Arctic sea ice continues to recover - should we be worried?
The most recent update of Arctic sea ice volume on August 22nd shows that it's recovered above the previous record low in 2007 (again). http://nsidc.org/data/seaice_index/images/daily_im...
Should we be concerned about this recovering of Arctic sea ice? Will diminish the cause for AGW? Will this make ice-free Arctic predictions look non-scientific?
Edit: I meant sea ice extent, not volume.
- RioLv 61 decade agoFavourite answer
Isn't that one of the things about GW that keeps changing and readjusting? What is the idyllic state for sea ice? Sorry about answering in the question format, there's still links on the web about 2005, 2012, and now I think its somewhere around 2100. You could tell me almost anything and I couldn't prove you wrong or right.
- Anonymous1 decade ago
Less volume means less extent recovery in future years. Soon all the multi year ice will be gone and the seasonal extent will be a thin shell that shrinks further every year. Very soon the arctic will be ice free in the summer. The predictions will not look un-scientific, they will look conservative. What is the current rate of change of albedo? Could loss of albedo be the positive feedback that has caused the accelerated warming?
- antarcticiceLv 71 decade ago
I think any pretense of you guys being skeptics went out the window long ago, here you don't even seem to be trying to pretend what you have posted is factual. The dotted line (as other have pointed out) is the record low set in 2007, the thick grey line is the average, even the snippet of the total year this graph shows has the extent below the 2007 level for a good deal of the season.
Of course this sort of thing is a double standard for deniers as when the average is on the rise you try to claim it as some sort of recovery and when it is down you try to claim sea ice extent is not an concern.
You of course link to this graph while ignoring the actual information provided by NSIDC on the subject, who looks "non-scientific" here, is as always, painfully obvious.
Try comparing 2010 to 2009 or 2008, if you dare, claims of recovery seem a little silly when 2010 has spent almost the entire period below the 08 and 09 levels.
- VinceLv 71 decade ago
We should still be worried. Even though 2010 is slightly better than 2007, it's still way below average. We can stop worrying when Arctic sea ice extent returns to 1979 levels.
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- Anonymous1 decade ago
Huh... I'm a little bit confused. The blue line is 2010, right? ::reads question again:: And you're saying the graph indicates Arctic sea ice extent is "recovering"... Not melting quite as fast as in 2007 can hardly be considered to be a recovery. Plus, extent isn't really a very good measure of health for the arctic. I'd rather see Volume. It seems to me that extent can be increased while volume is decreased when the ice is breaking up since the 'extent' is considered to be 15% coverage or better. That means 84% open water is still considered in the extent...
- 1 decade ago
It's a good thing there are cartoons available for these types of questions. Just imagine this image is arctic sea ice extent instead of sea level. Principle is the same. http://cambioclimatico.webcindario.com/SeaLevel.jp...
Nope, no need to worry.
- TrevorLv 71 decade ago
I’m assuming that by ‘recover’ you mean that this year the sea-ice extent is the 5th lowest ever known and there’s still three weeks of melting to go. For the time of year it’s the 3rd lowest ever known.
The last date on which there was any recovery was on 22nd March 2010 when sea-ice extent grew by 937km², every day since then it’s retreated (as the graph you linked to shows).
Today’s sea-ice extent is 5,628,438km². Only beaten on this date in 2008 (5,555,156km²) and in 2007 (4,948,428km²).
The summer ice extent this summer (meteorological summer, to date) averages 8,217,203km², only 2007 had a lesser extent with 8,121,401km². Until approx 1960 the sea-ice extent would have been between 10 and 12 million km², since then it has continually declined.
Summary of Arctic Ice Extent 2010
At the start of the year the ice-extent was the 4th lowest on record, it behaved as expected for the first couple of months. During March there was increased recovery of the ice caused by a window of very cold weather settling over the Arctic, this was caused by changes in atmospherics over the North Atlantic and also gave rise to the cold weather and snow felt in parts of the northern hemisphere earlier this year.
By mid April the ice-extent had recovered to it’s greatest area since 2002, but then it began to melt at an unprecedented rate. On 30th April extent was at a record level in recent years, by the end of May it was at the lowest ever for that time of year.
The ice continued to rapidly melt until the end of June, at which point the jet stream stalled. This trapped cold air to the north and hot air to the south, the consequences of which have contributed to the record breaking temperatures and heatwaves to the south of the jet stream and the colder than normal conditions to the north.
Around the same, time the Arctic dipole anomaly returned. This is a new weather event that has only occurred in recent years and is characterised by unusually pronounced differences in air pressure between the air masses over the Canadian and Siberian Arctic. The accompanying winds blew from the south and prevented dispersal of ice into the ocean, where it would ordinarily melt.
With cold air locked over the Arctic and ice prevented from dispersing, the ice-melt decreased, when you look at the first graph (linked below) it’s very clear just when this happened.
It’s now probable that the ice extent will continue to retreat until about 14th September at which point it will be the 3rd lowest on record.
Arctic sea-ice extent in recent years. The solid red line shows extent for 2010, the point where the jet stream stalled and the dipole anomaly kicked in, causing the rate of meting to slow, is the obvious change in the trend from the end of June.
The pecked red line is the slope prior to the stalling of the jet stream and the orange pecked line is the slope after.
Arctic sea-ice extent since 1870 with forward projections based on 6th order polynomials.
Data for both graphs from JAXA / IJIS using AMSR-E satellite data, the same as used by the NSIDC (your source).
- 1 decade ago
You know, when you take one anomaly year and compare it to those after it, it *might* seem like there's an increasing trend, but you and I both know Ottawa that that's not how it works. What more, after the *actual* recovery from that anomaly in 2007 (year 2008), sea ice extent has been falling, so I have no idea where you get this "continues to recover" idea from.
What more still, sea ice volume is also decreasing. In fact, it's lower this year than in 2007. This is the more pertinent figure because it gives the actual amount of ice, instead of the apparent amount of ice.
On a side note unrelated to total arctic sea ice extent/volume, it seems as though the sea ice extent around the Northwest Passage route is quite notably less than in the past few years (and the average, of course):
(It takes a while for the last image to load for some reason, ~20 seconds for me. Not sure if others will have the same problem.)
Edit, response to David:
Have you ever wondered though why Antarctic sea ice is increasing, even though sea surface temperatures are *also* increasing around Antarctica? It's completely useless to merely state that Antarctic sea ice is increasing without giving why and answering this supposed paradox.
Two main reasons exist for increases in Antarctic sea ice: the first is that thinning of the ozone layer causes stratospheric cooling. This cooling strengthens the cyclonic winds around Antarctica and subsequently leads to more formation of polynyas, which leads to more sea ice production.
The second explanation is that increases in surface temperatures lead to increases in precipitation over the Southern Ocean. This precipitation makes the water fresher and stratifies the ocean layers so that the warmer water beneath cannot rise and mix to melt sea ice.
(courtesy of skepticalscience)
- Author UnknownLv 61 decade ago
Where exactly do you see recovery it’s still melting and well below the average and why would this be "worrying"? After all that has happened this summer in Pakistan, British Columbia, Russia, China and Turkey, and after a twelve month temperature record, how on earth would not breaking the ice record be worrying? I would say we should be thankful of something that not everything has been a disaster.
Do you only look at the pretty pictures or do you also read. You will find actual words to read that accompany that image.
- Dana1981Lv 71 decade ago
Wow, only in denier fantasyland could the 2nd-lowest sea ice extent and lowest (by far) Arctic sea ice volume be considered 'recovering'.
Yes, we should be worried, because this declining amount of Arctic sea ice is a significant global warming feedback. And we should be worried that so many people are so divorced from reality that they think this rapid long-term decline is a 'recovery'.Source(s): http://www.ijis.iarc.uaf.edu/en/home/seaice_extent... http://psc.apl.washington.edu/ArcticSeaiceVolume/i...