Thursday, November 07, 2013

Oh, Yippee! Let's Hit the Beach.

Just kidding.   This is nothing to cheer about.   The Pacific Ocean is now warming 15-times faster than normal.  From

Average global surface-air temperatures have been rising at a slower rate than some climate scientists projected. A reason, as a new study published in Science on Thursday helps demonstrate, is that the oceans have been absorbing much of the heat.

The fact that the oceans are warming has already been established. As Grist’s John Upton explained earlier this year, previous studies have measured oceanic temperatures every year for the last few decades and demonstrated that the oceans are warming.

What the new paper — “Pacific Ocean Heat Content During the Past 10,000 Years” — shows is that the recent oceanic warming is happening at a historically unprecedented rate. The study was authored by three researchers: Braddock Lindsay, a geoscience researcher at Columbia University; Delia Oppo, a climate scientist at Woods Hole Oceanographic Institution; and Yair Rosenthal, a geologist at Rutgers.

What they find is that there was a warm period between 10,000 and 8,000 years ago, then a longer period of lower temperatures, and a rise of about 0.5 degrees Celsius that started sometime between 1,600 and 1,800. So that’s a half-degree increase over the last 200 to 400 years. While the amount of change is not greater than some historical variations, the rate of change is unnaturally fast. “That rate of change in ocean heat content is 15 times greater now than it’s been in the last 7,000 or 8,000 years,” notes Lindsay.

Here’s how it works: At mid and high latitudes, surface water heats up due to atmospheric warming, then it sinks. Over decades these warmer waters will also work their way toward the Equator. “Our [samples] are only from Indonesia in a place where intermediate water from both the North and South Pacific flows into the Indian Ocean,” says Lindsay, “so it’s an especially good place to measure these developments.”

The research dealt strictly with ocean temperatures and did not extend to the impacts on marine life or the associated acidification and creation of dead zones.   Those rosey chapters are being written by others including the NOAA.


Al Hunter said...

I'm probably missing something obvious, but "surface water heats up due to atmospheric warming, then it sinks" is a confusing statement. I thought cold water sinks, unless it gets frozen & then it floats.

The Mound of Sound said...

It's a common mistake, Al. Warm water is heavier which is why lakes don't freeze from the bottom and all those fish get to live through the winter. It has something to do with the way the molecules are configured by temperature.

Last week I read an explanation of the physics that cause hot water to freeze faster than cold water. It sounds so counterintuitive but it's true.

Anonymous said...

Just imagine....the oceans are heating up from the bottom. Poor hot weter into a bucket of cold water and see what happens to it....dah!! Anyone raised near oceans or played in them know this.

The Mound of Sound said...

No, Anon, the oceans aren't 'heating up from the bottom.' With the exception of the odd vent, there's no heat source on the sea bed. You need to read a bit about the ocean conveyors. As for "pooring" hot "weter" into a bucket of cold water, what would you possibly hope to learn from that? You can't create either currents or temperature gradients in a bucket of water. Anyone raised near a bucket of water should know that.