Arctic Ice Discussion (The Melt)

[4wd]

So much spin goes into the forecasts of catastrophic decline.

Undoubtedly it has diminished in volume and to some extent area, but some of the graphs thrown out seem to bear little relationship to this which is the un-spun version of area.

[BornFromTheVoid]

So much spin goes into the forecasts of catastrophic decline.

Undoubtedly it has diminished in volume and to some extent area, but some of the graphs thrown out seem to bear little relationship to this which is the un-spun version of area.

What "spun" graphs are you referring to?

Edited April 27, 2012 by BornFromTheVoid

[4wd]

Well the Piomass one springs to mind.

[BornFromTheVoid]

I think it was songster that mentioned the projected or extrapolated volume data was all done through blogs and whatnot, rather than it being scientific work.

I find downloading the data and working through it yourself kinda helps with seeing past whatever bias or technique differences you might encounter online.

Seems the extent has just about touched the average line on the NSIDC graph.

[BornFromTheVoid]

Some bad new today then. CT has updated as far as day 117 (April 26th) and the last 2 days have seen drops of over 100,000km2, leaving sea ice area 173,000km2 below average.

Large losses in the Bering sea and sea of Okhotsk have outstripped small gains in the Kara and Greenland seas.

[Gray-Wolf]

sorry for Karyo......back to the melt season it seems? Lets also remember what geographical area Greenland see encompasses and what 'increases' there (down the East coast of Greenland) actually signal. Lets also take not of the distance into the Atlantic this ice travels compared to the Bering sea. I would suggest if we have ice further south than in Bering then it is both older and thicker than the ice in Bering. Let us all hope , both for our 'summers sake' and the old ice along Greenlands North shore and the Canadian Archipelago , that the synoptics shift and the 'Fram Train runs out of steam!

http://www7320.nrlssc.navy.mil/hycomARC/navo/arcticicespddrf_nowcast_anim30d.gif

http://www7320.nrlssc.navy.mil/hycomARC/navo/arcticictn_nowcast_anim30d.gif

[BornFromTheVoid]

sorry for Karyo......back to the melt season it seems? Lets also remember what geographical area Greenland see encompasses and what 'increases' there (down the East coast of Greenland) actually signal. Lets also take not of the distance into the Atlantic this ice travels compared to the Bering sea. I would suggest if we have ice further south than in Bering then it is both older and thicker than the ice in Bering. Let us all hope , both for our 'summers sake' and the old ice along Greenlands North shore and the Canadian Archipelago , that the synoptics shift and the 'Fram Train runs out of steam!

I'm afraid I don't quite agree with the logic in bold. The rate of ice movement south by the East Greenland Current, especially if aided by northerly winds, is more than enough to carry even first year ice as far south as in the Bering sea. Of course, the thicker multi year ice will last longer, but I don't think, given the number of variables, even as a general rule of thumb that we can directly attribute distance south along Greenland to thickness.

[pottyprof]

Some bad new today then. CT has updated as far as day 117 (April 26th) and the last 2 days have seen drops of over 100,000km2, leaving sea ice area 173,000km2 below average.

Large losses in the Bering sea and sea of Okhotsk have outstripped small gains in the Kara and Greenland seas.

Interesting to see that extent is above 1989 levels. Maybe the volume won't compare but it's interesting.

[BornFromTheVoid]

As far as the Arctic sea ice normally goes in March, the extent anomaly pattern couldn't be more different.

[Gray-Wolf]

If it wasn't for the graphics I posted showing the older ice flowing south I'd retract BFTV!

I'd agree about the anoms Pattern though! When you dwell a little though you'll remeber all the talk about our own 'Baltic' extensions over the last couple of years and how this showed 'recovery'

We both know that these extensions will be gone soon enough a the 'anom' pattern will reverse before mid-June when any 'albedo' impact would have been useful?

[BornFromTheVoid]

Using the thickness data to watch the ice move through Fram and beyond is fine, but trying to infer thickness by how south it gets compared to the Bering sea ice doesn't work though imo.

Looks like April is gonna have reverted back to a mean +ve dipole pattern, after a winter of -ve patterns. Not the most encouraging sign but things may still change.

[Gray-Wolf]

I admire your upbeat view of things to come BFTV. I cannot escape the fact that over a poor summer, with more 'old ice' and little transport out of the basin we managed to end up second lowest in our series last year?

I cannot but project similar (soon to be average?) melt levels across the basin but with more (as we are seeing) transport out of the basin. That said we must go into the season looking favourite to take the lowest extent ever recorded this summer? Should we have a warmer summer or transport of ice from the basin be on the high side then there is no way of the extent doing anything other than being the lowest ever recorded come Sept?

We must remember that 07' was 23% lower in extent than anything recorded that far and that it took a 'perfect storm' to accomplish it. Now here we are ,5 years later, with a left trouser leg poor Arctic summer and a pack trapped in the basin posting second lowest on record?

I believe that the Arctic pack was fatally compromised well before 07' (if we'd have taken note of the signs) and that ,as such, an '07' was waiting to happen with the first 'perfect storm synoptic to turn up.

Come the next 'perfect storm' we will inevitably go 'seasonal' that year.

As things are we may well trawl close to 'seasonal' before this occurs merely due to higher basal melting rates and a pack of little structural integrity.

Edited April 30, 2012 by Gray-Wolf

[BornFromTheVoid]

I admire your upbeat view of things to come BFTV. I cannot escape the fact that over a poor summer, with more 'old ice' and little transport out of the basin we managed to end up second lowest in our series last year?

I cannot but project similar (soon to be average?) melt levels across the basin but with more (as we are seeing) transport out of the basin. That said we must go into the season looking favourite to take the lowest extent ever recorded this summer? Should we have a warmer summer or transport of ice from the basin be on the high side then there is no way of the extent doing anything other than being the lowest ever recorded come Sept?

We must remember that 07' was 23% lower in extent than anything recorded that far and that it took a 'perfect storm' to accomplish it. Now here we are ,5 years later, with a left trouser leg poor Arctic summer and a pack trapped in the basin posting second lowest on record?

I believe that the Arctic pack was fatally compromised well before 07' (if we'd have taken note of the signs) and that ,as such, an '07' was waiting to happen with the first 'perfect storm synoptic to turn up.

Come the next 'perfect storm' we will inevitably go 'seasonal' that year.

As things are we may well trawl close to 'seasonal' before this occurs merely due to higher basal melting rates and a pack of little structural integrity.

While none of the years since 07 have had as strong as +ve dipole set up, they have all still been positive and above average in that regard, including last summer. So the ice certainly wasn't held in the Arctic, even last year. If we were to have a -ve pattern this summer, it's possible that the sea ice could hold up quite well. If the consistently +ve summer dipole pattern of the last 5/6 years is a feed back from the melt distribution and associated changes with the ocean-ice-atmosphere interactions, things become a bit more complicated.

I'd agree that the ice was primed for the battering it took in 07 and I think that may have lead to a step change in some aspects of the ice. While the trend remains very much downward, especially since 07, all those years have feature +ve dipole anomaly set ups, so how the ice may cope in it's somewhat "new" state under -ve summer dipole conditions remains to be seen.

[barrel1234]

looks like there will be plenty of ice going through fram with the wind patterns this week, wont be good for ice extent lovers. However long way to go yet until the minimum.

I'm certainly not worried about ice loss or having a seasonal pack, but my personal opinion is that with decreasing solar output over the next solar cycle I am definately worried about possibility of global cooling and the economic effect due to increased fuel being used in the northern hemisphere. The status quo will never continue, never has done in history - there have always been decadal/century fluctuations. There will always be fluctuations and I would prefer less ice rather than more.

[BornFromTheVoid]

Looks like the melt really starting to accelerate now, with the current SIE moving well away from the long term mean

Today we have some quite mild air across the Bering sea, Hudson Bay and still across the sea of Okhotsk

Out to t48, and a ridge extends down from the Arctic into Hudson Bay, introducing colder air into northern parts while mild air holds on in the south. Mild conditions continue across the Bering sea, sea of Okhotsk and now also in the Baffin sea.

To t96, and Hudson Bay remains relatively cool, while a very cold northerly air stream though the Bering strait sends much colder air south across the Bering sea. Meanwhile, the sea of Okhotsk remains very milld, so the SIE could be near 0 there soon. The Baffin sea has much milder air now, so some large losses to be expected here soon, and we also get the first mild incursion along the Siberian coastline, with uppers reaching 0C near the Laptev sea.

By t144, very mild air (with high melt rates) across Hudson Bay, Baffin Sea and Sea of Okhotsk. Milder air is approaching both the East Siberian and Beaufort sea's also. The Bering sea is still quite cool.

The Barents and Kara seas remain quite cool out to t144 though, so melt rate here should be low, but as the ice formed so late, it's hard to tell.

[masheeuk]

The status quo will never continue,

Oh yes they will unless someone breaks their guitars

[barrel1234]

Thanks for taking time to share the charts bftv, Keeps the thread up to date and easy viewing for everyone to see.

[Polar Maritime]

acquired April 25, 2012

acquired April 14, 2012

For the fourth consecutive year, NASA research aircraft are flying over the Arctic to assess the health of the ice in the fast-changing region. Global warming has had a particularly strong impact on the Arctic, yet the effects on the region’s ice have been anything but steady or predictable. Some glaciers are spitting out icebergs and draining the Greenland ice sheet at an alarming pace; others are barely moving; a few are growing thicker.

The flights are part of a six-year mission called IceBridge. The airborne campaign allows scientists to keep an eye on the complex dynamics of the ice, helping them project how much melting ice sheets might elevate sea level and how fast sea ice is likely to retreat. Funded and structured like a satellite mission, IceBridge continues measurements started by the Ice, Cloud, and Land Elevation Satellite (ICESat) in 2003. ICESat stopped collecting data in 2009, making IceBridge critical for ensuring a continuous series of observations until ICESat-2 launches in 2016. IceBridge flights also collect data useful for climate modeling that ICESat could not, including measures of the land topography beneath the ice, grounding line position, and ice and snow thickness.

The top image, captured during an IceBridge flight, shows a glacier in eastern Greenland flowing through a long and narrow valley—a fjord—carved by the movement of ice. Where the edge of the glacier meets the sea, there’s a layer of floating ice dimpled with chunks of icebergs that have broken off from the glacier. Understanding ice mélanges, as these conglomerations are called, is important because there is evidence that they can slow the rate that glaciers like this slip into the sea. The photograph was taken with a camera aboard NASA’s P-3B aircraft on April 25, 2012.

The image below shows a closer view of a different ice mélange; the blue patch in the middle of the image is possibly the result of turbulence from a recent calving event. Because of the disturbance, the ice appears to be thinner and more transparent to the water below. In addition, the underside of ice from glaciers often has a blue color, so it’s not unusual for ice that recently broke off from a glacier to appear this color. This photograph, also taken by the P-3B, was taken on April 14.

This year’s Arctic campaign stands out for completing several more sea ice flights than in previous years and for covering a greater distance. Another highlight: the IceBridge team recently flew a set of coordinated flights with European Space Agency aircraft in order to verify ice thickness measurements made by CryoSat-2.

Throughout the campaign, scientists in the field have been sending back dispatches via the mission’s blog. “The once seemingly insignificant and remote Arctic region is now understood to be intimately connected to the rest of the planet,†noted Goddard Space Flight Center’s Nathan Kurtz in a post published on March 27. “Sea ice variability affecting the severity of snow storms in Europe, melting sea ice increasing the absorption of sunlight by the Earth, and melting ice sheets causing sea level rise are but a few of many such connections.“

• References
  
• Riebeek, H. (2011) IceBridge: Building a Record of Earth's Changing Ice, One Flight at a Time. NASA’s Earth Observatory.
  
• NASA. (2012) IceBridge: Arctic: 2012. Accessed May 2, 2012.
  
• NASA. (2012) Operation IceBridge Blog. Accessed May 2, 2012.
  
• Amundson, J. (2012). Ice Mélange Dynamics and Implications for Terminus Stability, Jakobshavn Isbræ, Greenland Journal of Geophysical Research Earth Surfaces. 001(405).
  

NASA images from the IceBridge Science Team and taken by Jefferson Beck and Maria-José Viñas. Image interpretation by Bob Bindschadler and Sophie Nowicki. Caption by Adam Voiland with reporting from George Hale and Holli Riebeek.

http://earthobservatory.nasa.gov/IOTD/view.php?id=77824&src=twitter-iotd

[Gray-Wolf]

For those still indoubt that GHG's are what done it! ;

http://www.sciencedaily.com/releases/2012/05/120502091932.htm

[jethro]

For those still indoubt that GHG's are what done it! ;

http://www.scienceda...20502091932.htm

I've only briefly scanned the article but first thoughts are why have they used the time period of 1950's - 1970's for the comparison? This was a period of ice expansion in the Arctic, so much so that for a time it sparked concerns of whether or not we were heading into another ice age. IMO, it would have made more sense and made their findings more valid if they had used the period prior to then, the early years of the 20th century when the ice was also declining.

Using the period they have used is akin to picking the high point of 1998 in the global temperature record, then plotting the decline in temperature since, and saying we're cooling.

A bit bonkers really.

[4wd]

I also thought the final paragraph attempting to explain why Antarctic sea ice is growing rather heavy on 'Hence and Thus' and light on real facts.

Edited May 3, 2012 by 4wd

[cheeky_monkey]

the early years of the 20th century when the ice was also declining.

but was it?...and if so it was declining in relation to what exactly?

[jethro]

but was it?...and if so it was declining in relation to what exactly?

Yes it was.

All the info can be found by checking out the peer reviewed studies of Igor Polyakov. He's a well respected scientist, his work is accepted and quoted by the IPCC, he is not, and cannot be claimed to be a sceptic of AGW.

http://www.iarc.uaf.edu/people/igor

An excerpt of this paper http://www2.gi.alaska.edu/~bhatt/publications/polyakov.etal.2003a.pdf

For example, the Arctic temperature was higher in the 1930s–40s than in recent decades, and hence a trend calculated for the period 1920 to the present actually shows cooling.

This was published in 2003, clearly the info from years since then may change the final figures and counter the cooling trend, but the historical facts remain the same.

[BornFromTheVoid]

Before making such judgements on the paper, how about reading first? http://www.agu.org/j...012GL051094.pdf

but was it?...and if so it was declining in relation to what exactly?

There are plenty of papers on older sea ice data, just search it on google.

http://www.geog.mcgi...-no.-1988-8.pdf

http://www.ualberta....Stroeve2007.pdf

[BornFromTheVoid]

NSIDC April Report

http://nsidc.org/arcticseaicenews/2012/05/arctic-sea-ice-reaches-near-average-extent-in-april/

Highest extent since 2001, and just below average.