PIOMAS February 2014 (upgrade to Version 2.1)

Another month has passed, but this time there is more than just a data update. It seems the whole PIOMAS version 2.0 has been upgraded to 2.1. As it says on the Polar Science Center website:

We identified a programming error in a routine that interpolates ice concentration data prior to assimilation. The error only affected data from 2010-2013. These data have been reprocessed and are now available as version 2.1. Ice thickness is generally greater in the Beaufort Chukchi Sea area with the largest differences in thickness during May. Differences in ice volume are up to 11% greater in late spring.

Chris Reynolds has a blog post up on the Dosbat blog that explains the details and what they mean:

[T]he version change impacts overall volume very little. Note that all the following graphs are plotted using the full dataset from 1979 to 2013.

Wipneus has another interesting tidbit on the Arctic Sea Ice Forum:

[A]s a result of the version bump the trends have changed only slightly, especially when taking uncertainty into account. The exponential extrapolation to exactly zero, which was affected most, shifted upward 0.5 years (2016.44 to 2016.94).

With that out of the way we now proceed to the monthly PIOMAS update:

Here is the updated Arctic sea ice volume graph with data up to January 31st:

The gap with the three lowest years 2011, 2012 and 2013 has become considerably smaller in the past month, which probably has to do with relatively warm weather in the Arctic. The difference with 2013, for instance, has gone down from 1859 km3 at the end of the year to 1205 km3 at the end of the January. 2013 started out very low, but crept up a lot towards the end of the freezing season, reflecting a late cold snap that considerably thickened the ice.

This graph produced by Wipneus is a bit clearer:

I'm not sure whether the PIOMAS sea ice volume anomaly graph has also been upgraded to Version 2.1 (it says V2 in the file name), but the trend line is now well above the linear trend, when compared to last month:

With regards to average thickness (crudely calculated by dividing PIOMAS (PI) volume numbers with Cryosphere Today (CT)) nothing much has changed since the previous update:

Here's average thickness for January 31st in metres, with change from last month between brackets:

• 2005: 1.70 (+0.09)
• 2006: 1.69 (+0.16)
• 2007: 1.53 (+0.07)
• 2008: 1.55 (+0.13)
• 2009: 1.58 (+0.11)
• 2010: 1.54 (+0.13)
• 2011: 1.44 (+0.12)
• 2012: 1.48 (+0.18)
• 2013: 1.38 (+0.15)
• 2014: 1.52 (+0.16)

If you want to have a look at the data yourself, you can download the spreadsheet I use and update from GoogleDrive.

The Polar Science Center thickness graph basically shows the same thing:

So, we start the new year with a new version for PIOMAS, but this isn't the only recent news concerning sea ice volume and thickness. Somehow I overlooked it, but in December new CryoSat-2 data have been released, again showing how the cold and cloudy 2013 melting season caused a big bump in sea ice volume (see blog posts by Tamino and DiabloBanquisa for more info).

Updated gridded PIOMAS data have also been released last week, with Chris Reynolds deconstructing and reconstructing the whole thing on Dosbat, and Wipneus producing graphs for the Forum that show the difference with last year:

The difference is clear, especially north of the Canadian Archipelago and Greenland. Still, total volume difference isn't that big, and it will probably get smaller, given last year's cold snap, and relatively warm temperatures in the Arctic at the moment. If volume starts out around the same level of previous years since 2010, it remains to be seen how far last year's rebound stretches.

But that's impossible to predict right now.

Comments

[D_C_S]

I don't normally do curve-fitting, but I gave it a shot with September ASI volumes from (version 2.1 of) PIOMAS.

A problem with using a linear trend for ASI volumes is that incorporating more and more earlier data, including data from prior to 1979 (if it were available), would eventually result in a shallower linear trend that would more poorly reflect the recent linear trend. Incorporating only recent years, starting at some year after 1979, might better reflect the recent linear trend, but it would involve cherry-picking a start point.

To get around this, I looked for the best hyperbolic fit. One branch of a hyperbola (each hyperbola has 2 branches) approaches one asymptote in one direction and approaches another asymptote in another direction. I chose the best fit from among the hyperbola branches that approach a horizontal asymptote towards the left and approach an oblique asymptote towards the right. This best-fit hyperbola branch intersects 0 volume at about year number 2018.21. It intersects year 2014 at volume 3087 km^3, year 2015 at volume 2366 km^3, year 2016 at volume 1637 km^3, year 2017 at volume 900 km^3, and year 2018 at volume 157 km^3 (a whole number year corresponds to September of that year). The horizontal asymptote is at 16742 km^3. (These volumes are to the nearest whole number of km^3.) The slope of the oblique asymptote is about -816.45 km^3 / year, and the oblique asymptote intersects the horizontal asymptote at about year number 1999.61.

I also calculated some best fits with various types of sigmoid curves, allowing the upper and lower horizontal asymptotes to each be at any position for best fit (instead of forcing the lower horizontal asymptote to be at 0 volume). These gave best-fit projections ranging from a continued rapid decline to 0 volume to a stabilization of September volumes near that of September 2013, depending on which type of sigmoid curve was used. So this wasn't very useful to me for guessing when September volume might reach 0.

[Wipneus]

I'm not sure whether the PIOMAS sea ice volume anomaly graph has also been upgraded to Version 2.1 (it says V2 in the file name),

There are two files, named:
BPIOMASIceVolumeAnomalyCurrentV2.1.png
and:
BPIOMASIceVolumeAnomalyCurrentV2.png

but they appear identical in my eyes, and both say:
"Version: IC-SST 2.1"

Comparing with last months version, the downward spikes (I think you know what I mean) are a bit smaller now.

[I Ballantinegray1]

Though too early to make predictions we can look to our climate forecasts for guidance? The odds are looking good for an El Nino to form over summer and recent updates hint toward a possible 'super' Nino event? ( 16 years since the last). The volume losses we saw during the very stunted Nino ( 9 months) of 2010 might hint at how both this and , should we see a full 18 month Nino event, next years losses might trend?
At least we can look to the way this winter differs from last and draw the conclusion that an exact repeat looks unlikely?

[Hubert Bułgajewski]

On google (digital data) you can see it accurately. It was to be expected. Surface ice grows slowly. I think May will come to 0 or 100 km3. And then the cards are dealt again.
http://arcticicesea.blogspot.com/2014/02/arctic-news-u-kresu-mozliwosci.html

[Ned Ward]

The odds are looking good for an El Nino to form over summer and recent updates hint toward a possible 'super' Nino event?

Source?

I usually get my ENSO forecasts from here:

http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf

and as of now, they seem to be saying that close-to-neutral conditions will continue through this coming (NH) summer, with a possible moderate EN beginning in late summer.

Where do you see hints of a "super Nino event"?

[D_C_S]

For September ASI volumes (in km^3) 1979 - 2013 from PIOMAS version 2.1, a hyperbolic fit with a horizontal asymptote to the left (S = 988.02) is better than a linear fit {S = 1456.14), better than a quadratic fit (S = 1003.99), better than a cubic fit (S = 996.78), and better than an exponential fit (S = 1008.93).

"S" is short for "approximate value of SquareRoot((sum of the squares of the differences) / (2013 - 1979 + 1))".

This hyperbolic fit suggests that the first September with virtually no ASI could be in 2019. I'm prepared to switch to a sigmoid curve if a sigmoid trend becomes clear. A sigmoid trend could result in the first September with virtually no ASI being years later than 2019.

[Hubert Bułgajewski]

http://arcticicesea.blogspot.com/2014/02/zasieg-lodu-w-arktyce-pad-historyczny.html
A record in the Arctic. Small ice extent, sea ice second lowest

[Mikerobertsblog.wordpress.com]

Hubert's link seems to show that the Arctic sea ice extent is on the way down. Is it possible that SIE has peaked this early? I use this graphic to track SIE

[jdallen_wa]

Hubert's link seems to show that the Arctic sea ice extent is on the way down. Is it possible that SIE has peaked this early?

Extraordinarily improbable to the point of impossibility. We'd need pretty much continuous flow of heat from the lower latitudes, strong surface winds to force compaction and strong almost continuous SSW events.

That said, if SIE does peak soon, it would be the definition of an extraordinary event.

[Roman Polach]

Maybe the melt season started this year 2 months earlier :)

http://cci-reanalyzer.org/DailySummary/output/T2_anom_satellite1.jpg

Temperature anomally above North pole is very high.

[Ghoshmm]

Anyone know why IARC-JAXA haven't updated data for 2014?

[Ecojosh]

Ghoshmm, they are there, but the link from the graphs page is out of date. This year's data is at: http://www.ijis.iarc.uaf.edu/seaice/extent/plot_v2.csv

[jdallen_wa]

@Roman - the anomalies are indeed astonishing both in scale and persistence, but we don't yet have...

1) the significant increases in energy required to support melt ( i.e. Insolation )

2) Persistent temperatures at or near zero which would balance radiative heat losses, and thus permit bottom melt.

Other factors may also apply.

In short, these present two mechanical, near insurmountable obstacles to melt starting much before the equinox.

[pjmattheis]

For what's worth, I travel back and forth from Kentucky to Alaska throughout the year, and have done from one place or other, since the 70's.

This winter, Barrow has been warmer than KY more than a couple times, and much warmer than its usual. A quick look at AccuWeather temp listings for Barrow since October shows daily highs and lows were above the norm 27/31 days in Oct, 25/30 in Nov, 20/31 in Dec, 24/31 in Jan, and 11/13 so far this month.
While the sun wasn't shining during most of that period, the temps were often well above the 0F limit posted by jdallen_wa.
Finally, the temp is well below 0F today, and trending to stay that way for the next week and more. I've no idea how widespread this anomaly has been across the arctic, but has been a persistent talking point as I've traveled...

I make no claims that I know what this means, or whether it means anything, but there you are.

[NeilBlanchard]

This is looking a little ominous:

http://nsidc.org/data/seaice_index/images/daily_images/N_stddev_timeseries.png

[Apocalypse4Real]

I decided to blog on this point in the season, for sea ice area and extent. The warmth looks set to continue for a couple of weeks.

I added in some sea ice thickness comparison's as well. I am beginning to think that if the warmth of the last couple of years returns to the Beaufort, we will see major melting of the newer multi-year sea ice.

See: http://a4rglobalmethanetracking.blogspot.com/

[Hubert Bułgajewski]

http://arcticicesea.blogspot.com/2014/02/zasieg-lodu-spadek-wciaz-trwa.html
Ice extent in the Arctic - still down.

[Neven]

I am beginning to think that if the warmth of the last couple of years returns to the Beaufort, we will see major melting of the newer multi-year sea ice.

Indeed. Or it could prove to be a defence that prevents the melt from leaving the Beaufort.

Assuming ACNFS is correct, of course. But a very interesting configuration.

[Boa05att]

Climate model projections show an Arctic-wide end-of-century temperature increase of +13° Celsius [23°F!] in late fall and +5° Celsius [9°F] in late spring if the status quo continues and current emissions increase without a mitigation scenario.

http://thinkprogress.org/climate/2014/02/13/3280421/arctic-autumn-staggering-warming/

[Hans Gunnstaddar]

That's a rather substantial deviation in direction from 2013 as seen in the 2nd graph, HB.

[wayne]

I am not a fan of sea ice extent because thinner or thick ice shows up the same. But the lack of extent at this time of the year confirms the effect of a certain cyclonic favoring weather pattern likely at its end.
I elaborate http://eh2r.blogspot.ca/.

What makes a lasting pattern helps create the next one.

[Gerhard Trausner]

Hi all !
At the moment we have thick ice where
in summer it is very likely to disappear (Kara, Hudson, Boufort).
But in the Arctic basin, it is as thin as ever.

[plus.google.com/109791503217924182187]

Well today there is a record low extent according to Cryosphere Today so that heat is certainly taking its toll on the Arctic ice.

[Colorado Bob]

Cat parasite found in western Arctic Beluga deemed infectious

University of British Columbia scientists have found for the first time an infectious form of the cat parasite Toxoplasma gondii in western Arctic Beluga, prompting a call for caution for the Inuit people who eat whale meat.

The same team also discovered a new strain of the parasite, previously sequestered in the icy north, that is responsible for killing 406 grey seals in the north Atlantic in 2012.

Presenting their findings today at the 2014 Annual Meeting of the American Association for the Advancement of Science (AAAS), Michael Grigg and Stephen Raverty from UBC’s Marine Mammal Research Unit say that the “big thaw” occurring in the Arctic is allowing never-before-seen movement of pathogens between the Arctic and the lower latitudes.

“Ice is a major eco-barrier for pathogens,” says Michael Grigg, a molecular parasitologist with the U.S. National Institutes of Health and an adjunct professor at UBC. “What we’re seeing with the big thaw is the liberation of pathogens gaining access to vulnerable new hosts and wreaking havoc.”.

Toxoplasmosis, also known as kitty litter disease, is the leading cause of infectious blindness in humans and can be fatal to fetuses and to people and animals with compromised immune systems.

http://news.ubc.ca/2014/02/13/bigthaw/

[Colorado Bob]

The last 7 days.

http://models.weatherbell.com/climate/ncep_cfsr_noram_t2m_week_anom.png

[Colorado Bob]

Please note the heat surrounding the deep Jet Stream loops.

[John Christensen]

There has been a lot of focus on the NA cold this winter, but it seems like the larger and even more stable Siberian high is the main cause of Arctic warmth this winter.

With the high placed across Northern Siberia, warmer and more humid air is pulled from eastern Scandinavia across the Barentz Sea flows across the ice, as well as causing compacting of the sea ice. The more regular Beaufort high would have pulled Siberian cold dry air across the ice.

Therefore, as always, it is the placement of highs and lows that is shaping the conditions for the ice, and in this case, could result in a very early winter max, unless the high would move towards the NA side of the Arctic..

[Chris Reynolds]

Sorry, pimping my latest blog post:
http://dosbat.blogspot.co.uk/2014/02/uk-wet-summers-post-2007-how-unusual.html

The likelihood of finding that four of the top ten wettest years in the UK lie between 2007 and 2013 by random chance is 0.14%. Therefore it is a virtual certainty (99.8% probability) that the occurrence of 2007, 2008, 2009 and 2012 in the top ten wettest years in the UK is not by chance, but is due to a shift in the processes at play in delivering rainfall to the UK.

This shift occurred in 2007, simultaneous with a new pattern of atmospheric circulation, and the start of a new regime in Arctic sea ice, featuring unusually aggressive sea ice loss, is not an accident. There is a link between exceptional summer UK rainfall, severe UK summer flooding events, and the loss of Arctic sea ice. As I have argued recently, the rate of sea ice loss indicates that the process is more the ice driving the changes, not the atmosphere driving the ice, as 2013 indicates.

Therefore the UK is experiencing cooler wetter summers, likely as a result of sea ice loss. And this has lead to damaging flooding events in 2007, and 2012. This is not happening by chance, it is climate change, ongoing and causing damaging consequences to lives, property and agriculture.

[D_C_S]

Chris:

Using a hypergeometric distribution gives about the same result:

(7! /(4! 3!) (97! / (6! 91!)) / (104! / (10! 94!)) = about 0.001325

I'd rather calculate the probability of four or more (instead of exactly four) of the top ten years being after 2006, which is about 0.001378.

[Chris Reynolds]

Thanks DCS,

I can see where I went wrong with the algebra now, not my strong point. I started programming whilst unsure, and by the time I thought algebra would be fine I'd virtually finished the code.

Then it was just a matter of pressing a button and letting it go while I put my feet up.

[Flakmeister]

Is it my imagination or are we at a record low for Arctic SEI for this date?

http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm

http://nsidc.org/data/seaice_index/images/daily_images/N_stddev_timeseries.png

[jdallen_wa]

Is it my imagination or are we at a record low for Arctic SEI for this date?

Nope, not your imagination. We are in record low territory.

[DavidR]

As of the 15th we appear to have the lowest SIE, lowest SIA and the lowest increase in area since January 1st. The SIE/SIA ratio (1.136) remains high, around the same levels as 2012. looks like another 'interesting' season, coming up.

[NeilBlanchard]

There appears to have been two periods this winter when the ice area actually decreased (melted?). Typical wobbles in the graph are decreased rate of freezing, or even a plateau - but actual decreases before March seems to be (nearly) unique.

[David Sanger]

@NeilBlanchard, actually every year since 2005 has seen strings of 3 or more days of declining sea ice extent in Jan/Feb according to IJIS/JAXA

In 2009 and 2012 the were strings of 5-days drop and in 2006 extent dropped 191K over a 6-day stretch in January

[Neven]

And it's not melting either (too cold for that), but compaction. The relatively high temps could mean that ice isn't thickening as much as it could.

I can't wait for the next PIOMAS update.

[idunno]

This new feature from DMI...

http://ocean.dmi.dk/arctic/ice_temp/index.uk.php

...shows a very interesting pattern of ice temperature. The last 30 days animation shows a huge heatwave at round about the start of this month.

This link may contain flashing images. And select "slow", or yer'll fry yer brain;

[DavidR]

Neven,
The question is how does PIOMAS estimate the volume of ice? If it is based on the height above sea level of a particular flow this will depend on the amount of snow on the flow. The weight of snow varies from 7% to about 50% of the weight of ice. So if the volume shows a lot of snow above the ice flow the estimate of underwater volume will be much higher than it really is. Assuming all the volume above sea level is ice would grossly exaggerate the PIOMAs calculated volume.

[Chris Reynolds]

David,

PIOMAS is a model, not a satellite. The acronym stands for Pan Arctic Ice Ocean Modelling and Assimilation System.

The volume is calculated using grid boxes that cover the region north of 45degN. Each grid box has an effective thickness which is multiplied by the grid box area to give grid box volume. These are then summed to provide overall volume, or as I do, regional breakdowns of volume.

The thickness of snow on top of the ice is not part of the effective thickness.

To calculate the physics involved PIOMAS uses a sub grid box scale thickness distributon. The 'effective thickness' is the thickness to which the sub grid thickness distribution is applied.

[DavidR]

Chris,
I guess what I'm thinking is where will the extra volume come from given that we have had virtually no increase in SIE or SIA over the past three weeks. Is volume not increasing, or is the volume increasing based on snow on top or ice underneath?
Just trying to get a handle on the dynamics of the system.

[Werther]

"Just trying to get a handle on the dynamics of the system" ...
Ha David, an important part of humanity already has a formidable handle on the ice, as a matter of speaking...

[Roman Polach]

What do you think about these red and yellow spots around North pole? Is it typical for this month? It looks like it´s going to melt very early after melt season starts.

http://www.iup.uni-bremen.de:8084/amsr2/arctic_AMSR2_nic.png

[Chris Reynolds]

David,

Nope the snow is not playing a role in the volume of ice, except as an insulator. More snow reduced heat flux through the ice and reduces thickening.

Look at the minima of the last few years, they've been getting lower and lower. With more and more open water at the end of the melt season (of course I'm not including 201 because we haven't yet had the volume maximum for that year).

I can only offer you my best guess as to why peak volume has levelled from 2011 to 2013.

If you look at ice volume of greater and less than 2m thick (in April - month of peak volume):
http://farm3.staticflickr.com/2887/10729912204_8429f2b85a_o.png
You can see that thicker ice has declined (in fact it accounts for most of the volume loss), while ice under 2m thick has increased, but appears to level in 2011 to 2013. I chose 2m thick because ice below 2m thick is generally thermodynamic growth, that over 2m thick is generally mechanically deformed older ice.

I think that what is going on is that the loss of MYI is at an end, further massive losses will only come as the pack transitions to a seasonally sea ice free state. This transition has happened in the peripheral seas (Beaufort to Barents). So the pack has transitioned to a state where most of the volume is from first year ice. The first year ice is readily able to regrow, even from lows such as the 2012 record. Against this idea of MYI reaching a plateau I should note that April ice volume in the Central Arctic region has been declining at a similar rate to previous years post 2007.

This increase in younger ice is due to the thickness/growth feedback. Ice grows at the ice/ocean interface due to heat flux from the ocean to the atmosphere, through the ice. So if ice isn't there (open water) or is thinner than in the past, more open water and thinner ice grows more volume during the freeze season than in the past when thicker ice was present at the end of the melt season.

This negative feedback is predicted in models (including s study using PIOMAS) to put an end to the loss of volume and lead to a 'long tail' as the autumn/winter growth of ice counters summer losses, and the overall volume loss slows to the rate of thinning in winter. This is predicted to lead to longer term persistence of sea ice.

While I think the thickness/growth feedback is underway (it explains the larger seasonal range after the 2007 and 2010 crashes), I doubt it will produce a long tail. This is because despite the levelling of volume over the last few years in winter, summer losses have continued.

2013 does represent an increase in volume, however it was due to weather, both during the summer and notably in May 2013, so doesn't really inform consideration of ice dynamics. what happens to the pulse may however be very helpful when considering ice dynamics. At the end of January 2014 PIOMAS volume was 1.2k km^3 above 2013 at the same time. It is feasible that most of this will be lost next year, if we see ice volume track back to the 23k km^3 average of 2011 to 2013 that will be very informative.

Given the new regional PIOMAS data I now have I could really do with re-visiting my previous posts on when I think the Arctic will be ice free. I might just crack on with that over the next few weeks.

[Chris Reynolds]

David,

Damn, misread your comment - should leave such things till after dinner.

Area/extent at maximum are irrelevant - the situation at the minimum is set by conditions in the Arctic ocean, and extent/area at max are set outside the Arctic Ocean.

[Boa05att]

Warming from Arctic Sea Ice Melting More Dramatic than Thought

Scientists based at the University of California, San Diego have analyzed Arctic satellite data from 1979 to 2011, and have found that average Arctic albedo levels have decreased from 52 percent to 48 percent since 1979 — twice as much as previous studies based on models have suggested, the team reports today (Feb. 17) in the journal Proceedings of the National Academy of Sciences.

The amount of heat generated by this decrease in albedo is equivalent to roughly 25 percent of the average global warming currently occurring due to increased carbon dioxide levels, the team reports.

"Although more work is needed, a possible implication of this is that the amplifying feedback of Arctic sea ice retreat on global warming is larger than has been previously expected," study co-author Ian Eisenman told Live Science.

http://www.livescience.com/43435-arctic-sea-ice-melt-causes-dramatic-warming.html

[Twemoran]

Boa
Interesting article - but the comment section reminded me of why Neven's sires are so wonderful. The deniers there aren't even familiar with the subject - amazing & in need of heavy moderation.
Terry

[Neven]

Neven's sires

I didn't know I had knights who follow me. Makes me want to insert a Holy Grail Youtube vid. ;-)

Nice typo, Terry!

Thanks for the link, Boa.

[Chris Reynolds]

The abstract for the paper is here:
http://www.pnas.org/content/early/2014/02/13/1318201111.abstract

IIRC PNAS publications are paywalled for some time but eventually are free.

A key finding for me: "Changes in cloudiness appear to play a negligible role in observed Arctic darkening, thus reducing the possibility of Arctic cloud albedo feedbacks mitigating future Arctic warming."

[Colorado Bob]

Canada’s Arctic ice caps melting rapidly since 2005, according to documents

Federal data show the Devon ice cap’s northwest sector has lost 1.6 per cent of its mass since the 1960s, the Meighen approximately 11 per cent of its mass and the Melville about 13 per cent, he said. However, approximately 30 to 40 per cent of the ice mass lost has happened since 2005.

“Since 2005 it has enhanced quite significantly,” Burgess said in an interview.
http://o.canada.com/news/national/canadas-arctic-ice-caps-melting-rapidly-since-2005-according-to-documents/

[Colorado Bob]

Increase in Arctic cyclones is linked to climate change

Summary:

Winter in the Arctic is not only cold and dark; it is also storm season when hurricane-like cyclones traverse the northern waters from Iceland to Alaska. These cyclones are characterized by strong localized drops in sea level pressure, and as Arctic-wide decreases in sea level pressure are one of the expected results of climate change, this could increase extreme Arctic cyclone activity, including powerful storms in the spring and fall. A new study uses historical climate model simulations to demonstrate that there has been an Arctic-wide decrease in sea level pressure since the 1800's.
http://www.sciencedaily.com/releases/2014/02/140218100707.htm

[Neven]

What do you think about these red and yellow spots around North pole? Is it typical for this month? It looks like it´s going to melt very early after melt season starts.

Roman, normally I would say: Don't pay too much attention to it, red and yellow spots come and go, but this looks interesting, and it's following that incursion of warm air that's been there for quite a while now.

On the other hand I don't see anything on this ASCAT image for Feb 17 and in Wipneus' animation I posted in this comment.

[Shared Humanity]

What do you think about these red and yellow spots around North pole? Is it typical for this month? It looks like it´s going to melt very early after melt season starts.

http://www.iup.uni-bremen.de:8084/amsr2/arctic_AMSR2_nic.png

I am more amazed by the wide band of lower concentration ice across the CAB. Could this be caused by the persistent high pressures over Greenland and Siberia this winter which have pulled a stream of warm air across the CAB for much of the winter?

What has the CAB looked like at this time in previous years? Have we seen this kind of wide swath of low concentration ice before or is this unusual? If unusual and if we have an average melt season than I think we will see a new record minimum.

[Shared Humanity]

Also, hasn't there been a summer trend of an increasingly persistent Greenland high pressure, influenced by a "cold pole" that forms over the Greenland ice sheet? If so, we could be set for a dramatic melt on the Atlantic side of the CAB. There has already been a consolidation and melt of the ice pack around Svalbard and FJ. Is it possible that this ice will not rebound at all but continue to recede during the remaining small portion of freeze?

[Shared Humanity]

I am also concerned about the large mass of MYI that migrated into the Beaufort last summer. Alaska has had a record warm winter as the persistent Pacific high pressure pulled record warm air over Alaska. Could this warm air streaming into the Beaufort have conditioned this MYI for a strong melt? Despite all of this MYI, the northern coast of Alaska has some evidence of low concentration SIA. If the Beaufort Gyre gets going this summer, how much of this MYI will survive as it moves into the Chukchi? We also should expect the Bering Sea to become ice free very early this year. Could this reduced albedo on the Pacific side make things even worse?

[Chris Reynolds]

Shared Humanity,

I've got a blog post with an animated gif of that movement of old thick ice, it's not unusual, I don't think it's as big as 2010. But I do think it's worth keeping an eye on as part of the collapse of the Beaufort Gyre flywheel. That ice is now entering Chukchi, and will melt out in due course this summer instead of cycling in the gyre and ageing as would have been the case in the past.

[John Christensen]

In anticipation of the next PIOMAS update I wanted to share a brief comparison of volume (km3) by the beginning of each month compared to the same date a year before:

Month Year Volume Difference
Nov. 1 12 -696
Dec. 1 12 -974
Jan. 1 13 -1152
Feb. 1 13 -746
Mar. 1 13 201
Apr. 1 13 -39
May 1 13 -271
Jun. 1 13 825
Jul. 1 13 1.769
Aug. 1 13 991
Sep. 1 13 1.596
Oct. 1 13 1.793
Nov. 1 13 2.086
Dec. 1 13 1.548
Jan. 1 14 1.889
Feb. 1 14 1.252
Mar. 1 14 ?

As you see, Nov. and Dec. '12 did not provide strong ice volume gain, but it turned in January and then more significantly in February with the SSW/cracking event and strong freeze.

After that, March and April '13 did not fare well compared to the year before, but May and June changed the picture dramatically.

Finally, last fall/early winter months were great for Arctic ice build-up, until January, where we dropped about 600 km3 compared to the year before. We are likely to have gotten even closer in February, since we did not have strong cold, so would probably leave us with 100-400 km3 more ice than last year by end of Feb.?

However, we should have the slight upside that last year we had considerably more ice in Okhotsk, Bering, and Barents, which is due for March-early May melting, so might leave us slightly better off than last year by May 1 - ceteris paribus..