Thermohaline energy transfers and global warming:

http://www.aip.org/history/climate/oceans.htm


Another great unknown was the interaction between currents like the
Gulf Stream and the giant eddies that the currents spun off as they
meandered. Evidence of these broad, sluggishly rotating columns of
water had turned up during a survey voyage across the North Atlantic
in 1960. This was confirmed by an international campaign carried out
by six ships and two aircraft in the early 1970s — another example
of how studying ocean phenomena needed international cooperation.
The survey discovered eddies bigger than Belgium that plowed through
the seas for months. What oceanographers had supposed were static
differences in the oceans between their sparse measuring-points, had
often actually been changes over time, not over space.
The oceanographers had been vaguely aware that when meteorologists
built atmospheric models, they included the energy carried by wind
eddies as an important factor (physical oceanography, as one
practitioner remarked, was "to some extent a mirror of
meteorology"). Yet it was astounding to see what prodigious
quantities of heat, salt, and kinetic energy the ocean eddies
carried. Indeed nearly all the energy in the ocean system was in
these middle-sized movements, not in the ocean currents at all.
(28*)

He has set free the two seas meeting together. There is a barrier
between them. They do not transgress. (Quran, 55:19-20)

He is the one who has set free the two kinds of water, one sweet
and palatable, and the other salty and bitter. And He has made
between them a barrier and a forbidding partition. (Quran, 25:53

Or (the unbelievers’ state) is like the darkness in a deep sea. It
is covered by waves, above which are waves, above which are clouds.
Darknesses, one above another. If a man stretches out his hand, he
cannot see it.... (Quran, 24:40)

Water is not like air, and computers that could handle meteorological computations were far too slow to work through comparable models for this swirling ocean "weather." As one ocean modeler complained in 1974, "Extensive research efforts have not yet yielded much more than a greater appreciation of the difficulty of these questions."(29) To get a handle on the problem, oceanographers had to understand the oceans from top to bottom. But they had little data on the depths — the occasional expeditions, retrieving bottles of water here and there from kilometers down, were like a few blind men trying to map a vast prairie. Oceanographers liked to remark that we had better maps of the face of the Moon than of the deep sea. After all, there was little economic incentive, nor much military interest either, in studying the colossal slow movements of water, salts, and heat through the abyss.