"Robert Grumbine" wrote in message
...
In article ,
Alastair McDonald k wrote:

Thanks Josh, your efforts are appreciated, but not the way you might
expect.


Murky business, that NADW formation. AABW is much easier, in a
sense, but then again, perhaps only because we don't have as many
observations.

I was at a meeting a couple of years ago when I was told by Prof.
Marakotze, then at Southampton Oceanography Centre, that the
no one yet knew exactly where the NA deep water was formed.

Once you enter the NADW story, you have quite a few players, and
awfully fine balances to be found. Of course that's what makes it
interesting to study.

That was why I raised the subject of cabbeling. I suspect that there are
at least three processes happening in the NA. Salt fingering, cabbeling,
and convection cells.

On this map http://129.13.102.67/wz/pics/Reursst.gif I think I can see
a convection cell (warm cored eddy) forming north north east of Iceland.
It appears and disappears on a daily timescale. That area also seems
to generate a flow of cold fresh water which floats over the North
Atlantic Drift, down from Iceland towards Scotland.

That flow is also obvious in the second map I referenced.
http://www.wetterzentrale.de/pics/brack5.html which also shows a strong
front to the west of Iceland where I suspect cabbeling is happening.


Cabbeling (preferred spelling) is not a potential element for the north
atlantic water mass formation, from my now ancient recollection of the
hydrography.

The Glossary of Physical Oceanography and Related Disciplines appears
to agree with your first point but not your second!
http://ioc.unesco.org/Oceanteacher/r...ean/ocean.html

It has two entries;

- caballing
- See cabbeling.
-
- cabbeling
- In physical oceanography, a phenomenon that occurs when two water
- masses with identical densities but different temperatures and salinities
- mix to form a third water mass with a greater density than either of its
- constituents. This is hypothesized to be a major cause of sinking in
- high northern latitudes. See McDougall (1987b).

I suspect that at the front where temperature is changing rapidly with
distance, that the two masses are altering their densities by change
of temperature until they match, whereupon the water descends (cabbels)
to be replaced by new waters from the two masses in a self perpetuating
process.

There is a paper here about modelling cabbeling by Bob Marsh of
the SOC.
http://citebase.eprints.org/cgi-bin/...ton.ac.uk:8695

As you wrote , Bob,
Once you enter the NADW story, you have quite a few players, and
awfully fine balances to be found. Of course that's what makes it
interesting to study.

Cheers, Alastair.