Melting Ice Dilutes Northern Oceans - BBC

[hatrack]

Freshwater pouring into northern oceans is slowly turning high-latitude waters less salty. Shrinking ice sheets and melting glaciers are partly responsible for the freshening effect, a review in the journal Science has confirmed. If salinity levels continue to drop, dramatic changes to the North Atlantic currents could occur. But more work is needed to be sure that rising global temperatures are to blame, say the authors.

"For the last 50 years, oceanographers have been cruising seas at northern latitudes taking vertical profiles of salinity, and they have observed gradual declines," said lead author Bruce Peterson, of the Marine Biological Laboratory, Woods Hole, US. "The salt water, although still very salty, is getting fresher."

The volume of fresh water is a good match for the amount which rivers, precipitation, sea-ice melt and glacier melt are producing. Run-off from these sources must be creating the dilution effect, the researchers conclude. The measurements are taken from the Nordic seas and Atlantic Sub-polar Basins.

Cold water from the Arctic is usually exchanged for warm water from the tropics in a self-propelling cycle. In the north, the warm water arriving via surface currents sinks and flows back to warmer climes through the deep ocean. Because fresher water is less dense, it does not sink so far as salty water would at the same temperature. If the trend continues, the changes to this current system may be significant. "It is expected that the North Atlantic circulation will slow down," said Professor Peterson.

EDIT

http://news.bbc.co.uk/1/hi/sci/tech/5283570.stm

[Warpy]

1. In the meantime, changes are being observed all over the place

An online buddy on Narragansett Bay has told me there's an invasion of Portuguese man of war jellyfish on south facing beaches, something I never saw on beaches north of the Carolinas.

Another reports that manatees have been sighted in Chesapeake Bay.

Enjoy it while you can, kiddies, the world we know is about to change.

[progressoid]

2. "But more work is needed to be sure..."

Ya, lets put this off for another decade or two.

[tinrobot]

3. There goes the Gulf Stream

Just as predicted.

[glitch]

4. and the great "let's see what happens when we give chimps frontal lobes"

experiment fails spectacularly.

Verdict: reboot.

No biggie when your timeframe is infinity.