Arctic sea ice set a record minimum extent in September 2012, far
below the previous record low in 2007. Summer extents have been far
lower than average for the last decade, with several record or
near-record years. Looking at the numbers, one is tempted to think that
the Arctic Ocean may reach nearly sea ice-free conditions within just a
few years. But most expert analyses indicate that we’re likely at least a
couple decades away from seeing a blue Arctic Ocean during the summer.
So what is going on here? Readers have asked if scientists are being
too conservative in their assessment of the recent ice loss. We asked
Walt Meier, NSIDC scientist, to address this question. Following is his
While keeping an eye on day-to-day data and speculating about whether 2013 is going to overcome the odds and break last year's records, one tends to forget about the wider implications and what this actually is all about. A tree is incredibly interesting, but in the end it's all about the forest.
It's important to remember that the situation isn't looking good in the Arctic. Not good at all. We're witnessing things that were supposed to happen decades from now. Instead we're looking at a change that is hard to fathom, but takes place during our lifetimes, not on a geological timescale.
Last year Kevin McKinney and I wrote a piece about the potential consequences of all this, and I'll be sure to get back to it at the end of this melting season (and the next, and the...), but in the meantime here's what Gareth Renowden of the Hot Topic blog, one of the first bloggers to pay attention to the Arctic situation, has to say about it:
This should be headline news. It should be plastered all over the front
pages of newspapers and web sites around the world. TV pundits should be
demanding action from the politicians who have put action on emissions
reductions in the “too hard” basket. The evidence is beginning to
suggest that Wally Broecker’s angry beast,
fed up with being prodded with ever bigger sticks, is going to bite
back hard — and bite back soon. Is there time to stop all this
happening? Perhaps — but it will take a huge effort, a wartime response
when the world is being led by billionaires, ideologues and their
appeasers intent on denying reality. We’re sleepwalking to disaster. By
the time we wake up, it will be too late.
This was Gareth's conclusion. Here's what led him to it:
There's another storm brewing in the Arctic, the second this year after PAC-2013, the persistent Arctic cyclone that stayed in place for weeks on end and caused the first half of the melting season to be very slow. And also the second storm after last year's Great Arctic Cyclone, the iconic image of which is shown to the right (source: UCAR's AtmosNews).
The ice pack will probably be able to withstand the storm better than last year because there's more ice and it looks less patchy. Besides, the storm is occurring two weeks earlier, and won't match GAC-2013 in duration or magnitude. Nevertheless, this as of yet unnamed storm (a tradition we're trying to start over here on the ASIB) will probably become intense enough to leave a mark on the ice, which is why I decided to dedicate a blog post to it.
To see what we're talking about, here's the SLP map from the Danish Meteorological Institute, with the cyclone in question, getting ready for two big days:
I made this panel that shows the ECMWF weather forecast for the coming 4 days (click for a bigger version):
The Arctic is about to welcome another big cyclone. Though probably not as large, intense and long-lasting as last year's Great Arctic Cyclone, it is rather intruiging to see a cyclone of similar magnitude occur so soon after the last one. It makes one wonder whether the Arctic will be seeing more of these cyclones in years to come. And if so, perhaps they should get names.
This is discussed by R. Gates in the guest post below.
To name or not to name? And if so, what to name? I must admit that I have a bit of bias on this issue, as it was my posting here in 2012 that came up with the name of the "Great Arctic Cyclone of 2012". Now of course, we even have a Wiki link on it.
Just to remind some of you of the scope of the unusual summer Arctic storm. It was a monster, by any standard:
The issue now is whether it is time to begin to officially name these storms something a bit more interesting than GAC-2012, or PAC-2013, etc. The underlying assumption may be that these "very rare" events of large summer cyclones may in fact become more common as the northern hemisphere climate and specfically the Arctic rapidly change into a new regime due to Anthropogenic forcing. This assumption, may or may not be valid, though there is some research to back it up.
During the melting season I'm writing (bi-)weekly updates on the
current situation with regards to Arctic sea ice (ASI). Central to
these updates are the daily Cryosphere Today sea ice area (SIA) and IJIS sea ice extent (SIE) numbers, which I compare to data from the 2005-2012 period (NSIDC has a good explanation
of sea ice extent and area in their FAQ). I also look at other things
like regional sea ice area, compactness,
temperature and weather forecasts,
anything of particular interest.
The animation on the right consists of NSIDC sea ice concentration maps, one for each ASI update.
Due to technical problems, a video will be posted later today or tomorrow.
Two weeks ago I said: Bye bye, Beaufort. But the ice in the Beaufort didn't really wave back. It retreated somewhat, but much less than I expected after a full week of ideal conditions. At the end of winter the ice was supposed to be thinner there than last year (when it retreated at an amazing pace) and it currently looks extremely mushy out there, individual floes can hardly be made out. But somehow the ice pack is standing its ground in that part of the Arctic.
Nevertheless, with all the easy ice melting out elsewhere, trend lines on extent and area graphs plummeted, and 2013 slashed some of the difference with previous record years 2007, 2011 and 2012. However, with most of the easy ice now gone and ideal conditions fading out in the past couple of days, things have started to slow down.
There's still a lot of melting potential around (and within) the pack, and with a potentially big cyclone forecasted to form in a couple of days, there's no telling what can happen.
Sea ice area (SIA)
has had several big melting periods this month (13 century breaks in 19 days), albeit interspersed with some slow days, and so a very high rate of daily decrease (only 2009 comes close) has brought 2013 real close to 2007 and 2011, and the difference with 2012 has been reduced further to a little over 500K.
Arctic Sea Ice Blog commenters come up with all kinds of ways to make sense of or visualize what's going on with the ice pack, tweaking satellite data, 'declouding' images or compiling animations. In this blog post I want to show a couple of those efforts.
Commenter Danp opened a thread on the ASIF a couple of days ago, showing a cleaned up compilation he made of LANCE-MODIS satellite images (like commenter dabize did last year). The result looks very nice indeed, giving us a clear view of the holes on the Atlantic side of the Arctic, near the North Pole:
You can go to Danp's Google Drive image and zoom in up to a 500m resolution.
Commenter A-Team, of course, keeps rocking hard with his infinite ways of tweaking images to squeeze info out of them. His latest creations can be admired in the recent Nares blog post, but here's one interesting example:
In mid-June through early July, participants on the Arctic Sea Ice (ASI) blog posted 82 individual predictions for the mean NSIDC September Arctic sea ice extent. The median value of these 82 predictions was 3.2 million km2, with an interquartile range (approximately the middle 50% of predictions) from 2.7 to 3.9 million km2.
Medians and quartiles are employed as basic summaries here because they offer high resistance to outliers, are easy for anyone to replicate, and map into more detailed analysis using graphics or quantile regression. Individual predictions ranged from 0 to 5.6 million km2. A stem-and-leaf display compactly shows the distribution:
Title and image both stolen from Espen on the Arctic Sea Ice Forum:
Nares Strait is an old favourite on the Arctic Sea Ice blog, because every year it's a surprise when the ice arch/bridge - preventing ice transport from the Lincoln Sea towards Baffin Bay - is going to collapse. This year it happens almost two weeks later than last year, which in its turn was 10 days later than in 2011. What strikes me this year, and maybe I didn't pay enough attention in previous years, is that the break-up was already occuring from within through in situ melting, before the arch gave way.
Ice transport through Nares Strait contributes to ice loss from the
Arctic Basin. It it isn't quite as significant as ice transport through
Fram Strait (roughly 10% at the most), but the ice that gets
transported, is some of the thickest and oldest ice in the Arctic. A
NASA-led study by Ron Kwok in 2010 (PDF) showed that transport in 2007 was exceptionally high.
It's been a while since we've looked at methane trends in the Arctic atmosphere (just a little under a year in fact). This important greenhouse gas has been on the rise over the past several decades, though that rise has not been nearly as steady as CO2. What's worrisome to those who follow methane is the return to higher growth rates of the gas over the past few years. This chart shows the atmospheric measurement of methane at Point Barrow cover the last 2.5 years:
What I've highlighted here in red are a few interesting features of the methane levels that are worth mentioning.
First, the horizontal red bar shows the lowest boundary of the yearly methane measured a few weeks ago. Methane always hits a low annual concentration at Point Barrow around the middle of the year, usually in June as part the natural fluctuations. This year we saw the highest low point ever recorded. This is significant because it shows the underlying long-term growth rate. If you compare this year's low point to last year's, you get a sense of the upward turn in the atmospheric methane concentrations.