Real oceanographers have been studying the Carribean Sea and the Gulf of Mexico (GoM) for many years to explain the antics of the Loop Current (LC). I came along with the notion that the sea level difference between the GoM entrance at Cabo San Antonio (CSA) and the Florida Current outlet at Settlement Point (SP) is driving the LC behavior. Unable to upgrade this notion into a respectable hypothesis, I examined the sea level at Key West (KW), which is the junction between the LC and the Florida Straits. I have come to view the Florida Straits and Florida Current as the drain channel for the GoM. I view the GoM as a big tub, whose sea level has a profound effect on New Orleans.
Sea level difference between points along the flow path represents power dissipation due to turbulent friction. I have plots starting in Nov.1985 for the overall path (CSA-SP), the GoM segment (CSA-KW), and the drain segment (KW-SP). If you multiply these sea level differences by the water density times the acceleration of gravity times the volume transport rate, you get the power dissipated in turbulent friction. Over the two-month period examined in my last post, (CSA-SP) increased 6 cm while (CSA-KW) decreased 16.5 cm and (KW-SP) increased 22.5 cm. There is some vagueness about volume transport rate because this varies, and I tend to use an average value. There is additional vagueness because the Florida Current is augmented by current that bypasses the Gulf via the Old Bahama Channel along the northeast coast of Cuba. Nevertheless, the power dissipation in the drain path increased by about 60 GW, and only a quarter of this was supplied by external drive (CSA-SP). The other three quarters was due to a transfer of resistance from GoM to the drain path.
What could have caused this 42 GW of resistance to move from the GoM into the drain channel? The real oceanographers have been examining eddies and vortices coming through the Yucatan Channel from the Caribbean Sea as possible triggers for the separation of rings from the LC. Perhaps these disturbances move downstream into the drain channel and cause the blockage. Or maybe they form in the Florida Straits or at the left turn required to go around the tip of Florida. This is pretty heavy stuff for me to lift, so my next step will just be to examine all the upstream-downstream dissipation shifts since Nov.1985, and see if there is a pattern.
That was my thought,too.
Posted by: Belstaff Leather Jacket | March 06, 2012 at 02:12 PM