Deep Antarctic waters freshening

Daily Telegraph (UK): Scientists studying the icy depths of the sea around Antarctica have detected changes in salinity that could have profound effects on the world's climate and ocean currents. The scientists returned to Hobart on Thursday after a one-month voyage studying the Southern Ocean to see how it is changing and what those changes might mean for global climate patterns.

Voyage leader Steve Rintoul said his team found that salty, dense water that sinks near the edge of Antarctica to the bottom of the ocean about 5 km down was becoming fresher and more buoyant. So-called Antarctic bottom water helps power the great ocean conveyor belt, a system of currents spanning the Southern, Pacific, Indian and Atlantic Oceans that shifts heat around the globe.

"The main reason we're paying attention to this is because it is one of the switches in the climate system and we need to know if we are about to flip that switch or not,'' said Rintoul of Australia's government-backed research arm the CSIRO....

Antarctic circumpolar current, NASA/JPL Caltech, Wikimedia Commons