With records being shattered all over the place, some names in the cryospheric community are gaining in prominence. One of those names is Peter Wadhams, professor of Ocean Physics at the University of Cambridge, who has been predicting for years the things we are currently witnessing. He already was a prominent expert, allowed to hop on British submarines to measure Arctic sea ice thickness from below, leading him to conclude in 1996 that Arctic ice had thinned by 40 per cent since the 1970s. But he is one of the few scientists to come out early and warn about the impending disappearance of Arctic sea ice and its consequences.
BBC Newsnight has more from Professor Wadhams:
Arctic ice melt 'like adding 20 years of CO2 emissions'
Loss of Arctic ice is effectively doubling mankind's contribution to global warming, ice scientist Professor Peter Wadhams has told BBC Newsnight.
White ice reflects more sunlight than open water, acting like a parasol.
Melting of white Arctic ice, currently at its lowest level in recent history, is causing more absorption.
Prof Wadhams calculates that this increased absorption of the sun's rays is "the equivalent of about 20 years of additional CO2 being added by man".
The Cambridge University expert says that the Arctic ice cap is "heading for oblivion".
In 1980, the Arctic ice in summer made up some 2% of the Earth's surface. But since then the ice has roughly halved in area, and the volume of ice has dropped to just a quarter of what it was.
"The volume of ice in the summer is only a quarter of what it was 30 years ago and that's really the prelude to this final collapse," Prof Wadhams said.
The polar ice cap acts as a giant parasol, reflecting sunlight back into the atmosphere in what is known as the albedo effect.
But white ice and snow reflect far more of the sun's energy than the open water that is replacing it as the ice melts.
Instead of being reflected away from the Earth, this energy is absorbed, and contributes to warming.
Parts of the Arctic Ocean are now as warm in summer as the North Sea is in winter, Prof Wadhams said.
There's some more on the implications of disappearing Arctic sea ice for the UK. Read the whole article here.
I'm sure professor Wadhams will have a paper out to substantiate this claim, but take out your calculators and start crunching, boys and girls.
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Also see this excellent article on ClimateProgress, quoting several other ever more prominent names, like Wieslaw Maslowski:
Regardless of all these uncertainties and for the record, if any of these estimates of arctic sea ice volume decline is close to reality, a near ice-free Arctic in summer can happen not in 2100, 2050 or 2037 but much sooner. One of the main reasons I believe it will happen sooner (i.e. the trend of sea ice volume decline will continue) is that with the shrinking sea ice cover in summer the Arctic Ocean increases its net annual heat content through absorption and redistribution, especially in the upper water column, below the surface mixed layer.
This constitutes a positive feedback to sea ice melt in addition to ice-albedo and other feedbacks, mainly because it can affect the sea ice cover year around, including in winter through upward heat entrainment and reduction of ice growth. The warmer Arctic Ocean can also affect air temperatures and circulation, not only during freeze-up but also in winter and spring. Observational evidence (Jackson et al., 2010 and 2011) suggests increasing sub-surface temperatures and over increasing area in the Canada Basin through 2009, which independently of models supports the argument about the increasing upper ocean heat content.
I do realize that the above sounds ‘alarmist’ and I’ve heard such criticism more than once before but I believe it’s my obligation to make sure that this message is heard by the policymakers and general public.
Read the whole article here.
Talk of jetstreams, Hudson has just published another jetstream paper - (Measurements of the movement of the jet streams at mid-latitudes, in the Northern and Southern Hemispheres, 1979 to 2010 - PDF) showing their pole-ward movement using ozone data. After a very quick skim, I note he gives a figure for the sub-tropical jetstream movements (The tropics have expanded 10 deg of latitude over the period = 40km per year, although Northerners may be relieved to hear that is 2:1 a southerly movement).
Sadly no equivilant figure can be given for the polar jetstreams as the data only extends to 60 deg N&S, although Table 2 quantifies the effect up to 60 deg N&S.
Posted by: Al Rodger | September 08, 2012 at 10:47
It may be thinner (in km's) but it is denser (in kg/m3, cause it is colder) in the troposphere.
Gravity effect are about 0.5 %, far smaller than the temperature effect.
I think these would make the optical density actually larger from line broadening.
But, as indicated, there are other reasons like water vapor that make the optical density actually smaller.
Posted by: Wipneus | September 08, 2012 at 11:33
Hi Al,
This topic will be important for Winter 2012/13. Here's a recent paper:
Francis et.al (2009) "Winter Northern Hemisphere weather patterns remember summer Arctic sea-ice extent" (pdf)
From the Abstract:
Here's an example of what happens to the atmosphere in high-ice years (red) vs. low-ice years (blue), from Fig. 3:
Figure 3. Poleward gradient in the geometric thickness of the 1000-500 hPa layer [m km1] in (left) the North Atlantic and (right) the North Pacific Oceans during years with above- (red) and below-normal (blue) sea ice during summer. Data extend from September of the extreme ice year to the following March.
Here's the full Citation, with a GRL link:
Francis, J. A., W. Chan, D. J. Leathers, J. R. Miller, and D. E. Veron (2009), Winter Northern Hemisphere weather patterns remember summer Arctic sea‐ice extent, Geophys. Res. Lett., 36, L07503, doi:10.1029/2009GL037274.
Cheers,
Lodger
Posted by: Artful Dodger | September 08, 2012 at 11:53
Hi Wipneus,
This is something I should ask Wayne Davidson, but I think that arctic aerosols are a major factor in the lower optical depth of the Northern atmosphere.
Aerosols are monitored by AFI at Ny-Ålesund, Spitsbergen and by NOAA at Barrow, Alaska. I'll be watching the changes as development comes to the North.
Cheers,
Lodger
Posted by: Artful Dodger | September 08, 2012 at 12:05
Artful Dodger,
Check the main graphic of Neven's post, Signs of Artic Change. You mentioned the position of the Jetstream w.r.t. the AUgust storm. This year's summer low pressure anomaly around the Greenland high produced a band that tracked the progress of the Arctic low that produced the August storm. Most years the pattern tracks lows across the land of Siberia.
Posted by: Chris Reynolds | September 08, 2012 at 12:20
Hi Chris,
There was only one jet core present in the Central Arctic on Aug 3-4, 2012. Look at this series of charts of the polar jetstream:
12080300
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12080412
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The GAC2012 event was not simply a surface low pressure system. It also had a considerable depression at the 500 mb level (18,000 ft or 5.5 km pressure altitude).
It's this higher level of the atmosphere that the polar jetstream helped to spin up, and contributed to the formation, and the strength, of GAC-2012.
Cheers,
Lodger
Posted by: Artful Dodger | September 08, 2012 at 13:26
Peter Wadhams speculative calculation does not work in the real world, since extra heat absorbed due to albedo change stays in the Arctic. This is from the abstract to Kumar et.al (2010) "Contribution of sea ice loss to Arctic amplification"
Heat does not move against a temperature gradient. It always flows from warmer to cooler. As long as the Arctic is cooler than the South, the heat stays put, or is radiated to space (the next coolest place).
It's like trying to paint your attic by splashing paint in the basement. It don't work. At least not until the basement is full.
Give it perhaps 40 years, this will be an issue after the Winter ice disappears. Then the Arctic ocean may be warmer than peripheral seas at the end of Summer, and heat/water vapour will flow downhill...
Posted by: Artful Dodger | September 08, 2012 at 13:40
"Heat does not move against a temperature gradient. It always flows from warmer to cooler. As long as the Arctic is cooler than the South, the heat stays put, or is radiated to space..."
But a lot of the heat gained in the tropics is transported to the poles before being radiated into space - and with warmer poles, and lower gradient, less gets transported poleward. Jacking up the temperature locally at the poles by decreasing albedo results in less transport of heat poleward and warmer temperatures globally even without any changes elsewhere.
I wonder if the larger annual variation in ice freeze/melt will cause large annual cycles in the AMOC, and if more open (esp. summer) water will change the balance between latent and sensible heat transport in the atmosphere - with concomitant changes in the weather.
Posted by: Bdwo | September 09, 2012 at 22:18
Was a nice surprise to see Newsnight used my animation, even if they didn't use my proper name!
Updated version to Sep 2nd:
http://youtu.be/EnCy-R7mLHI
Posted by: Andy Lee Robinson | September 10, 2012 at 22:48
Lodger,
Nice sketch, what is missing or needs correction is the 45 N bit, and also the extra cyclones brought by the Jet stream at 70 N. and Northwards. These cyclones are brought up because its warmer from over all thinner ice during winter, and from wider open sea surface during summer.
I like the solar insolation bit, you may add the atmosphere is much much cleaner up here, making an even smaller OD.
Posted by: wayne | September 11, 2012 at 03:36
Thanks, Wayne.
Enjoyed your post on the 'cold North pole'. I think this has huge repercussions for the ultimate fate of the pack ice North of Greenland/Ellesmere Island.
A persistent high over BG, combined with frequent lows over the central pack due to open water, means a reversal of the normal clockwise rotation of the gyre.
Inside, c-clockwise rotation leads to sea ice advection through Fram strait of the oldest sea ice, instead of its preservation.
A catastrophic change over a decadal timescale, but already visible in its effects this year:
http://iabp.apl.washington.edu/maps_daily_tracknsidc.html
Stay frosty, mate!
Cheers,
Lodger
Posted by: Artful Dodger | September 11, 2012 at 11:19
Lodger
The flow of ice in the remaining pack is really odd, out of normal especially along the Archipelago NW coast. unrecognizable is a better word. Yet the ice extent melt was greater than sunnier 2007. This points out solidly to an irreversible downward melt rate. Sorry about the summer rain projection for UK and Ireland, but is likely that winters will be milder and more frequently settled.
Posted by: wayne | September 11, 2012 at 14:23
Peter Lilley the rent a quote skeptic brought in for this TV program has an interesting new job.
Recently appointed non Executive Chairman of an oil exploration company.
Hat tip to Leo Hickman.
http://www.tethyspetroleum.com/tethys/newscontent.action?articleId=2355562
Posted by: dorlomin | September 11, 2012 at 19:11
Congrats, Andy Lee. Your 3D sea ice volume video has been featured on Joe Romm's Climate Progress Blog. Well done!
http://thinkprogress.org/climate/2012/09/11/832161/arctic-death-spiral-the-video/
Looking forward to your '3D Death Spiral' video!
Cheers,
Lodger
Posted by: Artful Dodger | September 12, 2012 at 01:35
Thanks Lodger - let's hope it'll go viral and draw attention to what is really happening up there.
The new one is still in development - not a trivial process with thousands of parameters to play with, but hope it'll be ready soon.
Posted by: Andy Lee Robinson | September 12, 2012 at 06:17
Great work, Andy. Sorry for not giving it a platform on the blog here. I was too busy and then forgot about it. I'll post the new one in a separate blog post as soon as you're done.
Posted by: Neven | September 12, 2012 at 11:05
Andy Lee,
As well as BBC2's Newsnight, I would also expect to see your excellent PIOMAS animation appearing on the "BBC documentary entitled 'Operation Iceberg', to be broadcast in October," that was announced within the Susan Watts item on Newsnight (& which the Newsnight item appears to have been compiled from).
Posted by: Al Rodger | September 12, 2012 at 12:23
Carbon Brief have posted a transcript of the Newsnight Programme. They do describe it as "a rough transcript" elsewhere on their site, so be warned. One correction I spot from the off - Natalie Bennett is not an MP. She did try in 2010 in 'Holborn & St Pancras' but only came 4th. (Her predecessor was the MP.)
http://www.carbonbrief.org/blog/2012/09/transcript-newsnight-on-the-arctic
Posted by: Al Rodger | September 12, 2012 at 13:23
Hi Andy Lee,
Carbon Brief have a vistor from the BBC production team on their comment thread.
I mentioned (& linked) your up-thread "jolly complaint" about not using your real name.
http://www.carbonbrief.org/blog/2012/09/bbc-makes-a-locally-sourced-meal-of-discussing-arctic-sea-ice-melt#comment-653018607
Posted by: Al Rodger | September 17, 2012 at 13:30
Neven, thanks - I'll let everyone know here. Hope you enjoyed your holiday in spite of its timing!
Al, thanks for your support and the plug. I am following the carbonbrief article too, suffering from information overload with 200+ open tabs, and many distractions managing my servers!
I think I've read every twitter message that has ever been posted since July!
I'm not too bothered about attribution — visceral satisfaction is enough — the main thing is that it gets seen and shared by as many people as possible.
Posted by: Andy Lee Robinson | September 19, 2012 at 07:20