Posted by Peter Ceresole on May 06, 2009 at 17:38:05 user PeterC.
In Reply to: Re: Daylight saving time posted by andy clayton on May 06, 2009 at 17:06:03:
Take a look at a globe. It spins from West to East. All of that eqatorial water down in the Atlantic flows from east to west as a reaction to the spin.
Strictly speaking, the water doesn't care about (and doesn't feel) the earth's constant spin. What it does feel is coriolis force; at the equator, the water's linear velocity is greater than near the poles (because of the effective change of earth's diameter of rotation), so any movement of the water north or south sheers off to one side to preserve momentum. Heads right going north, and left going south, eastwards in both cases. But as you say, the shape of the Atlantic shore line helps things along.
But I was told that in the South Pacific the main influence is the wind, blowing predominantly westwards, pulling the warm surface water with it away from the coast of Latin America, where it is replaced by cold water upwelling from the depths. It's also full of nutrients, hence the shoals of fish which disappear when the winds fail.
Incidentally, all that cold water, cooling the atmosphere above it, means the water vapour condenses and falls as rain, out to sea. The next high ground inland is the Andes, which is where the air dumps its water, and means that the land between the sea and the Andes is desert- and it jolly well is. Very impressive, rather like the pictures of the Moon, but it means that there's a permanent fresh water problem in Lima, and its surrounding slums. A curious result is that those slums are jolly dry, and as such astonishingly sewage and stink free.
All this is from memory and being there; it may be quite wrong. Is there a meteorologist in the house?