While the anti-science crowd scours the globe desperately looking for any indication of their imaginary cooling, reality has intruded again.
Because they and the media — and even some scientists who don’t follow the subject closely — tend to take a two-dimensional view of the Arctic, they along with much of the public have been fooled into thinking the Arctic “recovered” in the past two years because sea ice extent appeared to recover. Heck, some even claimed last month the Arctic ice was “recovering” to the 1979-2000 average.
Climate Progress readers have long understood that trends in multi-year ice — ice volume — are what matter most in terms of the long-term survivability of the Arctic ice in the summer (see New study supports finding that “the amount of [multi-year] sea ice in the northern hemisphere was the lowest on record in 2009″).
CP readers have also understood that Arctic volume did not recover in the last two years. Quite the reverse — we appear to have been breaking volume records over the past several months according to the Polar Science Center:
Total Arctic Ice Volume for March 2010 is 20,300 km^3, the lowest over the 1979-2009 period and 38% below the 1979 maximum. September Ice Volume was lowest in 2009 at 5,800 km^3 or 67% below its 1979 maximum.
That is, in September, PSC says we saw the lowest volume ever, and in March, we saw the lowest volume for that month, according to their Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS). Cryosphere scientists I have spoken to say PIOMAS is best for showing long-term trends, and they do recommend the caveat that it is a model, and so conclusions should be viewed accordingly. That said, as the website shows, the analysis has been validated.
I would also note that even the sea ice area measurements are based on remote data that must be interpreted using models. A recent study, “Perennial pack ice in the southern Beaufort Sea was not as it appeared in the summer of 2009” by Barber et al. suggested that satellite (and other) measurements of Arctic sea ice extent were apparently deceived into OVERestimating summer sea ice extent in 2009:
In September 2009 we observed a much different sea icescape in the Southern Beaufort Sea than anticipated, based on remotely sensed products. Radarsat derived ice charts predicted 7 to 9 tenths multi-year (MY) or thick first-year (FY) sea ice throughout most of the Southern Beaufort Sea in the deep water of the Canada Basin. In situ observations found heavily decayed, very small remnant MY and FY floes interspersed with new ice between floes, in melt ponds, thaw holes and growing over negative freeboard older ice. This icescape contained approximately 25% open water, predominantly distributed in between floes or in thaw holes connected to the ocean below. Although this rotten ice regime was quite different that the expected MY regime in terms of ice volume and strength, their near-surface physical properties were found to be sufficiently alike that their radiometric and scattering characteristics were almost identical.
Last week, Arctic explorers again reported conditions they did not expect:
A group of British explorers just back from a 60-day trip to the North Pole said on Monday they had encountered unusual conditions, including ice sheets that drifted far faster than they had expected.
The three-member team walked across the frozen Arctic Ocean to study the impact of increased carbon dioxide absorption by the sea, which could make the water more acidic and put crucial food chains under pressure.
Expedition leader Ann Daniels said the ice drifted so much that they eventually covered 500 nautical miles (576 miles) rather than the 268 nautical miles initially envisaged.
One possible reason for the rapid drift was a lack of ice, she suggested. Satellite imagery reveals rapidly melting ice sheets in the Arctic, a region which is heating up three times more quickly than the rest of the Earth….
“None of us had ever experienced that amount of southerly drift on our previous expeditions, and it continued for such a long period of time. We kept expecting it to stop, we began to pray it would stop,” Daniels said….
Many scientists link the higher Arctic temperatures to the greenhouse gas emissions blamed for global warming….
Ah, those blame-mongering “many scientists.” Seriously, Reuters, can’t we get something just a little better than three hedges — “many” and “link” and “blamed”? Can’t we get by with, say, just one friggin’ hedge? (Plus that sentence as written makes no sense — The higher temperatures are the same as global warming)
How about “Many scientists say the higher Arctic temperatures are from global warming caused by greenhouse gas emissions”? How about no hedges: “Climate scientists say the higher Arctic temperatures are from global warming caused by greenhouse gas emissions.”
The story continues
“We spent a couple of days walking on ice that was three or four inches thick with no other thicker ice around, which was a big surprise to us,” he told the news conference….
Last month explorers at the team’s ice base some 680 miles (1,100 km) further south reported a three-minute rain shower, which they described as a freak event.
It’s time to stop being surprised by the fact that the ice is so damn thin — see my May 2009 post, North Pole poised to be largely ice-free by 2020: “It’s like the Arctic is covered with an egg shell and the egg shell is now just cracking completely.”
And it’s time to stop calling extreme weather “freak events.” But I digress.
The PIOMAS analysis appears to be the best volume model around, and here is their latest anomaly graph:
Note: “Anomalies for each day are calculated relative to the average over the 1979 -2009 period for that day to remove the annual cycle.” The sharp drop at the end is not to a record low absolute level of ice volume, but to apparent record low for the month.
So, will we see a record low area and record low area this year?
One cryosphere scientist I e-mailed who doesn’t want to make predictions on the record thinks we’re on track to beat last year’s area and hit the 2008 level — unless we get the same kind of weather pattern that we had back in 2007, in which case we would set the record and perhaps by a very large margin. Note that although we are apparently below 2007 sea-ice area now, we aren’t at the record low area for this month (click here).
The volume record seems more probable given where the sea ice extent is now compared to 2007 and how much less volume we appear to be starting with right now. Of course, the sea ice extent is more visible and anything less than the record of 2007 will no doubt be dismissed by some. But at least with the the Polar Science Center work, we will have a nearly contemporaneous, well-validated model to track the volume.
I still like my odds on a 90% ice free Arctic by 2020 (see “Another big climate bet — Of Ice and Men“).
[Note: Any reader who is good at data graphing, please email me here.]