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Polar Ice Cap: 5 years left?
Posted: 19 Oct 2010, 10:22
by Cabrone
Here is a 'Hot Topic' article from NZ on the polar ice cap and future trends:
Bottom line: if the relationship between ice volume and extent evident in the NSIDC and PIOMAS data over the last 21 years continues in the near future, then the Arctic will be effectively ice-free in late summer sometime between 2015 and 2020. One interesting observation: the 10 year trend chart above suggests that 2007′s record minimum extent could remain unbroken next year, and the ice would still be on course to disappear within five years. If there’s any upside at all to this message (and I’m struggling to find one) it is perhaps that such a rapid and visible loss of sea ice might finally persuade the international community to take urgent action to reduce the atmospheric carbon load. What a seasonally ice-free Arctic might mean for global climate is something I shall look into a future post.
Article
Graphs
1) Sea ice volume & thickness:
2) Thickness (exploded scale):
3) Forward plots based on data since 1990:
By 2020 September average sea ice extent is reduced to 850,000 km2. The following year (not plotted) it reaches a minimum of 90,000 km2. In other words, if the rate of reduction of ice volume continues at the average rate of the last 21 years, the Arctic will be ice free in summer by 2021.
4) Forward plots based on data since 2000:
If these trends continue, then September ice extent dips below 2 million km2 in 2015, before all but disappearing in 2016.
I look forward to reading his interpretation of 'what a seasonally ice-free Arctic might mean for global climate' will be.
Posted: 20 Oct 2010, 02:27
by kenneal - lagger
I think he's being a conservative scientist here and that we will see an ice free Arctic before 2016, with the proviso that we aren't going into a Maunder Minimum style event. As the ice gets thinner it will be more susceptible to being broken up by wave action and that will make it melt quicker as more surface area is exposed to the warming sea.
If we are going into a cold period, all bets are off and we could, instead, see a revival of ice area. Any revival would be delayed, however, by the thermal inertia of the ocean water so we could see further reductions in ice age and thickness for a few years into a cold period.
Posted: 20 Oct 2010, 09:28
by PS_RalphW
The only proviso I would add is that the plot is estimated average thickness. There is still an area north of Greenland with mostly multi-year ice. That could hang around quiet a lot longer, whilst the rest of the arctic is ice free for a month or more. We will find out soon enough.
Posted: 21 Dec 2010, 08:51
by Cabrone
With the high pressure system sitting over Greenland + further north the ice coverage over the Arctic has been taking a dip.
If this pattern continues then that ice is going to be in even poorer state than usual come the melt season.
5 years and counting.......
NSIDC
Posted: 21 Dec 2010, 11:38
by biffvernon
Cabrone wrote:
If this pattern continues then that ice is going to be
all gone by about June 2011. Of course the pattern of the last few days won't continue - that would be silly
But that little dip we see at the end of the graph is rather unusual, like the weather we've been having in the British Isles.
Posted: 21 Dec 2010, 14:16
by Cabrone
biffvernon wrote:Cabrone wrote:
If this pattern continues then that ice is going to be
all gone by about June 2011. Of course the pattern of the last few days won't continue - that would be silly
But that little dip we see at the end of the graph is rather unusual, like the weather we've been having in the British Isles.
With that dip the sea ice extent has actually gone down recently...........and we are in the middle of winter.
Posted: 21 Dec 2010, 14:28
by biffvernon
(Psst...It's all to do with which way the wind blows but don't tell the flat-earthers.)
Posted: 21 Dec 2010, 17:10
by phobos
Well lets look at the positives, at least it will be less dangerous when they are drilling for oil.....
Posted: 21 Dec 2010, 18:46
by biffvernon
Posted: 24 Jan 2011, 11:53
by PS_RalphW
The arctic sea ice looks to be heading for the lowest winter extent by quite some margin this year. Still possible for a late freeze, but the weather looks set for a few weeks at least.
http://nsidc.org/arcticseaicenews/index.html
The biggest non-freeze is off the North East cost of Canada. The low extent will mean a fast melt in the early part of the summer, as the ice will be thinner than usual near the edges. That will reduce albido, and increase water temperatures.
Posted: 24 Jan 2011, 15:50
by RenewableCandy
...and possibly b***er up the Gulf Stream and leave the good ol' UK even colder than it's been of late? (runs off to buy more Russian thermals...)
Posted: 24 Jan 2011, 16:01
by Pepperman
I find this chart very interesting (and more than a little worrying):
http://nsidc.org/arcticseaicenews/2010/100410.html
ETA: hmm something went very wrong when I tried to embed this url:
http://nsidc.org/images/arcticseaicenew ... igure6.jpg
It's a forum breaking 4538 x 6096 pixel jpg
Posted: 24 Jan 2011, 16:03
by DominicJ
Maybe someone should tell the Russians?
They're convinced several ships have been stuck for over a month, some days the ice expanding faster than they can sail, although to be fair, with ice hitting the sea bottom, that wasnt very fast...
Posted: 24 Jan 2011, 16:17
by PS_RalphW
So some captains got cocky and miss-judged the localised sudden refreeze. Once they were stuck they were always going to stay stuck. The more they were delayed by ice, the more the thickening ice was going to delay them.
Weather has been more volatile of late...
Posted: 24 Jan 2011, 16:23
by kenneal - lagger
DominicJ wrote:They're convinced several ships have been stuck for over a month, some days the ice expanding faster than they can sail,
It's January, Dom. Ice is supposed to be expanding rapidly all over the Arctic at this time of year. This year, however, it's only expanding rapidly in a some areas and it's a bit late as well.
