Ocean Currents and Heat Transport

[marchesarosa]

tall bloke says

The southern ocean absorbs more heat than the northern continents. The S.H. excess has to cross the equator to even out the planetary energy balance as it works towards maximum entropy. But this isn’t a smooth or steady process. The belching of SH energy in to the NH takes place on various timescales: seasonal, decadal, right down to glacial/interglacial frequencies.

Verity Jones says

This is a recent animation of all the surface currents around the world during the period from June 2005 through Decmeber 2007. (Now all they need to do is colour them by temperature), and it does indeed show where the heat does cross the equator most effectively.

diggingintheclay.wordpress.com/2012/03/31/life-in-the-clouds/

[marchesarosa]

homepage.mac.com/williseschenbach/atlantic_ocean_thermohaline_circulation.jpg


The oceans are constantly being fed very, very cold water from the poles. The water there is cooled. When it is cooled it sinks, and over time spreads across the bottom of the ocean. Here’s a cross-section:



“NADW” is North Atlantic Deep Water. “AABW” is Antarctic Bottom Water. Both sink because they are cold, with the AABW being the colder of the two. As a result, it ends up below the NADW.

And because the oceans are thermally stratified, warmest at the top and coldest at the bottom, the sun never gets to warm the bottom waters …

w.


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Thanks to Willis Eschenbach.