http://www.agu.org/sci_soc/eosrjohnson.html

"JPG" wrote in message
oups.com...
http://www.agu.org/sci_soc/eosrjohnson.html

Fascinating stuff. I'm already lost at an early stage, though.
How does a hydrologic deficit in the Mediterranean result
in **outflow** through Gibraltar?

Philip

In message , Philip Eden
writes

"JPG" wrote in message
roups.com...
http://www.agu.org/sci_soc/eosrjohnson.html

Fascinating stuff. I'm already lost at an early stage, though.
How does a hydrologic deficit in the Mediterranean result
in **outflow** through Gibraltar?

Philip

If I recall correctly saltier, and hence denser, water flows out of the
Mediterranean at depth, and sinks into the deeper levels of the
Atlantic. To balance this, and the excess of evaporation over inflow and
precipitation, fresher, and hence less dense, water flows into the
Mediterranean nearer the surface.

It is not obviously incorrect that, an increased hydrologic deficit in
the Mediterranean leading to the outflow being even saltier, the
resulting increased density contrast accelerates, and hence increases
the volume of, the outflow.
--
Stewart Robert Hinsley

On 21 Feb, 11:36, "Philip Eden" philipATweatherHYPHENukDOTcom wrote:
"JPG" wrote in message

oups.com...http://www.agu.org/sci_soc/eosrjohnson.html

Fascinating stuff. I'm already lost at an early stage, though.
How does a hydrologic deficit in the Mediterranean result
in **outflow** through Gibraltar?

Philip

The flow at the Strait of Gibraltar is thought to operate under
"hydraulic control" which means that the volume of water exchanged is
determined by the
density contrast between the inflowing surface Atlantic water and the
deeper outflowing
Med water. If there is a hydrological deficit in the Med, the water
there will become saltier and
hence denser. If this density increase is not matched by the inflowing
Atlantic water, the density
contrast between the two increases, leading to more vigorous exchange.

Modelling studies have shown that the characteristics of Med outflow
water are likely to change
over the course of the next century, but it is not generally thought
that this will have a significant
impact on the thermohaline circulation or European climate. The view
of Prof. Johnson was a
minority one even 10 years ago.

21/02/2007 12:08:46
JPG wrote in message
.com

http://www.agu.org/sci_soc/eosrjohnson.html

Perhaps gives added interest to this item -
http://news.bbc.co.uk/1/hi/sci/tech/6341987.stm

Dave, Fair Isle