Sunday, November 16, 2014

Hot acid: where our Hawaiian oceans are going

Dumping greenhouse gases into the atmosphere doesn’t just cause atmospheric warming.

It causes lots of effects, some of them catastrophic in dramatically different ways. 

But heat is a big one all by itself, and it gets not only into the atmosphere, but into the seas. The oceans are now warmer than at any time since water temperature has been recorded.

(Image: At left, ocean temperatures, showing the rise since the beginning of the industrial age n the 1800s. The vertical green stripe at right is the 2000-2013 pause. At right, yellow and red show waters that are warmer than the long-term mean. Credit: IPRC.)

This summer has seen the highest global mean sea surface temperatures recorded since their systematic measuring started. 

“The 2014 global ocean warming is mostly due to the North Pacific, which has warmed far beyond any recorded value and has shifted hurricane tracks, weakened trade winds, and produced coral bleaching in the Hawaiian Islands," said Axel Timmermann, a climate scientist with the International Pacific Research Center at the University’s Mānoa campus.

Already-warm ocean temperatures stabilized from 2000 to 2014, then began heating up further earlier this year. (The pause invigorated climate change deniers, who famously trumpeted the stabilization as proof that warming had stopped. Unfortunately, they were once again wrong.)

(Image: Hawai`i sits in a pool of warm water. This is a NOAA image showing temperature anomalies in the central Pacific as of November 13, 2014. Once again, yellow and orange represent waters warmer than the long-term normal. Credit: NOAA/NESDIS.)

A University of Hawai`i press release describes the pattern:

“Sea surface temperatures started to rise unusually quickly in the extratropical North Pacific already in January 2014. A few months later, in April and May, westerly winds pushed a huge amount of very warm water usually stored in the western Pacific along the equator to the eastern Pacific. This warm water has spread along the North American Pacific coast, releasing into the atmosphere enormous amounts of heat—heat that had been locked up in the Western tropical Pacific for nearly a decade.”

“The warm temperatures now extend in a wide swath from just north of Papua New Guinea to the Gulf of Alaska,” Timmermann said. 

And of course, warmer waters aren’t all that’s going on in the oceans. There’s sea level rise. And changes in current patterns. And shifting of nutrients that in turn affect fisheries. And lots more. Ocean acidification is still another big one.
The excess of carbon-dioxide in the atmosphere is mixing into the oceans along with the heat, and acidifying the water. That has dramatic impacts on the survival of various kinds of marine life, including coral reefs, shellfish and a lot of tiny marine animals that are basic to the oceanic food chain.

If you're interested, here is a good resources on that issue. 

© Jan TenBruggencate 2014

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