Sunday, May 23, 2010

Sea ice grab bag

Does anyone remember "José Chung's From Outer Space" that great early episode of the X-files in which Daniel Quinn (pictured above) is found by the side of the road in an alien body suit repeating "This is NOT happening!" over and over?

Well, evidently Mr. Steve Goddard is channeling Mr. Quinn's character, given his latest "Sea ice update," which opens:

The Arctic is still running well below freezing, and as a result there just isn’t much happening.

Uh, Steve? Are you looking at your own graphs?

We are not only trending below all of the three worst years for the summer minimum (2007, 2008, and 2009); we've also fallen more than two standard deviations below the already-low 1979-2009 average.

Cryosphere today (a different dataset using a different definition of ice cover) is now showing the ice at 987,000 square km below the 1979-2009 average. In the last month the anomaly has gone from near-zero to almost a million square kilometers missing. Where's the ice, Steve? And how is a million square kilometers of missing ice nothing much happening?

How on Earth does Goddard rationalize these developments as "nothing much"? His method is quite amusing. For example, take this delicious bit of denier logic, from last week's update:

As in past weeks there is excess ice in the Bering Sea and Sea of Okhotsk, and a deficiency in the Barents Sea – which are all always ice free during the summer anyway.

Oh, well if they always melt anyway . . . not. Sorry, Steve, but ice melting doesn't work like that -- certain parts of the ice field are not labeled "melt" and "non-melt," like furniture tagged for movers. Heat energy is absorbed by the ice during the warm season, and it breaks up and melts from the outside edge inwards. More ice melting at an earlier data means more of that heat energy will be delivered to the interior later in the season. "Oh, all this stuff melts anyway" is the sort of science-illiterate statement WUWT has elevated to an art form.

This week Steve's back with another priceless effort at rationalization; it's not global warming, it's warm water:

The Alaska side has above normal sea ice and the Greenland side has below normal sea ice. This is a reflection of ocean temperatures, which are below normal in the North Pacific, and above normal near Greenland.

Of course, where does >90% of the excess heat trapped by AGW go? Into the oceans of course. And the warm oceans help melt the ice. But temperatures are below average somewhere! Or average. Well, not really average, even, but warm:

Hard to know where Steve sees the average temperatures -- the whole Arctic looks pretty hot to me, and he doesn't source the assertion.

While we're talking sea ice, I thought it might be useful to point out why we suffer this yearly braying about sea ice extent being "near average." Seasonal sea ice extent looks like this:

You can see the summer trend is far greater than the winter trend, although extent is down in every season. This chart helps clarify mattters:

The ice extent predictably approaches the average in the winter, before falling far below it in the summer. To illustrate why this is, fill an ice tray with water, stick it in the freezer, and come back in a half an hour. What do you have? A thin coating of ice over the surface of the water. It takes very little cold to create that thin sheet of ice -- and it takes very little heat to melt it.

This is where we are at with the Arctic today. The good ice, the thick multiyear stuff, has been decimated. That is why Arctic ice volumes are at their lowest level ever; that is why the summer always brings minimum sea ice extents far below average. But no matter how much melts in summer, it takes a trivial amount of cold Arctic night to form a thin layer of what scientists in the Arctic are calling "rotten ice" -- and the satellites which measure the surface area pick up a near-extent in winter, when the reality is, the ice is not normal at all. The winter ice extent numbers are like the infamous single hundred-dollar bill covering a stack of newspaper. The summer heat, like a diligent gangster, quickly breaks apart the pack and uncovers the truth.

It's bad news for the earth, but for sheer entertainment value, it's hard to beat Steve Goddard is his rubber suit, rocking back and forth and chanting "It's not happening. It's NOT happening."

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