Nansen
Western Boundary Currents SSH variability
Eastern Boundary Currents Benguela Current coastal deserts California Current KonTiki
Indian Ocean Currents SSH sea surface temperature Modeled SSH, March
Southern Ocean Currents dissolved silica
Equatorial Currents Equatorially trapped currents ζ+f= constant
El Niño SSTs La Niña SSTs
ENSO – El Niño Southern Oscillation Enso String Quartet
Transect along western Atlantic Ocean showing water masses and general circulation processes.
Stommel, 1958 North Atlantic Deep Water (NADW) when warm salty surface water from south cools and sinks to form a deep western boundary current (DWBC).
Deep Western Boundary Current You’re kidding, right? It flows to the south?
The major thermohaline circulation cells that make up the global conveyer belt are driven by exchange of heat and moisture between the atmosphere and the ocean.
The Conveyor Belt - but is it correct? “For the past several decades, oceanographers have embraced the dominant paradigm that the ocean’s meridional overturning circulation operates like a conveyor belt, transporting cold waters equatorward at depth and warm waters poleward at the surface. Within this paradigm, the conveyor, driven by changes in deepwater production at high latitudes, moves deep waters and their attendant properties continuously along western boundary currents and returns surface waters unimpeded to deepwater formation sites. A number of studies conducted over the past few years have challenged this paradigm by revealing the vital role of the ocean’s eddy and wind fields in establishing the structure and variability of the ocean’s overturning. Here, we review those studies and discuss how they have collectively changed our view of the simple conveyor-belt model.” M.S. Lozier, Science, 2010.
OCN 5401 Chapter 7 Questions?