The 2016/2017 freezing season

[Peter Ellis]

FOW do you have a link to the 94 m salinity maps of previous years?

This is HYCOM's salinity animation for the last year.  I'm really not seeing anything different about the start of 2017 compared to 2016.
https://www7320.nrlssc.navy.mil/hycomARC/navo/arcticsss_nowcast_anim365d.gif

[pccp82]

I hope this is apples to apples, but compared to 2012, the magnitude of the area that is below average thickness for this time of year is staggering.

eyeballing, there could be 2 million sq km that are 1 meter below 2012 thickness according to HYCOM.

[elioe]

Hello, I'm a newcomer. Hopefully this is the correct thread to post the following.

Freezing Degree Days north of 80N have broken low records by extraordinarily large margin this freezing season. While the ice volume according to PIOMAS is record low, the margin is not that extraordinary. I haven't looked at any tabular data, just from these two graphs:

http://psc.apl.uw.edu/wordpress/wp-content/uploads/schweiger/ice_volume/BPIOMASIceVolumeAnomalyCurrentV2.1_CY.png
http://4.bp.blogspot.com/-qDBudaFi7CU/WIrFS1xO1dI/AAAAAAAAARc/vvxOPIit5w0Hj5r7j1xpJxKPpdRgzWCTACLcB/s1600/Total%2BFDDs_1_26_2017.png

From those, I made this crude graph. Blue lines for the freezing seasons 2010-11 to 2015-16, red line for this season until December, and the red circle for the position, near which January figures are likely to be.



The relationship between FDD and ice growth this winter is much different from previous six seasons. Is a greater percentage of ice growth occurring south of 80N, or is the heat transfer coefficient north of 80N extraordinarily high? If latter, why? I don't see how the general decrease in thickness could have increased the coefficient so much. A more uneven distribution of ice thickness? More fractures in the ice, exposing more open water?

And if the heat flux from ocean is enhanced by such factors, how big is the role of this enhancement in maintaining those extraordinarily high temperatures?

Thanks in advance.

[S.Pansa]

Re Salinity.
Narrowing the palette somewhat some differences can be recognized (if you open the pics in seperate tabs). Don't know if this is significant though.

[Tigertown]

The quantity of both thick and less thick ice leaving via the Fram is starting to make a huge area of low concentration in the heart of the CAB, including the NP area, much the same way export through the Bering Strait did to the ESS and Beaufort. I am scared that volume numbers are worse than we think at this point, not mention the near future. Export alone appears to be outpacing the Arctic's current ability to create new ice, and that's not even allowing for ice loss through other means. That's my impression. See for yourself; zoom in, click a date like the 1st, and click the animate button.

www.polarview.aq/sic/arctic/

[gregcharles]

Apples compared with, not oranges but rocks.

The whole area within the Arctic circle gets heated 24/7 when in sunshine.
The whole area within the Antarctic circle at the same time gets zero heat.
The equatorial belt gets 12 hours heating and 12 hours cooling.

The figure of 8,000,000 sq. km must be compared with the rest of the daylit planet, not the whole planet.  Also, the Arctic buildup of 24 hour heat versus the heating-cooling cycles elsewhere must be factored in.

Correct me if I'm wrong, but I think that only the poles flip from continuous sunshine to continuous darkness. Half of the arctic circle is already getting partial daylight now, though we're six (seven?) weeks away from the equinox. Your points are good though, just maybe a bit stronger than you thought.

[DrTskoul]

Re Salinity.
Narrowing the palette somewhat some differences can be recognized (if you open the pics in seperate tabs). Don't know if this is significant though.

Kara sea is toast....

[Jim Williams]

Freezing Degree Days north of 80N have broken low records by extraordinarily large margin this freezing season. While the ice volume according to PIOMAS is record low, the margin is not that extraordinary. I haven't looked at any tabular data, just from these two graphs:

Some people here have discussed ice growth at length, and basically...the thicker the ice the slower it grows.  Therefore it would not be surprising for the  FDD to be more anomalous than the Volume.

[jai mitchell]

Model are currently showing an extreme arctic warming event from both the Atlantic and Pacific sides for Feb 3rd.  In this image it shows nearly 1/2 of the cab at ~(negative)4C surface temperatures.

edit, sorry it was -4C not +4C avg temps.  just saw that.

[Pragma]

Apples compared with, not oranges but rocks.

The whole area within the Arctic circle gets heated 24/7 when in sunshine.
The whole area within the Antarctic circle at the same time gets zero heat.
The equatorial belt gets 12 hours heating and 12 hours cooling.

The figure of 8,000,000 sq. km must be compared with the rest of the daylit planet, not the whole planet.  Also, the Arctic buildup of 24 hour heat versus the heating-cooling cycles elsewhere must be factored in.

Correct me if I'm wrong, but I think that only the poles flip from continuous sunshine to continuous darkness. Half of the arctic circle is already getting partial daylight now, though we're six (seven?) weeks away from the equinox. Your points are good though, just maybe a bit stronger than you thought.

I agree, and while the initial insolation is minimal, it is all about energy balance. It may not cause melting, but it will retard or stop further freezing.

I thought the original assessment that the change was trivial was quite cavalier and as someone already pointed out, the system *was* in equilibrium, so saying the changes expected are minimal is akin to the denier argument that CO2 is such a small percentage of the atmosphere that it can't possibly have an effect.

I am well aware that the system is complex but a back of the envelope calculation says that we lose about 18 Km3 of ice per year which requires about 600 petajoules of energy. As we have progressively less ice to melt, that energy is going to heat up other things. This 600 pj of energy was just a small amount of what was available, if we assume an albedo of ~.9, so this now excess energy combined with the albedo flip, IMHO, can only result in rapid heating of the open water and the permafrost.

I realize the this is only a first order stab at the situation, but it's enough to make me worry about the very near future.

[Tigertown]

We have got to remember, we have already lost much of the Arctic's ability to cool the Earth. Whatever the reasons, extra moisture, cloud cover, GHG's, the heat is mostly staying there. Before, when it was carried by currents and so forth to the Arctic, it was shed during the long night. Not so much, now. So, when we consider what will happen when there is no sea ice, and the albedo loss and insolation gain, those numbers have to be combined with the change in retention numbers to get the real effect.

[NeilT]

And viddaloo was banned because he was an asshole, creating conflicts everywhere, not because he had a simplistic statistical extrapolation without any physical basis. So please, don't use him as an example or call him friv. Friv made great contributions with a sense of humour, and had no problems whatsoever with being wrong about something. I hope to see him back again.

My very sincere apologies for mixing Friv up with viddallo.  It was a mistake of time and focus.  Nothing else.

No more concern trolling, no more gloating. Thanks.

It was absolutely _not_ gloating, I've made a mess of predictions more times than I care to think about in the last 20 years, so there is absolutely nothing to gloat about.

I would consider a post on my reasons for mentioning it but not on this thread as it's now totally OT and, honestly, I doubt it's worth the effort and I have a lot of pressing things I need to get done over the next month.

[Neven]

I don't mind the gloating so much (I do it myself too, on those sparse occasions I turn out to be right), but rather the gloating in combination with the 'nobody listened to me and laughed at me'.

I'm not saying you do exactly that, and I realize this was your first exposure to Feeltheburn's concern trolling.

[NeilT]

We have got to remember, we have already lost much of the Arctic's ability to cool the Earth. Whatever the reasons, extra moisture, cloud cover, GHG's, the heat is mostly staying there. Before, when it was carried by currents and so forth to the Arctic, it was shed during the long night. Not so much, now. So, when we consider what will happen when there is no sea ice, and the albedo loss and insolation gain, those numbers have to be combined with the change in retention numbers to get the real effect.

Let me put that another way.  If we have another melting season the same as 2007, in 2017, it will be in the context of an arctic which is post the 2007 and 2012 step changes in ice mass balance and albedo effect.

Something like this.

[georged]

We're about 55 days from the point at which 75N receives a quantifiable amount of energy (greater than 1kw/M^2).

The difference between bare ice and open water, is an albedo of ~.5-.7 and an albedo of 0.06.

The energy balance of the Arctic is going to be somewhat different this spring.

See:
http://forum.arctic-sea-ice.net/index.php?topic=1543.0

[NeilT]

I don't mind the gloating so much (I do it myself too, on those sparse occasions I turn out to be right), but rather the gloating in combination with the 'nobody listened to me and laughed at me'.

I'm not saying you do exactly that, and I realize this was your first exposure to Feeltheburn's concern trolling.

Actually Neven it wasn't even to do with "nobody listened to me and laughed at me". I've been laughed at, on and off, for 20 years because I followed Global Warming then Climate Change.  I've been laughed at by professionals.

No, it was the "If you have an opinion like that you shouldn't be allowed to be commenting here" responses which really irked and that was balanced a lot by the kind people who supported the right to "have an opinion".  That attitude is something I never heard on here a while back; but it is something which is cropping up more.

As for FTB, thanks I will be more careful.  But, I have on at least one occasion been accused of potential concern trolling.  Me; who thinks that were totally screwed and that at least 2 Billion people, up to 7 Billion people, are going to be killed by AGW.

Go figure....

[subgeometer]

Those cracks above  FJL remind me of how a perished fabric frays along the grain when tension is applied across it. The furthest north on ATeam's animation is a long way into the pack, which appears to have the strength of wet toilet paper.

DMI 80 North temperatures haven't fallen below about 247 Kelvin for over a year now , ie 5 above the old average. Is it ever likely to do so again? The open water even in winter where all was ice before must play a part.

The area around Svalbard hasn't frozen at all despite the FDDs, because of the warmth of the advancing current there. With the warm salty water also under the Arctic, which already seems to have been stirred a little, I'm worried that a winter blue ocean follows fast on the heels of a summer meltout, in just a few years

[subgeometer]

Model are currently showing an extreme arctic warming event from both the Atlantic and Pacific sides for Feb 3rd.  In this image it shows nearly 1/2 of the cab at ~(negative)4C surface temperatures.

edit, sorry it was -4C not +4C avg temps.  just saw that.

GFS is showing above freezing temps in parts of the ESS on Feb 2 . The heat comes with a firehose of moisture, over 10kg/m2, carrying its own latent heat. Later in the run another big pulse comes in over Svalbard.

And the weird donut in the geopotential map persists centred on the Bering Strait and Chukchi Sea for days

http://cci-reanalyzer.org/wx/fcst/#GFS-025deg.ARC-LEA.GPH500-MSLP

[Tor Bejnar]

Hello, I'm a newcomer. Hopefully this is the correct thread to post the following.

Freezing Degree Days north of 80N have broken low records by extraordinarily large margin this freezing season. While the ice volume according to PIOMAS is record low, the margin is not that extraordinary. I haven't looked at any tabular data, just from these two graphs:

http://psc.apl.uw.edu/wordpress/wp-content/uploads/schweiger/ice_volume/BPIOMASIceVolumeAnomalyCurrentV2.1_CY.png
http://4.bp.blogspot.com/-qDBudaFi7CU/WIrFS1xO1dI/AAAAAAAAARc/vvxOPIit5w0Hj5r7j1xpJxKPpdRgzWCTACLcB/s1600/Total%2BFDDs_1_26_2017.png

From those, I made this crude graph. Blue lines for the freezing seasons 2010-11 to 2015-16, red line for this season until December, and the red circle for the position, near which January figures are likely to be.



The relationship between FDD and ice growth this winter is much different from previous six seasons. Is a greater percentage of ice growth occurring south of 80N, or is the heat transfer coefficient north of 80N extraordinarily high? If latter, why? I don't see how the general decrease in thickness could have increased the coefficient so much. A more uneven distribution of ice thickness? More fractures in the ice, exposing more open water?

And if the heat flux from ocean is enhanced by such factors, how big is the role of this enhancement in maintaining those extraordinarily high temperatures?

Thanks in advance.

Welcome to Neven's forum, elioe!

I think the FDDs (or lack thereof) affects thickness/volume more than area/extent.  Calm sea water and approximately -10^o air temperature will freeze the ocean surface, but such 'warm' air temperatures will not thicken the ice very much over the winter. Others know something (and I know virtually nothing) about the formulas associated with ice thickening and air temperature.  They may be the ones to really answer your questions.

[logicmanPatrick]

Apples compared with, not oranges but rocks.

The whole area within the Arctic circle gets heated 24/7 when in sunshine.
The whole area within the Antarctic circle at the same time gets zero heat.
The equatorial belt gets 12 hours heating and 12 hours cooling.

The figure of 8,000,000 sq. km must be compared with the rest of the daylit planet, not the whole planet.  Also, the Arctic buildup of 24 hour heat versus the heating-cooling cycles elsewhere must be factored in.

Correct me if I'm wrong, but I think that only the poles flip from continuous sunshine to continuous darkness. Half of the arctic circle is already getting partial daylight now, though we're six (seven?) weeks away from the equinox. Your points are good though, just maybe a bit stronger than you thought.

I could have put it better, yes.

oren cites Martin Gisser as stating:"The fraction of solar input impinging on the Arctic is very small compared to the whole earth. The area of Arctic ice is, depending on the season, as much as 8,000,000 square kilometers, and the area of the earth is 510,000,000, so even if the Arctic got its fair share and it went from white to black year round that would cap its contribution at less than 1.5%;"

In my comment above I should have stated that area shoiuld not be compared with area.

When dealing with loss of ice and snow cover, the correct comparison is between sums of A x a - Area x albedo.  First select a scale, say 100km grid.  Now, for each grid in the Arctic plot the albedo.  For each grid not in the Arctic do the same.  The ratio between the two is a true measure of the Arctic's performance as the Earth's cooler.  The figure I get is circa 8.8%.

Bear in mind that albedo can refer to light or heat.  During the night the albedo is measured with respect to infra red.  It is a mistake to assume that albedo is not a factor in darkness.

A final note on global albedo change, as of December 31 2011:

Taken across the planet, no significant global trend appears. As noted in the anomaly plot below, global albedo rose and fell in different years, but did not necessarily head in either direction for long.
...
In the maps at the top of the page, however, some regional patterns emerge. At the North Pole, reflectivity decreased markedly, a result of the declining sea ice on the Arctic Ocean and increasing dust and soot on top of the ice. Around the South Pole, reflectivity is down around West Antarctica and up slightly in parts of East Antarctica, but there is no net gain or loss. At the same time, Antarctic sea ice there has been increasing slightly each year.

source: NASA Earth Observatory

hth.

[subgeometer]

Hello, I'm a newcomer. Hopefully this is the correct thread to post the following.

Freezing Degree Days north of 80N have broken low records by extraordinarily large margin this freezing season. While the ice volume according to PIOMAS is record low, the margin is not that extraordinary. I haven't looked at any tabular data, just from these two graphs:

http://psc.apl.uw.edu/wordpress/wp-content/uploads/schweiger/ice_volume/BPIOMASIceVolumeAnomalyCurrentV2.1_CY.png
http://4.bp.blogspot.com/-qDBudaFi7CU/WIrFS1xO1dI/AAAAAAAAARc/vvxOPIit5w0Hj5r7j1xpJxKPpdRgzWCTACLcB/s1600/Total%2BFDDs_1_26_2017.png

From those, I made this crude graph. Blue lines for the freezing seasons 2010-11 to 2015-16, red line for this season until December, and the red circle for the position, near which January figures are likely to be.



The relationship between FDD and ice growth this winter is much different from previous six seasons. Is a greater percentage of ice growth occurring south of 80N, or is the heat transfer coefficient north of 80N extraordinarily high? If latter, why? I don't see how the general decrease in thickness could have increased the coefficient so much. A more uneven distribution of ice thickness? More fractures in the ice, exposing more open water?

And if the heat flux from ocean is enhanced by such factors, how big is the role of this enhancement in maintaining those extraordinarily high temperatures?

Thanks in advance.

Welcome to Neven's forum, elioe!

I think the FDDs (or lack thereof) affects thickness/volume more than area/extent.  Calm sea water and approximately -10^o air temperature will freeze the ocean surface, but such 'warm' air temperatures will not thicken the ice very much over the winter. Others know something (and I know virtually nothing) about the formulas associated with ice thickening and air temperature.  They may be the ones to really answer your questions.

Given the newly open water on Atlantic side, has the temp anomaly above 80 North been greater than deeper in the basin? From memory it seems that way. That could explain the greater volume growth per FDD. There was a arctic basin temp chart on the google arctic sea ice graphs page but it has been displaced or removed

[6roucho]

As for FTB, thanks I will be more careful.  But, I have on at least one occasion been accused of potential concern trolling.  Me; who thinks that were totally screwed and that at least 2 Billion people, up to 7 Billion people, are going to be killed by AGW.

REG: Listen. If you wanted to join the People's Front of Judea, you'd have to really hate the Romans.
BRIAN: I do!
REG: Oh, yeah? How much?
BRIAN: A lot!
REG: Right. You're in. Listen. The only people we hate more than the Romans are the Judean People's Front.
CROWD: Yeah...
JUDITH: Splitters.

[Peter Ellis]

The relationship between FDD and ice growth this winter is much different from previous six seasons. Is a greater percentage of ice growth occurring south of 80N...

What you're missing here is the time dimension. 

If you look at this graph, you'll see that in previous years we hit 1500 FDD in ~mid November.  This year it took until January, with the ice edge being correspondingly further South.  So we have fewer FDDs, but the FDDs we do get are being used more efficiently - because we're still getting a thin skin forming (when each FDD contributes significantly to ice growth), but not so much thickening (when each FDD contributes less to ice growth).

[Jim Hunt]

Warm Atlantic water is penetrating closer to the pole in the top 300 meters.

If you haven't seen it already you may find this interesting:

Winter ocean-ice interactions under thin sea ice observed by IAOOS platforms during N-ICE2015: Salty surface mixed layer and active basal melt

Here we focus on mid-winter conditions as documented by IAOOS (Ice Atmosphere Arctic Ocean Observing System) platforms deployed during Floe 1 of N-ICE2015 in January–February 2015 in the middle of the polar night. These platforms carry an ice mass balance instrument monitoring temperature across the air/snow/ice/ocean interface and an ocean profiler measuring conductivity hence salinity, temperature and dissolved oxygen concentration down to 500 m or more. We use the IAOOS platform data to examine the winter hydrography in the region and the ocean processes responsible for the winter basal
sea-ice melt over the Svalbard continental slope.

Over the Svalbard continental slope, the warm AW from the Svalbard Branch was only 20–40 m from the sea surface. Profiler observations documented an ~70 km AW extension offshore the 500 m isobath and an offshore deepening of the AW over the continental slope.

The thin and warm mixed layer above the Svalbard continental slope resulted in significant sea-ice melt in the middle of winter. The warming of the under-ice ocean is clearly visible in the SIMBA data. Near-inertial fluctuations in the under-ice temperature records suggest that near-inertial gravity waves bring heat from the shallow AW inflow up to the surface.

[NeilT]

JUDITH: Splitters.

 

[romett1]

I agree with Tigertown, Fram export remains strong, compared todays image vs yesterday, 26 hours difference. Waiting also January volume numbers.
Photos from https://weather.gc.ca/data/satellite/hrpt_dfo_ir_100.jpg

[Tigertown]

I just don't feel confident in much other than PIOMAS. Looking forward to the update.

[elioe]

The relationship between FDD and ice growth this winter is much different from previous six seasons. Is a greater percentage of ice growth occurring south of 80N...

What you're missing here is the time dimension. 

If you look at this graph, you'll see that in previous years we hit 1500 FDD in ~mid November.  This year it took until January, with the ice edge being correspondingly further South.  So we have fewer FDDs, but the FDDs we do get are being used more efficiently - because we're still getting a thin skin forming (when each FDD contributes significantly to ice growth), but not so much thickening (when each FDD contributes less to ice growth).

Which graph? And isn't 1500 FDD normally in Mid-December?

AFAIK, at least 2007-08 and 2012-13 had greater ice extent increases between September and January. The thickening of old ice must be smaller, when FDD is smaller, since thermal conductivity remains the same. But I don't see, how new ice formation at the edges could explain the difference this year in the FDD-volume relation.

I was thinking like this: Cyclone comes in, and cracks appear within the old thick ice. New ice forms in those cracks. Then winds shift, pushing old ice back together, and the new ice gets compressed into piles of rubble. Then a new cyclone comes in, opens new cracks, and so forth.

And that this process would be new, or greatly enhanced compared to previous years. But I can't alone verify or overturn my assumption. It would be nice to look at raw PIOMAS data, to be able to look only the thickness values within the perennial ice cover. But me no speak 32-bit.

[FishOutofWater]

Thanks, Jim. I hadn't seen that report. What's interesting and relevant to the ice melt waves we are seeing now is the conclusion that gravity waves may be pronounced near the ice edge. These waves cause heat to be mixed upwards from the Atlantic water layer or from any warm layer, such as the summer water layer, above the Atlantic layer. Quoted text from article in teal.

The under-ice temperature, slightly above freezing over the deep slope of the Yermak Plateau, did not generate significant melt. In contrast, the thin and warm mixed layer above the Svalbard continental slope resulted in significant sea-ice melt in the middle of winter (Figure 10). The warming of the under-ice ocean is clearly visible in the SIMBA data. Near-inertial fluctuations in the under-ice temperature records suggest that near-inertial gravity waves bring heat from the shallow AW inflow up to the surface. However, the deep expression of the near-inertial signal could not be examined with the 12 h sampling of the IAOOS profiler during N-ICE2015. A higher sampling rate should be used in the future to enable studies like those by Dosser et al. [2014] or Dosser and Rainville [2016]. Nearinertial waves in the upper ocean formed over the Svalbard Branch could be caused by several mechanisms: tides interacting with topography, storms and mesoscale features. The largest near-inertial signal was observed close to the ice edge (Figure 10), in less packed ice, as the wind could directly force the ocean. In the changing Arctic, with more ice-free area and leads [Willmes and Heinemann, 2016], an increase in nearinertial waves is expected [Dosser and Rainville, 2016] potentially bringing heat up to the surface and promoting sea-ice melt.

In situ observations of large sea-ice basal melt (more than 71 cm in less than 2 months) over the Svalbard
continental slope caused by heat coming from the Atlantic Water confirmed previous influences from theoretical
considerations and indirect data [e.g., Rudels et al., 1996; Ivanov et al., 2016]. Large ocean-to-ice heat
flux is a main process responsible for the sea-ice melt in winter north of Svalbard.

[A-Team]

Waiting January volume numbers.

Piomas daily volumes for Jan 17 are a good two weeks off. Recent posts have looked at the observational hybrid CryoSMOS which still has nothing posted for 2017; otherwise the comparison to Jan-Feb 2016 is ready to go.

Below, the animation compares 14 days of DMI CICE thickness to Hycom out to Jan 29. Thickness readily converts to volume though these products do not take that step.

The four thickness/volume products we use differ wildly. However they all get certain things right (like ice edge and ice pack motion) because the products 'check in' from time to time with satellite imagery (ie, recolor it). Which is better, or does that vary seasonally, are inter-year comparisons informative? Did Piomas ever get its boat back afloat after nearly capsizing on a Dec excursion?

32 bit

Are you thinking of 16-bit Sentinel and Landsat-8 pictures? Not how these other products work. Usually the sites provide a netCDF file, .nc which is just a bundle of excel tables from which you can do calcs and make maps using govt freeware called Pandora which switches seamlessly to whatever numerical format you want. For example:

http://data.meereisportal.de/data/cs2smos/version3.0/n/2016/cs2_smos_ice_thickness_20160208_20160214.nc

[Jim Hunt]

Which graph? And isn't 1500 FDD normally in Mid-December?

It is in recent years if you're using DMI's T2 >80N data. Perhaps Peter is thinking of a different graph?

[Tigertown]

So, at the end of Jan. 2016 we were at 18,536 km3 per PIOMAS. Obviously by comparison, we are not even close to that as this month closes out. We have the chart made by Wipneus for JAXA volume. I have all the confidence in the world in Wipneus, but how accurate is JAXA on thickness? And how accurate does that make the graph?

[meddoc]

So, at the end of Jan. 2016 we were at 18,536 km³ per PIOMAS. Obviously by comparison, we are not even close to that as this month closes out. We have the chart made by Wipneus for JAXA volume. I have all the confidence in the world in Wipneus, but how accurate is JAXA on thickness? And how accurate does that make the graph?

If this is correct, brace for Impact.
Global Nuclear War this Spring/ Summer & all kinds of Chaos.

[magnamentis]

So, at the end of Jan. 2016 we were at 18,536 km³ per PIOMAS. Obviously by comparison, we are not even close to that as this month closes out. We have the chart made by Wipneus for JAXA volume. I have all the confidence in the world in Wipneus, but how accurate is JAXA on thickness? And how accurate does that make the graph?

just a thought, might be off or irrelevant but interested in opinions:

does it really matter what the absolute numbers really are? i mean, as long as we always compare the same source with previous data, sources that cover the longest possible time frame following the same algorithm, including the same errors and shortcomings, we can very well draw the picture as to how things develop, even without knowing the absolutely correct values.

really, i'm just asking because as a non-scientist in that field that's how i would try to get the most out of what's there, while if we (they) would year after year improve the algorithm to get better accuracy i think that the non-consistent nature of that approach would leave us all with less instead of with more valuable information. ?

just discard it if that's totally of a thought :-)

[Neven]

That's always been my perspective when comparing years, MM. Even if I don't deem the data reliable (for instance ACNFS or HYCOM), it's still interesting to compare with previous years.

[Pragma]

You are correct to a certain extent. What most analysis tries to do is extract trends or relationships, so relative values are useful, even though they are not absolute. That said, trying to tease out information when the signal is highly variable is a real challenge. The wide swings can be caused by natural variability (chaos), a separate independent influence or simply noise inherent in the system.

As you say, looking at a series of successive measurements are useful for removing noise so that smaller, lower frequency components can be seen, but you still have to consider the measurement method itself. If the measurements all have a constant offset, then a trend can be obtained, but you could be way off with respect to the y axis. i.e. an estimate of when we will hit zero.

Secondly, is the issue of linearity. JAXA may be very good at estimating ice thickness when it is half a meter or more, but may over or underestimate the thickness when it is, say, 20 cm or less.
This would mean that as the overall ice thickness drops, the two volume measurements must be compared with caution.

Algorithms are regularly checked against other methods or proxies as a sanity check, but every measurement system has an inherent band of uncertainty and/or error. That's just life.

I don't know enough to comment on JAXA so I'm not suggesting it is producing poor data. I'm just talking about the challenges and pitfalls of data acquisition and analysis.   

[elioe]

I mean the data here:

http://psc.apl.uw.edu/research/projects/arctic-sea-ice-volume-anomaly/data/model_grid

Monthly mean thickness 1979-2013 is available as text files, and those I can convert easily to matrices to be run on GNU Octave. Why can't newer data also be available as such?

And thanks, I'll try to learn how to read such .nc -files.

[BornFromTheVoid]

The 5 day average NSIDC extent is back to losses, and lowest on record too.

Interestingly, from 1979-2002, no year had more than 3 drops in the 5 day average in January. Since then we've had 2003 (5), 2006 (6), 2007 (4), 2009 (4), 2012 (5) and so far this year we've had 5 also.

Another interesting stat is in each of the years with more than 3 drops, all drops were grouped together/consecutive. For example, the 2003 losses were from the 22nd to the 26th inclusive, 2006 from the 16th to the 21st, 2012 from the 16th to the 20th, etc
This year, they've been broken apart, dated 9th, 10th, 13th, 16th and 29th so far

I have some ideas on why that might be, but I'll leave the speculation to you folks!

[Neven]

I have all the confidence in the world in Wipneus, but how accurate is JAXA on thickness? And how accurate does that make the graph?

I believe there is very little info on how the model works exactly, no peer-reviewed paper or some such.

I have some ideas on why that might be, but I'll leave the speculation to you folks!

I'm not reall keeping a close eye, but to me it would seem that we see a similarity arising between Arctic and Antarctic sea ice: volatility. Mainly at the edges, of course. That's because the ice is thin and doesn't get a chance to thicken because of heat/moisture via atmosphere and ocean.

[BornFromTheVoid]

I'm not reall keeping a close eye, but to me it would seem that we see a similarity arising between Arctic and Antarctic sea ice: volatility. Mainly at the edges, of course. That's because the ice is thin and doesn't get a chance to thicken because of heat/moisture via atmosphere and ocean.

To emphasis that point,  the previous record for the most daily drops in the 5 day average from November to January was 6, in 1980/1, 1983/4 and 2005/6. This year, we're already at 11.

[jdallen]

The image below just bins out the hycom thickness forecast for 04 Feb 17. At this rate, we'll be seasonally ice free for all practical purposes for a good portion of the coming melt season.

You' ve forgotten Nuclear Winter out of the Equasion...

Meddoc - everyone - please don't bring that here. It's hard enough as it is to stay focused without borrowing more trouble.

[Tigertown]

I have all the confidence in the world in Wipneus, but how accurate is JAXA on thickness? And how accurate does that make the graph?

I believe there is very little info on how the model works exactly, no peer-reviewed paper or some such.

I guess my thing is this: Are models showing gains right now in thickness and volume because that is what they are programmed to do or are there really gains? There are leads coming up every other day, though these usually freeze back over with thin ice between the dispersed thicker ice making scar ice, as I call it. It is obvious that the concentration is going down everywhere and you can see the front pushing out and breaking up as it goes. There is some freezing and some thickening in places, but it doesn't seem to be keeping pace with loss right now. Maybe that can change in February.

[NeilT]

Given that I'm always talking at a tangent to the main part of this thread I thought I'd finally buckle down to it and put out two graphs which you have never seen before because there is little interest in doing them.  Probably because, as far as I'm aware, there is not a lot of science in this area right now.

Given that we're saying that Volume is the key figure here and that Extent is simply no longer worth looking at and that area is better but thickness is key, I thought I'd base this on volume.

What I did was download the PIOMAS daily volume sheet and use Excel to calculate the maximum volume in winter and the minimum volume in summer/autumn, to give me the start figures.

I then trawled the solar sites to get the solar flux data and averaged that out to a single annual figure.

I then calculated one more figure.  Which was the volume loss for each year.  All of this for the last 11 years, 2006 to 2016.

The first chart is a comparison between the "volume loss" and the annual average solar flux.

The second chart shows the Annual max, the annual min and the annual average solar flux.

To align the values and make it a possible to compare I converted the PIMAS data from millions to hundreds of thousands (*10)

Attached below are the two graphs I made with Excel.

[jdallen]

Given that I'm always talking at a tangent to the main part of this thread I thought I'd finally buckle down to it and put out two graphs which you have never seen before because there is little interest in doing them.  Probably because, as far as I'm aware, there is not a lot of science in this area right now.

Given that we're saying that Volume is the key figure here and that Extent is simply no longer worth looking at and that area is better but thickness is key, I thought I'd base this on volume.

What I did was download the PIOMAS daily volume sheet and use Excel to calculate the maximum volume in winter and the minimum volume in summer/autumn, to give me the start figures.

I then trawled the solar sites to get the solar flux data and averaged that out to a single annual figure.

I then calculated one more figure.  Which was the volume loss for each year.  All of this for the last 11 years, 2006 to 2016.

The first chart is a comparison between the "volume loss" and the annual average solar flux.

The second chart shows the Annual max, the annual min and the annual average solar flux.

To align the values and make it a possible to compare I converted the PIMAS data from millions to hundreds of thousands (*10)

Attached below are the two graphs I made with Excel.

Apologies never checked the spelling in the charts.  fixing that in a sec.

Excellent!
Some questions.

Solar Flux is being presented in what Units?
Are we looking at departure from baseline?
What is the average and delta?

[NeilT]

The Gory Details, but in short

A measure known as the solar flux is
used as the basic indicator of solar activity,
and to determine the level or radiation
being received from the Sun. The
solar flux is measured in solar flux units
(SFU) and is the amount of radio noise
or flux that is emitted at a frequency of
2800 MHz (10.7 cm)

As I understand it this is an absolute value.  I don't believe it's an anomaly or a departure from a baseline.  It is never reported as such.

The averaging I did was the following.

I took the monthly smoothed values for the entire 12 months of the year and averaged them.

I took the SolarHam values for 2011 to 2016.

I took the rest from here.

It always seemed to me that there was a correlation between the flux at the end of a cycle and the beginning of the cycle and the extreme events we are now seeing in the melt seasons.

Note 2007, 2012 and 2016/17.



So I thought I'd take the values and graph them, yearly, against PIOMAS volume and see if there was some correlation.  Given that the sun is the single largest contributor of energy to the Arctic.

If you recall I was talking about 10 year and 5 year cycles.  To me it seems that the impact of the end of the solar cycle with the energy momentum of the solar high, has a different impact to the energy of the beginning of the cycle (2011/12), after the low.

Personally I think that whilst the ice cap was contiguous, strong and resilient to small changes in solar output, that it did not make that much difference.  However now it's weak and vulnerable, I think the small changes in solar output are being felt to a larger degree.

It's just a theory, but there is something there.  It just hasn't been going long enough to make an impression.

Well it was a thought.

[lifeblack]

The Gory Details, but in short

A measure known as the solar flux is
used as the basic indicator of solar activity,
and to determine the level or radiation
being received from the Sun. The
solar flux is measured in solar flux units
(SFU) and is the amount of radio noise
or flux that is emitted at a frequency of
2800 MHz (10.7 cm)

[...]

The measure of solar flux you have is the measure of solar activity during the solar cycle that produces radio emissions (sunspots/flares/etc).  The measure that I think you're looking for would instead be the Total Solar Irradiance  (see http://lasp.colorado.edu/home/sorce/data/tsi-data/ ).
However, I think the TSI is probably poorly linked to ice cover in the Arctic, since it doesn't include albedo effects (clouds, NH snow cover, etc) whose variability would swamp any correlation you're likely to see.

[A-Team]

Good comment, lifeblack. NeilT is totally off-topic. Again. Solar input after late August, preposterous. This cycle rubbish, recycled from his WUWT days, rebutted decades ago. Next up, ban him from the 2016/2017 season forum for distraction trolling.

[Jim Williams]

does it really matter what the absolute numbers really are? i mean, as long as we always compare...

The absolute number only matters when it is zero.  Until then I'd tend to agree that what is important is comparing apples to apples, and not to oranges.

[Tigertown]

The inner corner of the Beaufort is crumbling.

[NeilT]

Good comment, lifeblack. NeilT is totally off-topic. Again. Solar input after late August, preposterous. This cycle rubbish, recycled from his WUWT days, rebutted decades ago. Next up, ban him from the 2016/2017 season forum for distraction trolling.

Really?  Distraction trolling?  What a very interesting concept.

MY WUWT days?  Clearly, gone are the days when I get a cordial mention for taking down WUWT intransigence.  But, hey, that's life.

Solar input after late August,

Really?  That's going to hurt?  And just exactly where do these storms get their heat energy they are bringing  into the Arctic?  The tooth fairy?  Because it is not just the oceans.  Those weather events are born in the oceans which are in the light.

If that answer seems a bit harsh, then a review of the comment above might explain it.

And to answer a very reasonable question, no I was not looking for total solar irradiance because I was looking at the total solar activity.  Total solar irradiance factors in local phenomena affected by many factors such as local gasses and, as mentioned, albedo  Clearly total solar irradiance, in the Arctic, in winter, is a misnomer.  But total planetary impact by total solar activity is not.

Neven, you can ban me as requested, but, personally, this is the last time I accept the kind of comment I got above.  As the person who has put that comment in is a very prolific poster who provides very good graphics and data, I would expect that person to be valued far above my contributions.

It's been fun at times.  But it is no more.