There was an item on the TV news last night about the Antarctic Ice Cap
melting to lower levels than previously known. It is worth bearing in
mind that the Arctic was a major frontline in the secret war between
Russia and the USA.

A lot of detailed information that was available to the relevant
government bodies was kept out of public domain for that reason. And a
lot of the old records have been released since then.

This is one of the best sites for further information on the subject:
http://polar.ncep.noaa.gov/seaice/icegroup.html

There is a deep sea ocean current that links all the worlds oceans
called the Global Conveyor. It sounds like a ship. Apparently the
system takes centuries to run the circuit. The ice-cap melting may
signifiantly alter the way this system works.

But just how, is not possible to say.

Weatherlawyer wrote:

There is a deep sea ocean current that links all the worlds oceans
called the Global Conveyor. It sounds like a ship. Apparently the
system takes centuries to run the circuit. The ice-cap melting may
signifiantly alter the way this system works.

But just how, is not possible to say.


This article gives a basic idea of how salinity affects the currents.

http://www.scienceagogo.com/news/200...runc_sys.shtml

..

cloud dreamer wrote:

Weatherlawyer wrote:

There is a deep sea ocean current that links all the worlds oceans
called the Global Conveyor. It sounds like a ship. Apparently the
system takes centuries to run the circuit. The ice-cap melting may
signifiantly alter the way this system works.

But just how, is not possible to say.

This article gives a basic idea of how salinity affects the currents.

http://www.scienceagogo.com/news/200...runc_sys.shtml

I wonder what sort of increase is a dramatic one and what they based
this thing on:

"Tropical ocean waters have become dramatically saltier over the past
40 years, while oceans closer to Earth's poles have become fresher,
scientists report in the journal Nature.

These large-scale, relatively rapid oceanic changes suggest that recent
climate changes, including global warming, may be altering the
fundamental planetary system that regulates evaporation and
precipitation and cycles fresh water around the globe.

The study was conducted by Ruth Curry of the Woods Hole Oceanographic
Institution (WHOI); Bob Dickson of the Centre for Environment,
Fisheries, and Aquaculture Science in Lowestoft, U.K.; and Igor
Yashayaev of the Bedford Institute of Oceanography in Dartmouth,
Canada.

Still I suppose if we take it with a grain of salt...

Almost all the rivers in Northern Europe drain into the Baltic and all
of the ones in Russia that don't, drain directly into the Antarctic.
All of Great Britain and Irelands pour into the same neck of the
Arctic/Atlantic. Even the Bay of Biscay is seen as a part of this gyre
that feeds the northern ocean.

Since this region is the intake for the Actic Ocean we aught to expect
it to supply a pale imitation of salt water but the Arctic drains a
large proportion of its output out through Dover Staight as fresh water
-ice.

Of course it could be said that a substantial proportion of the rain
that fills these rivers is provided by the evapouration of the Gulf
Stream, which also feeds the Arctic at the NE of the Atlantic.

However warm salt water tends to sink under cooler fresh watr despite
the temperature difference as the relative densities are the deciding
factor.

So the overall salinity of the Arctic ocean is the same all the way
down. It will be interesting to see how this will change if the NE
coast of North America is devoid of ice in winter.

It surely must.

But I doubt there is any extra input from the sun despite argued
changes in our atmosphere. The greenhouse effect is not what is causing
this problem. It is an agricultural one. Just as it was in the land of
the Pharaohs under Joseph.

Or was there significant industrial pollution in Egypt in those days
and was there enough to have wreaked such havoc as we are experiencing?

Rivers are pouring more salt into the oceans because they are having to
work harder than ever before. And because of the abstraction that is
going on. With modern farming techniques more salts are being fed onto
our land and this is exarcebating the problem.

Fields lack the humous making properties they once had and are drying
out faster than they used to. So aquifers are emptying. Australia and
California, Nevada and Arizona are bone dry.

But Texas and Louisiana are soaking wet; so is a hell of a lot of Asia.

Weatherlawyer wrote:

Or was there significant industrial pollution in Egypt in those days
and was there enough to have wreaked such havoc as we are experiencing?

Or ws there another form of pollution that might have radically changed
the balance of that area's eco system?

Rivers are pouring more salt into the oceans because they are having to
work harder than ever before. And because of the abstraction that is
going on. With modern farming techniques more salts are being fed onto
our land and this is exarcebating the problem.

Here is an abstract about abstraction; some editing:

"CONCLUSIONS

Measurements taken during the study period showed that suspended
sediment concentrations varied considerably with discharge, with
concentration levels exceeding those for average raw sewage (299 mg/l
recorded at Mogden during the study period) being reached during storms
of light precipitation intensity.

The power functional relationship between concentration (mg/l) and
discharge (l/s) for Whitton Brook was found to be Conc. = 0.4183
Q^1.0492 which is more typical of upland catchments on resistant rocks
than lowland gravels-on-clay catchments (Walling and Webb, 1981) and
shows the influence of the built environment on sediment supply.

However, only 15% of the variation in suspended sediment concentration
is explained by the variation in discharge. The relationship was
complicated by:
The effects of [inertial lag] associated with rising and falling
stages.
A progressive decrease in sediment availibility caused by multi-peaked
or closely-spaced storms.
The tendency for the sediment concentration peak to precede the peak
discharge.

The sediment transport patterns presented here are from the complex
hydrological environment of a mostly sewered catchment. The
availability of sediment is dependent on the presence of temporary or
long-term sediment storage systems in the form of:
Road-gullies.
Inadequate pipes and culverts.
Varying rates of delivery from a wide range of land surface types.

This technical report is a brief summary of part of the author's MSc
thesis Suspended Sediment Patterns and Water Quality in an Urban
Watercourse. Kingston University. (1982)."

http://members.aol.com/whittonbrook/

(Well actually it's nothing to do with abstraction.)

















((Or is it?))

Weatherlawyer wrote:

Almost all the rivers in Northern Europe drain into the Baltic and all
of the ones in Russia that don't, drain directly into the Antarctic.

Oops!