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“There are rivers in the oceans” -- Matthew Maury , Father of Oceanography. The earth is not evenly heated. Net radiative heat gain in the tropics Net radiative heat loss at the poles.
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“There are rivers in the oceans” -- Matthew Maury , Father of Oceanography.
The earth is not evenly heated Net radiative heat gain in the tropics Net radiative heat loss at the poles At the poles: incoming radiation travels through more atmosphere, is spread across more surface area, and is reflected by ice.
Seasons are because of the tilt, NOT getting closer/farther to the sun • If the earth wasn’t tilted, we wouldn’t have seasons
Since the earth is consistantly warmer at the equator, convection causes air at equator to rise, air at poles to sink , thus large planetary winds form.
Remember Coriolis effect on moving things An object moving accross a rotating surface keeps the same direction and speed, but looks seems it curves if you are on the rotating surface. In the fixed (inertial) frame of reference, the black ball moves in a straight line. However, the observer (red dot) standing in the rotating (accelerated) frame of reference sees the object as following a curved path. http://en.wikipedia.org/wiki/Image:Corioliskraftanimation.gif
Convection + coreolis causes winds blowing at these angles across the planet … these are “planetary winds” that blow nearly all the time
Planetary winds are disrupted and modified over land on a daily basis but are nearly constant over the oceans since they are “flat” and uniform
“trade winds” brought the europeans over to the Americas, “Westerlies” brought them back
If the winds are blowing like this… what direction do you predict the ocean surface currents will be moving at the equator?
Western vs Eastern boundary vocabulary to know EAST SIDE OF CONTENTENT EAST SIDE OF OCEAN BASIN WEST SIDE OF OCEAN BASIN WEST SIDE OF CONTENTENT
Which side of all continents have warm currents?What direction to all the warm currents flow?
Which side of all continents have cold currents?What direction to all the cold currents flow?
Western vs eastern currents • WESTERN BOUNDRY: • EASTERN BOUNDRY: HOT and FLOWS TOWARD POLE COLD and FLOWS TOWARD EQUATOR
Currents to know by name • California Current • North Equatorial current • Gulf Stream • North Atlantic dift • Canary Current And in general be able to use these terms • “western boundary current” • “eastern boundary current”
Notice that when put all together the ocean currents cause the oceans to spin in a circle.
What direction do north oceans spin? What direction do south oceans spin?Clockwise or counter clockwise?
These spins are called Gyres there are 5 major gyres North Atlantic Gyre North Pacific Gyre Indian ocean Gyre South pacific Gyre South Atlantic Gyre
Summary: • Unequal heating of the earth, convection and Coriolis work together to set up predictable planetary wind patterns • These constant winds in turn set up constant ocean currents – know the currents by name & location • The ocean currents bring warm water to the west side of all the oceans, cold water to the east side of all the oceans – know which side and what temperature a “western boundry current” would be on in an ocean