Chapter 10
Atmosphere Ocean Interactions Global Winds and Surface Ocean
CurrentsOcean surface dragged by wind, basins
react to high pressure circulation forming gyres
Cold current, flowing north to south, on west side of continent
Warm current, flowing south to north, on east side of continent
Oceanic front
Stepped Art
Fig. 10-14, p. 273
Atmosphere Ocean Interactions Upwelling
Ekman spiral, Ekman transportWater moving away from the coast causes
upwelling
Fig. 10-16, p. 273
Fig. 10-17, p. 273
Fig. 10-18, p. 274
Atmosphere Ocean Interactions El Nino and the Southern Oscillation
El Nino: irregular warm episode off west coast of South America
Southern Oscillation: rise in pressure over W Pacific, fall in the E Pacific, equatorial countercurrent
ENSOLa Nina (cold waters off the coast of South
america indicating strong upwelling)teleconnections
http://www.pmel.noaa.gov/tao/jsdisplay/
Conditions Fall 2010. For latest update see link below. The Pacific Decadal Oscillation is also presently in its cool phase so colder than average and wetter than average winter is expected this coming winter.
Fall 2010 values are negative indicating a significant La Nina this Fall.
Atmosphere Ocean Interactions Pacific Decadal Oscillation
Reversal in Pacific Ocean temperatures Warm = more Pacific stormsCool = cool, wet NW North America, wetter
over the Great Lakes, salmon fisheries decline
Atmosphere Ocean Interactions North Atlantic Oscillation
Reversal of pressure in North Atlantic Ocean affecting weather in Europe and eastern coast of North America
Positive = strong Westerlies, storms in N Europe, wet and mild in eastern US
Negative = wet southern Europe and Mediterranean, cold and dry in eastern US
Atmosphere Ocean Interaction Arctic Oscillation
Closely related to NAOPressure changes between Arctic and
adjacent southern areas causes changes upper-level winds
Positive = mild winter in US and W EuropeNegative = cold US, cold dry Europe, wet
Mediterranean