The state of the Arctic in August 2009 is among the worst in recorded history. Arctic areal sea ice extent won’t break the 2007 record, but it’s nowhere near the climatological average – and that’s indicative that a new phase of the Arctic has been reached. For three years in a row, sea ice extent has bottomed out at well below two standard deviations from the average extent. The biggest difference between this year and 2007 is the shift of local weather patterns. This year, a high pressure system has kept moving ice toward cooler water near the Siberian coast rather than away from the Siberian coast. I’ll share some graphical images, then discuss them and the larger picture below.
Here is my last post showing conditions in July and June. Conditions have steadily worsened throughout this summer, as the pictures below demonstrate. As of yesterday, here is a satellite representation of Arctic sea ice conditions:
And here is the comparison picture from July:
Here is the time series graph for August:
And the same graph from one month ago:
The NSIDC released a report mid-month with an additional time series representation of conditions. It shows the past three years’ worth of data with +/- 2 standard deviations from the climatological average on the same graph:
As you can see, conditions this year resemble the past two years pretty well. I think the Arctic has experienced a fundamental shift in its characteristics. I think a tipping point has already been passed. I think we’ll see Arctic conditions like this or worse in the years to come.
This years’ melt season isn’t over – there is probably 3-4 weeks left. The rate might not be as rapid as it was earlier this summer, but I think a slowing melt will occur over the next month. Regardless, areal sea ice extent in the Arctic is far below the climatological minimum that normally occurs in the next week or two. Instead of 7 million sq. km., however, we’re likely to see a minimum of 5 million sq. km. That’s a huge difference!
Despite the minutiae of the specific numbers and weather patterns one year versus the next, the large message is this. Multi-year ice has decreased in recent years. Ice that is younger than one or two years old melts fastest each summer. The heat content in the Arctic ocean is increasing. That heat has to go somewhere. It has held back ice reformation the past two winters. As a result, the Arctic continues to warm each year faster than the rest of the planet.
To a lesser degree, some of the the heat has also been transported out of the Arctic. Now, the world’s oceans are big. But a continuation of increased heat content will continue to impact the globe in additional feedback processes. The ocean will continue to expand as heat is added to it. As water underneath ice at both poles becomes warmer, sea-based ice melts from below as well as above. As sea levels rise, land-based ice becomes threatened. Methane plumes become active and release long-frozen gas hydrates to the ocean and atmosphere. The atmosphere and ocean continue to warm. And so on.
I would also like to recommend taking a gander at billlaurelMD’s Arctic diary from Monday at The Big Orange. He’s got some nice graphs that show surface and ocean conditions.
Will American legislators do something about the clear signals that have been announced for years? Or will they continue to sell themselves out to the highest bidder – which is never the American citizen?
Cross-posted at SquareState.