Thursday, April 22, 2010

Salinity: another way to spell climate change

Sea salt: it's not just a condiment anymore.




















Piling confirmation on top of confirmation (Frank Wentz showed this was happening with MSU/AMSU data), new analyses of ocean salinity using ARGO buoys show that the Earth's water cycle is getting more intense due to climate change --- oh, I'm sorry, skeptics and deniers, what I meant to say was, Earth's water cycle is getting more intense due to GLOBAL WARMING.

What's that mean? Well, salinity can be used as a tracer of the water cycle; if a region of the world's oceans is getting saltier, that means there's more evaporation taking place there. If a region of the world's oceans is getting fresher, that means it's raining more there.

Two article about this:

Ocean Salinities Show an Intensified Water Cycle

and

Oceans' Saltiness Reaching Extremes


From the latter:


"What they found is that the subtropical, evaporation-dominated waters of the Indian, Atlantic and Pacific oceans are getting saltier while the tropical and higher latitude waters are getting fresher -- these later areas being where there is more rainfall than evaporation over the year.

But the matter goes deeper than just the ocean surface water, says Durack. The ARGO buoys don't just float around on the surface, they can sink down to two kilometers below the surface and rise again, gathering data the whole way to create three dimensional ocean profiles. These show that the salinity changes are actually moving, following the paths that ocean water circulates from the surface into the depths.


"While such changes in salinity would be expected at the ocean surface (where about 80 per cent of surface water exchange occurs), sub-surface measurements indicate much broader, warming-driven changes are extending into the deep ocean," said Durack."

Fortunately there's one salinity sensing satellite in orbit now (ESA's SMOS), and the U.S. competitor (Aquarius) is getting nearer to launch. So we'll be able to keep trace of this issue quite well. Hopefully that will help.

No comments: