Gulf stream, recirculation, and other western boundary layer currents

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Gulf stream, recirculation, and other western
boundary layer currents
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• 1. the Gulf Stream
• 2. the coriolis force ant the gyre
• 3.the western boundary current layer

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The Gulf Stream

• powerful, warm, and swift Atlantic ocean current
• originates in the Gulf of Mexico, follows the
  eastern coastlines of the United States, and
  exits through the Strait of Florida.

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The Gulf Stream

• Modifying influence of the climate of the east
  cost of north America.
• extension toward Europe,(North Atlantic drift)
  Western Europe warmer.
• For example, in January, the temperature
  difference between coastal Norway and northern
  parts of continental Canada is approximately 30
  C on average, even if they are the same
  latitude.

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The Gulf Stream

• Finally, the Gulf Stream is one of the strongest
  ocean currents known
• transporting 1.4 petawatts of power.
• moves at a rate of 30 million cubic meters per
  second.
• The volume of the Gulf Stream dwarfs all rivers
  that empty into the Atlantic combined, which
  barely total 1 million cubic meters per second.

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The Coriolis force and the Gyre
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Historically

• Some early writers thought the mighty Mississippi
  River empties in the Gulf of Mexico, and from
  there become the Gulf Stream
• Later, Benjamin Franklin understood that winds
  were the supreme current-producing power in the
  sea.
• In the middle of the 19th century, Commander M.F
  Maury understood, that the currents do not
  invariably follow the winds, but run at right
  angles, or even against the wind

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The Coriolis Force

• Every moving object responds to the "Coriolis
  force."
• In the northern hemisphere the Coriolis force
  always deflects objects to the right.
• In the southern hemisphere the Coriolis force
  deflect objects to the left.

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The Gyre

• Trade winds set up a large-scale gyre motion of
  surface waters in each ocean basin, centered
  roughly on the tropics of Cancer and of
  Capricorn.
• Because of the Coriolis force, surface water is
  deflected toward the interior of the gyres
• if the wind should cease, the water will attempt
  to run downhill from the center of the gyre, and
  be deflected by the Coriolis force
• The gyre keeps turning, while balancing the
  forces of gravity with those of the Coriolis
  force

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Western boundary current layer

• The Gulf Stream is just a portion of the circle
  of the North Atlantic Current
• Why is it so strong compared to its symmetric
  towards Europe costs?.  

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The asymmetry

• Coriolis f2Wsin(theta)
• Define Beta
• 3 attemps to explain limit condition in PDEs
• Sverdrup
• Stommel
• Munk

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Sverdrups theory of the Oceanic Circulation
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Stommel theory of Western boundary currents

• He adds a botom stress proportional to velocity
• Coriolis depending or not on latitude explains
  Gulf Stream

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Munks solution

• He adds lateral friction

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