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Chris Reynolds

idunno,

1) I suspect it is also a function of time of year, although there is very little difference in terms of insolation angle and the encroaching Arctic twilight between now and late August, which is only around 10 days away.

I also suspect it may be significant that for the last 20 days there seems to be a linear reduction in day to day losses. Note the stressing in italics. This reduction is not statistically significant.

2) Sorry I don't get this point at all. Early re-freeze anomalies are a different process to the period leading up to the minimum., and relate to the areas away from the pack at minimum, these areas need to loose a lot of heat to refreeze.

3) Let's keep in mind that 2007 was an exceptional situation where a relatively thick, strong ice pack was eaten into by an exceptional ice loss event. What we've seen in 2011 and 2012 is the massive loss of ice area/extent under pretty typical weather. I suspect this is due to the thinness of the pack, certainly as compared to 2007.

For what it's worth I accept the possibility that all that low concentration ice may still go. I am however prepared that it may not, and that losses may stall earlier than such considerations may suggest.

Either way we win - if the CT area loss rate picks up and continues through beyond the end of August then we know that the similarity between 2007 and 2011 was probably coincidence. If we see the loss rate reduce further after next week then the coincidence of 2007 and 2011 starts to need an explanation. And the best explanation I can see is that insolation has lost the battle against heat loss.

Fairfax Climate Watch

Looking at the animated charts on http://www7320.nrlssc.navy.mil/hycomARC/arctic.html , it seems like the intertia of the melting is pushing the extent to fall about another 25% through September; and moreover, looking at the rapidity of melting of even thick sections - plus the knowledge of how much heat has been entered into the ocean(s) - I wouldn't at all be surprised if extent dropped to zero this year.

The 25% estimation is probably above the extent reduction seen in 2011 from now to season close, but there is probably much more heat in the water up there this year, plus less ice, plus a large swath of ~1 m thick ice which seems to be steadily thinning.

Using some hypothetical rates I can see a few scenarios for rapid loss. For example, if the ice melts at an average rate of 4 cm / day from now through October first, a 1 m swath would be gone in 25 days without considering other factors. If I include the caveat that ice thinner than 0.4 m thickness breaks up and melts 4 times as faster than the ambient rate: (4 x 4 cm / day) = 16 cm / day when ice is below 0.4 m.

So, 60 cm / 4 cm = 15 days to 40 cm thickness; 40 cm / 16 cm = 2.5 days to 0 cm; 15 + 2.5 = 17.5 days for the 1 m swath to vanish.

For the 2 m swath, 160 / 4 cm = 40 days to 40 cm thickness (9_27_2012); and then the same 40 cm / 16 cm = 2.5 days to 0 cm. This would put the present 2 m swath at zero thickness on noon of September 30th.

Presently about 60% of the ice extent is in the 1 and 2 meter swath sections, so if the above scenario were to play out, and we use a value of 3 million square km today, we'd have 1.2 million square km on Oct. 1, 2012

But again, looking at the animations, I can see several examples when large areas of 3+ m thick ice melted to zero in just a few days. So you can see why I wouldn't be surprised by a zero extent minimum this year.

cheers,
Matt

Neven

Extent is not going to drop to zero (this year). Area is not going to go below 2 million.

Mind you, what we are witnessing right now is horrendous enough as it is. It doesn't need to be ice-free straight away to make it more horrendous. It is horrendous.

Jim Williams

Neven is probably right, but I bet area anomaly (CT's) will go well below -3M come October before shooting up to nearly normal in late Winter.

Next year is a hard call. Something is gone, but I don't know how long before the heat content overwhelms the ice.

Neven

Next year is a different story altogether. It might be worse, we might see a 'recovery' (yes, I'm being ironic) like we saw after 2007. We'll have plenty of time to speculate about that. But for the time being I think it's best to keep our heads cool and be careful when tying 'nearly ice-free' in with this year. It's bad enough as it is. Horrible even!

---

Something else that I hope someone can help me with. James Lovelock said the following during a BBC interview:

“Just the melting of all the floating ice in the Arctic Ocean will add as much heat to the earth as all the CO2 we put in the atmosphere to date.” BBC Interview 2011 with Prof. James Lovelock

Is this about correct? Albedo is not my strong point.

Seke Rob

Secondary effect to that Lovelock statement is, that energy is not going towards melting, keeping the temps "near surface" close to zero Celsius during the summer season. That DMI chart is going to be worth watching, this one, http://ocean.dmi.dk/arctic/meant80n.uk.php how much will that red line remain above base during the coming autumn winter. Mind you, this is above the 80N latitudinal where ice is still largely present.

Tor Bejnar

I'm very late to the Jimboomega thread, but one contribution to Arctic Sea Ice (ASI) maximum being relatively stable is the affect of the Arctic being mostly surrounded by land. (The regulars here know this better than I do, but I'm not sure if Jimboomega considered this.) We've seen a "slow" recession of ASI max area/extent which will continue its slow change until very late in the game, I suspect, probably until we're past the ASI free date. (I do not recall others on Neven's blog defining ice-free as being anything other than less than 1M sq. km. CT area at the autumn minimum.)

Aaron Lewis

Nevin,
It is hard to separate accumulated additional warming from the change in albedo from the additional warming from more water vapor (green house gas) in the air. Without the sea ice to condense water vapor out, there will be a lot more water vapor in the NH atmosphere. How large an area will be affected over what seasons is an issue.

Thus, the additional forcing is more than just the change in albedo. Soon, our weather is going to be different.

dorlomin

"Neven is probably right, but I bet area anomaly (CT's) will go well below -3M come October" Anomaly will most likely bottom out somewhere near the end of November early December.

Neven

But would you say it's largely correct, or is it - dare I say it - overly alarmist? Lovelock hasn't been the most reliable of sources on this subject.

R. Gates

Neven, I agree that area is not likely to go below 2 million sq. km. this year. Somewhere between 2 and 2.5 million seems the most likely target at this point. But I also agree that it is horrendous none the less. But what won't be horrendous as we approach a truly ice-free Arctic in the next few years? It's all going to be horrendous.

On a side note: Is anyone aware of a comprehensive analysis of the total enthalpy of the Arctic (including atmosphere, cryosphere, and oceans?) over the past few decades, similar to this one done for the global surface atmosphere:

http://www.agu.org/pubs/crossref/2011/2011GL048442.shtml

I would love to see some similar analysis applied to the past five years for total energy content in the complete Arctic environment. We all know how different each of the past 5 years have been in terms of melt dynamics, but I would love to see an analysis of the total energy of the Arctic in all forms including wind speeds, ocean temperatures, current speeds, latent, etc. My guess is this total enthalpy estimate would reveal a trend very similar (though likely steeper) to increase seen in the overall global ocean heat content down to 2000 meters:


http://www.nodc.noaa.gov/OC5/3M_HEAT_CONTENT/index1.html

Thus, we would see that while the individual years have their own melt characteristics based on natural variations, the total energy content shows a very steady increase and does not fluctuate as wildly as the sea ice area or extent alone might indicate, but each melt season has a different energy mix based on weather, and the total Arctic energy content shows a steady increase closely paralleling (or likely exceeding) the slope of the increase in global ocean heat content). In this regard of course, PIOMAS, though just a model, probably is the best over proxy or indicator of enthalpy of the Arctic, though is of course inversely related to the enthalpy.

Frankd 1977

A quick comment about multi-year sea ice. It is my opinion that the timing of this substantial drop in both SIA and SIE is due in part to the reduced survival of first year sea ice starting (in ernest) in 2007 and then every subsequent year. Thus the sudden evanescence of the 5+ year sea ice: The much harder ice that acts like an anchor or sorts, keeping the central arctic pack held fast to Greenland.

dorlomin

http://ocean.dmi.dk/arctic/icecover.uk.php

Domino 2, DMI? Can only be a day or two left.

Al Rodger

Hi Neven,
Is Lovelock right? This quote has been chewed over elsewhere in the past, although quite where slips my mind at the present.
The forcing solely from our CO2 stands at 1.9 Wm^-2. The figures quoted in the discussion for the reduced albedo from the Arctic ice loss were 0.1 Wm^-2 from present levels of reduction, 0.3 Wm^-2 from an ice-free summer & 0.7 Wm^-2 from a year-round ice free Arctic.

Al Rodger

Re Lovelock.
Happily Lovelock's quote has re-surfaced on a RealClimate thread of recent days so the reference fell readily to hand.
http://www.npolar.no/npcms/export/sites/np/en/people/stephen.hudson/Hudson11_AlbedoFeedback.pdf

crandles

>"The forcing solely from our CO2 stands at 1.9 Wm^-2. The figures quoted in the discussion for the reduced albedo from the Arctic ice loss were 0.1 Wm^-2 from present levels of reduction, 0.3 Wm^-2 from an ice-free summer & 0.7 Wm^-2 from a year-round ice free Arctic."

Presumably this is only effect on heat in during the summer. In reality, doesn't more heat at end of summer mean more heat loss during winter?

I would suggest that while you might get equivalent of +0.3Wm^-2 for an ice free summer, you would also get -0.4Wm-2 or even more negative during winter at current levels of GHG, air and water temperatures etc.

Going to ice free year round at current GHG level would, I guess, result not only in equivalent of +0.7Wm^-2 during summer but also get you something like -10.0+ Wm^-2 during winter.

Those negative numbers in excess of the positive numbers perhaps shouldn't be included because when it happens the GHG levels, temps etc will be up to levels where the negative numbers are the same as the positive ones.

So should the answer be close to zero for the year it first happens?

Or am I completely mis-understanding situation?

Chris Reynolds

Oh well I'll post anyway - it's taken me so long to write this after Neven's last comment that two people have replied.

Lovelock,

Current CO2 forcing around 1.5W/m^2 - that's for every meter of the planet.

The planet has a surface area of around 510M kmsq.

The Arctic ocean has an area of around 13.9M kmsq. That's 2.7% or the earth's surface area.

Now strictly speaking the CO2 radiative forcing of 1.5W/m^2 is at top of atmosphere. But even though the change in albedo in the Arctic is at surface if we assume the change in albedo is affecting top of atmiopshere visible light flux, we can compare the two.

So the Arctic would have to generate an extra 1.5 * 1/0.027 W/m^2 to match the global forcing of CO2. That's an extra 55W/m^2.

I'll assume that hours of insolation balance throughout the year. i.e. although there's no/little hours in winter this is balanced in summer.

http://en.wikipedia.org/wiki/File:Insolation.png
This suggests that surface insolation in the Arctic is of the order of 80 to 100Wm^-2. Call it 85 W/m^2.

Now for ice albedo - removing ice increases absorption by a conservative 60%. If we assume that under iced conditions 80% of the 85W/m^2 is reflected back into space, then under exposed ocean, 80% is absorbed, so that's 85 X 0.8 = 68W/m^2.

68W/m^2 is comfortably bigger than the 55W/m^2 that the Arctic would have to gain to rival CO2 emissions. So yes Lovelock's claim might seem to be in the right ballpark.

However - isn't there always a 'however' with me?

The full effect will only be felt once the ocean is ice free throughout the daylight months. So if my back-of-envelope effort is anywhere near correct we'll have to wait a while before it's correct.

By which time CO2 will have increase even more.

Chris Reynolds

Crandles,

"Presumably this is only effect on heat in during the summer. In reality, doesn't more heat at end of summer mean more heat loss during winter?"

But isn't this just the ocean acting as a storage cell, like a battery or capacitor. In the annual total the energy gained would be virtually the same.

Al Rodger,

Thanks for that useful paper. I suspect Loveock has carried out a back-of-envelope calculation as I've done. I'd trust a modelling study more than such calculations.

dorlomin

"But isn't this just the ocean acting as a storage cell, like a battery or capacitor. In the annual total the energy gained would be virtually the same."

It would be a storage cell of sorts but it would mean open water for much of autumn as energy is released back into the atmosphere. This will change weather patterns.

Also much thinner ice is an energy gain and the open water would have quite a significant water vapor feedback through the late summer.

Al Rodger

Hi Chris Reynolds,

As I did back then. His interview (a U-tube version here http://climateforce.net/2012/01/11/bbc-james-lovelock-interview-2011/ ) was in April 2011 so it pre-dated the paper, otherwise I might have put it down to him misreading the "...similar to present-day anthropogenic forcing caused by
halocarbons.
" as 'caused by carbon dioxide.'
As I remember, my back of fag packet calculation for ice-free summer came out as 0.5 Wm^-2 but above today's ice conditions, so quite a lot higher than Hudson.

Chris Reynolds

Dorlomin,

But if we're talking about direct RF due to reduced sea ice the heat released in autumn would be like a battery/capacitor discharging.

Al,

Thanks for the context. Years ago I found Lovelock's Revenge of Gaia quite alarming. Now I think it's rather threadbare. Hansen's alarming proclamations have more force from my reading.

Tor Bejnar

Although the CT Arctic Basin area is not at a record low (yet), its anomaly has broken the 2007 record.

Bfraser

@Tor Bejnar

Actually, we haven't broken the record.

During the refreeze, 2007 set a record which should survive until this year's refreeze (unless the area falls below 2.1).

2012.6246 -2.2613978 2.9423456 5.2037435
2007.8000 -2.6349814 4.4081578 7.0431390

AmbiValent

I think Tor Bejnar was referring to the anomaly of the Central Arctic Basin alone, not that of the total Arctic Seas.

Tor Bejnar

I was referring to what Cryosphere Today calls the "Arctic Basin"; I looked at their anomaly graph here. "Central Arctic Basin" can refer to areas with different boundaries, unless, I suppose, one refers to CT's Central Arctic Basin (sic).

Tor Bejnar

Besides CT's AB referenced above, this year CT's Barents Sea area anomaly approached the 2006 anomaly record. The CT Kara Sea 2012 anomaly probably set a record; the 2006 "record" looks decidedly suspect on the graph - I'm sure the area did not plummet to zero for a day. All the other CT areas have not shown spectacular early melting this year, based on the anomaly graphs.

Bfraser

Sorry about that, Tor. You are, of course, correct that we've set a record for the CT Arctic Basin Anomoly.

(Somehow, I missed the "Basin" when I read your claim. The claim it self was clear enough when I re-read it...)

martinw

Re: Bremen vs NSIDC, I came across this comment:

http://www.livescience.com/16083-arctic-sea-ice-2011.html

[Bremen] use a satellite sensor that can detect ice cover at a higher resolution than that used by NSIDC. The two groups probably came up with different results because this year ice was more dispersed in the water, and the Bremen group was able to pick up on details, leading to more variability between the two sets of measurements, Meier said.

If all else were equal, once might infer that the higher resolution sensors used for the Bremen data would make this a more accurate result. Would be interested to hear opinions on this.

martinw

Oops. That last paragraph in the above posting was my own comment, not a quote from the article. Basic html usage failure. Is there a way to edit comments that I'm missing? (Note to self - use Preview button next time before conferring immortality on masterpiece.)

Also note that the quote is from 2011, but the principle should still apply.

Neven

Martin, Uni Bremen was using the AMSR-E sensor last year that broke down in October. So last year can't explain this year.

Luckily, ASMR2 will be online soon.

martinw

Neven, thanks for the insight (and html fix). I see that now on their page. I also see they have a large disclaimer there stating the new results they are posting are experimental and need to be used with caution. So maybe wise not to put too much weight on the absolute values this year.

http://www.iup.uni-bremen.de:8084/ssmis/index.html

Paul Klemencic

Really bad forecast for this week… a low pressure system near S.Z. with a high pressure centered near the north coasts of Greenland and CA should form a strong Arctic dipole anomaly. The winds should start stripping away the shattered pack near the NP, and by Friday, the ice pack around the NP should be fractured. The odds just went up considerably that we might see open water at the NP this melt season.

Given all the open sea to disperse the weakened floes stripped from the pack, I expect significant open water up to 87N in the vicinity of the Laptev bite.

By Friday's report, SIE will set new lows in most reports.

Aaron Lewis

Lovelock has made estimates of AGW that are much higher than the concensus values in the peer reviewed literature, but it appears that the peer reviewed literature numbers are much lower than reality. Lovelock might well be closer to reality than the peer reviewed literature.
In all of analysis regarding increased forcing from loss of sea ice, no where do I see a realistic treatment of the increased water in the atmosphere as a greenhouse gas. Hudson, DOI:10.1029/2011JD015804, 2011 , in particular does not differentiate between ice clouds with a very high albedo and other types of clouds.
The real question is does water vapor concentration go up just over the Arctic, or over does water vapor concentration go up over much of the NH or even all of the NH. If a drop in sea ice raises the water vapor content over all of the NH the forcing effect of the loss of sea ice could be much larger than anyone here has suggested.

And, a moist Arctic is going to rapidly deposit (flash freeze) snow to reduce winter radiation. Snow is a very good insulator and it floats on cold sea water.

Syddbridges

It is fascinating, in a morbid kind of way, to see the different measuring systems, in their own time, move towards new records. I would not expect them all to break records at the same time as they are using different methodologies and are measuring different things. However, the results seem as inexorable as divine retribution in a Greek tragedy.

Putting on a "skeptic's" hat and using a massive dose of Doublethink, I think I can hear the WTF crowd saying, "Look, they're not accurate! They didn't all show the same thing at the same time." Of course, if all the records fell at once, they would say, "They can't all show the same thing at the same time. They're colluding with Al Gore, the U.N. etc." Such is the beauty of Doublethink, as George Orwell explained so well. And don't forget the record refreeze to come. Even if it doesn't get up to that of previous years, the lower it is now, the greater will be the ratio of 2013's maximum to 2012's minimum. "Every cloud has a silver lining." Even an ice-free September would be spun as a victory, because any ice in the winter would be an infinite ratio increase over none in the summer.

crandles

>"The real question is does water vapor concentration go up just over the Arctic, or over does water vapor concentration go up over much of the NH or even all of the NH."

Well absolute humidity does go up in response to temperature. But is more open water in arctic going to raise absolute humidity beyond the temperature effect that you would expect?

With typical lifetime of water vapour in the atmosphere at about 11 days, I really can't see much effect in tropics or extratropics on absolute humidity except in response to temperatures.

What is the lifetime of water vapour in the Arctic? Maybe lifetime is longer because precipitation occurs when air rises and generally air is falling in the arctic. So this could cause high absolute humidity as the moisture is quite prone to stay in the atmosphere for a long time until the air is blown out of the Arctic?

Whatever, I do imagine sizeable increases in amount of both evaporation and precipitation.

Please correct me where I am wrong.

Jim Williams

The question about water vapor was interesting enough that I went and found this:

http://arctic.ssec.wisc.edu/data/view-data.php?action=view_image&product=images/ARCTICWV-L.GIF

Now to look about the site and or other search results similar to "water vapor north pole satellite" and see if I learn something.

Artful Dodger

New paper out from GRL on Aug 14, 2012:

Nussbaumer, E. A. and R. T. Pinker (2012), The role of shortwave radiation in the 2007 Arctic sea ice anomaly, Geophys. Res. Lett., 39, L15808, doi:10.1029/2012GL052415.

Key Points:

  • Shortwave radiation not the driver of 2007 Arctic sea ice anomaly
  • Importance of high quality information in addressing climate in the Arctic
  • Cloud information is consistent with information on radiative fluxes

Yeah, it wasn't the cloudless skies (2005 had fewer clouds), it was the warm Pacific inflow (4 TJ heat inflow to the Chukchi sea).

R. Gates

Dodger,

Thanks for that link to the Nussbaumer & Pinker (2012) paper. This kind of analysis gets back to my point from my post earlier today-- the total energy in all forms in the Arctic needs to be estimated. The notion that SW radiation was not the driver of the 2007 Arctic sea ice anomaly may be accurate IN REGARDS TO SW OVER THE ARCTIC, but the bigger picture is missed in this kind of analysis. Energy from lower latitudes is transported to the Arctic via multiple means in both atmosphere and ocean. It is the global increase in energy in the Earth system caused by increasing greenhouse gases and the transport of that energy via various means to the Arctic that needs to be considered when analyzing the "cause" (as though there was a singular cause) of the decline in Arctic sea ice and the general warming of the Arctic. We know for example, that a great deal of energy is being transported to the Arctic via ocean currents as the global ocean energy content increases. Certainly the global increase in greenhouse gases is directly related to this increase. But the increased frequency of the dipole "anomaly" is yet another way that more energy is transported to the Arctic, and of course, we all know the results of that in terms of Arctic sea ice. Additionally, of course, intense cyclones such as we saw earlier this week is yet another way that net energy is transported to the Arctic.

Susan Anderson

For northern hemisphere water vapor, this might make you crosseyed, and of course there's that blank, but it's fascinating:
http://synoptic.envsci.rutgers.edu/site/sat/sat.php?sat=nhem&url=../imgs/wv_nhem_anim.gif
(other options at top of page)

R. Gates

In my last post, the last sentence should have read:

"Additionally, of course, intense cyclones such as we saw earlier this month is yet another way that net energy is transported to the Arctic."

George Phillies

It is perhaps noteworthy that the DMI graph at http://ocean.dmi.dk/arctic/icecover.uk.php has resumed the remarkably rapid drop that it was showing when the Great Arctic Cyclone descended. The amount of recent steep drop seems larger than 'hiccup without significance'. Extrapolating that rate through to the end of August, even though we are in a period when in past years the rate of decay of 30% ice cover seems to have been fairly constant over the month, appears optimistic; trending below the 2 million level. The rate of decline of the DMI 30% ice is still impressive.

Anu

Posted by: R. Gates | August 19, 2012 at 05:03
It is the global increase in energy in the Earth system caused by increasing greenhouse gases and the transport of that energy via various means to the Arctic that needs to be considered when analyzing the "cause" (as though there was a singular cause) of the decline in Arctic sea ice and the general warming of the Arctic.

We know for example, that a great deal of energy is being transported to the Arctic via ocean currents as the global ocean energy content increases.

Yes, that's exactly right.
I would like to add that there is already a great mass of warm water underneath the sea ice, kept from touching the bottom of the ice by the haloclines (salinity gradients). I think the thickness is about 50 meters of low salinity, cold water separating the sea ice from 150 meters of water of steeply rising salinity and temperature. As the boundaries of the sea ice "continent" shrink each summer, exposing more Arctic ocean to wind and sun - and more frequent storms - this formerly placid halocline "barrier" gets breached in more and more places near the ice-open-water boundary, mixing deeper, warmer water with the surface, cold barrier water - then melting the sea ice above.

So, in addition to the annual increase in energy that makes its way to the Arctic, there is the unleashing of energy that is already there, but formerly not being used for bottom melt.

I think the "Laptev Bite" (long thin melt area) is an example of this. As the receding sea ice shore allows the new winds and currents to travel above 80° N in the Laptev Sea, the haloclines between the Lomonosov and Gakkel Ridges
http://img402.imageshack.us/img402/9232/arcticoceanfloor.jpg
are being vertically mixed: in recent summers, we see that long, thin meltout right above the 5000 meter deep gorge between the ridges. I think detailed modelling of the ocean current eddies in this location would show the surface layer mixing - right now it's just a hunch.

Note the "bite" almost reaches up to 85° N now:
http://www.iup.uni-bremen.de:8084/ssmis/arctic_SSMIS_visual.png

R. Gates

Beautiful photo from the Healy late on the 18th of August, 2012:

http://icefloe.net/Aloftcon_Photos/albums/2012/20120819-0401.jpeg

This broken sea ice in the area that received a direct hit from the cyclone. Note how calm the water is now with an almost perfect reflection of the clouds in the water.

Neven

Good thinking, Anu!

Chris Reynolds

I'm working on some data people might want to use, so I need to know the preferred anomaly baseline period of 'the community'.

I use 1980 to 1999, a 20 year period that throws into contrast the accelerated change of the 2000s. But I suspect only I use that baseline period.

Suggestions? Comments?

Russell McKane

Take note of the Nares Strait at the moment , comparing the latest Breman image 18th with Lance- modis 08/18 ro3co3 there is obvious insitu melting going on - could it be that the Nares is reverse flowing with warm water from the Baffin sea into the central arctic. While not conclusive yet Bouy movement in this reagion apears to be moving north.

johnm33

Russel I tabbed 5 images from A4R's new site, then + at the source of otto fjord,then clicked through, seemed to show the same thing.

crandles

CT Area
2012.6274 -2.2484031 2.9199340 5.1683369

still not quite there

AmbiValent

It's less than 1K over 2007, and just over 15K over 2011...

Werther

Today we have a virtual tie on minimum area between ’12 and ’07. The remaining 495 km2 is hardly significant. Just one good floe…

Tomorrow the CT area domino will fall.

On IJIS extent, while the daily drops are still in the neighbourhood of centuries, matching last year takes just two, matching the ’07 record just five days.

Kris

Russel made the remark:

Nares is reverse flowing with warm water from the Baffin sea into the central arctic.

Well, it makes sense.

After all, Greenland's West coast is the "warm side" of the island. As we can see every year when the melt season starts: Greenland's West coast get's rapidly cleared from ice due to the warmer, or better less cold water streaming to the North.

Now, as the ice is detached from Greenland's Northern coast it could well be the "normal" way is free and the perfect convection got it's way: a stream to the North at the West Coast, and then at the outer North the water pushed Eastwards to the Fram strait and from there back to the South. A perfect convection circuit.

If it would be like that, it would be quite an amazing novelty. Even more amazing than the records you guys are longing for. :-)

Werther

Hi Kris. I'm not longing for a record. I'm afraid. While in this circumstance of danger there's no option to fight nor flee, I'm sitting here paralyzed, just staring at photo's and graphs.
Think I'll have a beer to relax. It's sweltering out here. 92 F is a little bit to much for the Netherlands.

Paul Klemencic

More bad melt news… The IJIS reported its third century break in a row for August 18 final number. Normally we would be noticing this kind of streak, but of course this year the abnormal has become the normal. (Just how many century breaks this month?)

At 4.7M sq km, the lead over 2007 melt has increased to about 440k sq km, ignoring leap year. This week the lead should increase to over 550k, and if that lead holds until minimum, we would see a minimum extent probably below 3.7 M sq km for IJIS.

Why will this week be bad?

1st - the Bremen map shows significant broken ice blocks and floes in the CAB above 80N up to 86N all along the eastern side of the pack.

2nd - this side will be subjected to at least five days of continuous wind pushing the ice blocks and floes toward the Fram. With plenty of open sea in this direction, this next week could see ice move 30-40km per day for five days, so as much as 200 km toward the Fram.

3rd - Next weekend, a decent storm should form in the Chukchi, and then move toward the Beaufort. This should do a number on the Beaufort region ice pack.

Lots of records, significant pack movement, and scattered ice blocks and floes… Looks like a disastrous week!

But hopefully the last really terrible week of this melt season.

Apocalypse4Real

In response to the Arctic water vapor and air flow/winds comments by crandles and others, I ran across this presentation yesterday that mght be of interest:

"Using AIRS Moisture Retrieval Data to Derive Atmospheric Motion Vectors"

http://airs.jpl.nasa.gov/documents/science_team_meeting_archive/2012_04/slides/Santek_AIRS_May_2012.pdf

dabize

Just a heads up to Neven - I'm sending him a declouded "portrait" of the CAB.

Kind of reassuring, actually, but there's still plenty of cloud.

Apocalypse4Real

The August 18 sea ice concentration and thickness maps are updated. Please note the new link:

https://sites.google.com/site/apocalypse4realseaice2012/home/sea-ice-concentration-and-thickness-comparison

Also, given the previous discussion of potential Nares Straight reverse flow of warm water into the CAB, I added an extra ice thickness map with a selection of ship and buoy air and sea temp readings as of approximately 1800, 18 August. It is on the same web page. The ship and buoy data come from:

http://www.sailwx.info/shiptrack/shiplocations.phtml

There is a new site I have in development to track Arctic methane.

Twemoran

Russel - Kris

Nares Strait flows in both directions, but the far larger flow is from the north, on the west side of the channel.

Terry

Frankd 1977

Paul K: "The IJIS reported its third century break in a row for August 18 final number. Normally we would be noticing this kind of streak, but of course this year the abnormal has become the normal. (Just how many century breaks this month?)"

Technically the decrease didn't quite make the 100K mark (92.5K), but I know what you mean. I've been counting the daily decreases in the 90s as century dips too; especially since 3 day this month alone the dips were almost 200K :)

In answer to your question: 12 days this month have seen validated daily decreases of 90K or more.

8/3 108125
8/4 115468
8/5 94532
8/6 188437
8/7 170469
8/8 175312
8/10 105938
8/11 97344
8/16 102500
8/17 116407
8/18 101875
8/19 92500


101875
92500

Seke Rob

Re Twemoran | August 19, 2012 at 17:28

Gibraltar does so too, at the surface in, at to bottom out, which has to do with dumping the salt load. Net, the Med takes water in. Then when it goes into the Atlantic, the current dives deep. Some papers have been written on what would happen if that current were to slow or halt [There've been some, who thought of damming the strait [Atlantropa http://www-das.uwyo.edu/~geerts/cwx/notes/chap11/mow.html , noting the name of S.Rahmstorf popping up in this short, a frequent contributor to the Real Climate blog]

Paul Klemencic

Frankd, I don't use the latest day of IJIS data until revised. My comment related to the three century breaks on August 16,17, and 18.

Paul Klemencic

The MASIE regional charts marked as August 18 are up, but the data they show corresponds to August 6th. The reporting lag problem has grown to 12 days this year, from 5-6 days last August and September. The last three days on each chart shows August 4th, August 5th, and August 6th.

The charts (and accompanying data) show huge losses in SIE in the Beaufort (146k), E. Siberian (112k), and Chukchi (49k) totaling 307k sq km lost on Stormy Monday. August 6th was the first big day of the Great Arctic Cyclone of 2012 (GAC-2012), after a couple of days of century losses as GAC-2012 rolled in. MASIE data shows the Arctic ice cap lost SIE on Stormy Monday of 335k, an extremely rare triple century break! In fact, has this ever happened before? We may not know the answer to this question, because of the averaging procedure used in the other products.

The MASIE data is likely the best measure of both the daily total, and regional ice losses due to this storm. MASIE was designed with the tightest grid (4 km) of any of the SIE measurement systems, and has multiple sensors, not relying on passive microwave (PM) alone. MASIE was designed to give the most accurate data on the edge of the ice pack on the observation day of any of the products (which is why the dating problem with the reports is rather frustrating).

IJIS gives a reported 188k loss for August 6th, but averaged a lot of the drop into the August 7th reported decline of 170k, and even some of that drop; into the August 8th reported decline of 175k sq km. It will be interesting to watch the next two days of MASIE data to see how GAC--2012 really hit these three regions.

Interestingly, now correcting for the dating issue, the MASIE SIE of 5.41 M sq km for August 6th, is likely at least 300k lower than what the daily IJIS was (prior to averaging) for the same date, but thus appears to be more in line with the Bremen graphed SIE. Last year we were able to get some daily reported data from the Bremen product, and the SIE generally reported lower than IJIS by about 300k in August. Bremen also uses a tighter grid than IJIS, as does MASIE, and may be giving a more accurate SIE report. If the dating problem with the MASIE reports is corrected, then apparently IJIS becomes the odd man out, showing a higher SIE than the other products.

In spite of the dating problem with the MASIE reports, it still gives the best regional information that can be used to assess the melting rate, and effects of storms, prevailing winds, and weather systems, on the critical ice pack edge. Stripping away the protective lower latitude ice pack floes, exposes the important contiguous Central Arctic Basin ice pack to warmer water and increases the heat transport and heat transfer to the ice in the CAB. The MASIE regional reports are important to assessing the health of the ice pack, and predicting loss of extent.

(Peter Ellis: you may continue to disagree with this assessment, but then what is your explanation of a triple century break, if it happened yesterday? I await your explanation.)

Hans Kiesewetter

Re:Amu, 19 Augustus 06:56: is this the reason Polarstern is heading toesta the Laptev Bite? After all, the titel of their expedition is -XXVII/3 "IceArc" (Sea ice - ocean - seafloor interactions in the changing Arctic"

dabize

Anu,

I find your idea quite compelling, as the prevailing movement of warmer seawater in the region is presumably from the west - i.e. from the Atlantic via the Barentsz Sea, making the Gakkel Ridge perfectly placed to force an upwelling of warmer, saltier water at the Laptev Bite, where either property could be expected to increase melting. The increased water movement itself would increase heat transfer, exacerbating the melt still more.

The devil is in the details, though.

Things as plausible as that have occasionally turned out to be coincidental in this world.........

David Einstein

I have a question. In order to get an idea of the movement of the central Arctic ice I have been attempting to follow buoy 100004 on the Daily Nares Strait map. http://iabp.apl.washington.edu/maps_daily_naresstrait.html .
Neither the position nor the track seems to have changed at all since late June. The daily table http://iabp.apl.washington.edu/maps_daily_table.html lists buoy 100004 as being Obuoy4, and the tracks of 100004 and Obuoy4 http://obuoy.datatransport.org/monitor#overview/gpstracks seem similar up to the point that Obuoy4 teleports and 100004 stops. Are these actually the same buoy? How reliable are the rest of the tracks on the iapb site? Can we accurately judge the flow near the Nares Strait with these buoys?

Anu

@Hans Kiesewetter | August 19, 2012 at 18:58

Thanks for the info - I didn't know the Alfred Wegener Institute research vessel was heading right towards that seafloor Gakkel Ridge, but you're quite right:
http://expedition.awi.de/

http://www.awi.de/en/infrastructure/ships/polarstern/weekly_reports/all_expeditions/ark_xxvii/ark_xxvii3/

54 international scientists and technical teams will investigate the biology, chemistry and physics of sea ice and the impact of sea ice loss on the entire Arctic Ocean system.

The expedition IceArc will focus on the interactions between hydrography, ice physics, biogeochemistry and biodiversity in the Arctic system, from the sea ice to the deep-sea floor. By integrated process studies, sites in the central Arctic with no sea ice cover, at the ice edge and in multiyear sea ice will be compared. Ice-, ocean- and seafloor moorings will be deployed to observe sea ice thickness, circulation of Atlantic water and corresponding particle flux throughout the year.

Sounds interesting.
I wonder how detailed and 3D their "circulation of Atlantic water" studies will be.

And yes, I hope they look at the Latptev Bite more closely...

TenneyNaumer

We appear to have a new Arctic cyclone north of Greenland at about 85 degrees N.

Satellite photos:

http://climatechangepsychology.blogspot.com/2012/08/new-arctic-cyclone-north-of-greenland.html

Peter Ellis

Peter Ellis: you may continue to disagree with this assessment, but then what is your explanation of a triple century break, if it happened yesterday? I await your explanation.

Easy enough.

Firstly, look at MODIS for the 17th and 18th. The clouds parted, allowing IMS/MASIE to update areas they hadn't properly seen over the last few days.

http://rapidfire.sci.gsfc.nasa.gov/imagery/subsets/?mosaic=Arctic.2012230.terra.4km

http://rapidfire.sci.gsfc.nasa.gov/imagery/subsets/?mosaic=Arctic.2012231.terra.4km


Secondly, the thin ice across the Chukchi is finally letting go. Compare the 13th (last clear day near Barrow) to the 18th.

http://rapidfire.sci.gsfc.nasa.gov/imagery/subsets/?subset=Arctic_r05c03.2012226.terra.367.1km

http://rapidfire.sci.gsfc.nasa.gov/imagery/subsets/?subset=Arctic_r05c03.2012231.terra.367.1km

See that great swirl of milky red going all the way past Point Barrow on the 13th that's gone now? That's not seen as ice by the microwave satellites - the last time Bremen had any ice there was the 1st of August. The thin remaining ice is however detected by MODIS, which is the primary data source for MASIE. Yes, MASIE has (some) element of delay when there are clouds around, but the bigger factor is that it sees thin, sparse ice that the microwaves don't.

See this reference, for example, particularly figure 9C.
http://www.knmi.nl/publications/fulltexts/new_sea_ice_detection_quikscat_final.pdf

The heavy dashed line is the ice edge as estimated by passive microwave. The other two lines are two different algorithms when applied to active microwave (i.e. radar) data. During the melt season, passive microwave simply misses a lot of sparse ice compared to other data sources. It has the opposite bias during the re-freeze: Figure 9A shows newly-formed thin frazil ice that's visible to passive microwave but not to radar.

Money quote from the article:

"In general, the combined MODIS and ASAR records confirm that all the sea ice detection algorithms under study come to agree within 25 km over areas that do not include mixed ice/water pixels (i.e. thin, low concentration or rotten sea ice). Fig. 9A shows a typical detection discrepancy involving newly formed thin ice off the New Siberian Islands in the Arctic. The QSCAT-SCP algorithm [i.e. old radar algorithm --Peter] is missing a large tongue of new ice with dark smooth appearance in the image, which is detected by both the QSCAT-KNMI [newer radar algorithm --Peter] and AMSRNT2
algorithms [passive microwave data --Peter]. Note that the presence of frequencies of up to 89GHz in passive microwave methods plays favorable to thin ice detection during the growth season due to their lower penetration depth. Fig. 9B shows a typical example of summer biases in the Beaufort Sea, featuring a large expanse of decaying and water saturated ice missed by the AMSR-NT2 algorithm, which the QSCAT-SCP method can only detect partially. Fig. 9C provides another instance of summer biases along the ice edge in the Southern Ocean, this time featuring a number of ice bands of varying concentration. Low concentration, wave battered, decaying and water saturated ice are all examples of diffuse ice edge conditions most likely to be underestimated by passive microwave sea ice concentration
algorithms.
"

TenneyNaumer

Sorry, I have a simple blog -- to see the photos, hit the page down key a few times:

http://climatechangepsychology.blogspot.com/2012/08/new-arctic-cyclone-north-of-greenland.html

Peter Ellis

Heh, just look at the IMS images for the 17th and 18th (the main input source for MASIE)

http://www.natice.noaa.gov/pub/ims/ims_gif/ARCHIVE/AK/2012/ims2012230_alaska.gif

http://www.natice.noaa.gov/pub/ims/ims_gif/ARCHIVE/AK/2012/ims2012231_alaska.gif

There's your 300k. Note that it includes the ice near Barrow, which was visible on MODIS after the storm, so no, it's not just the storm effects showing up late.

Tor Bejnar

A month ago, both before and after the Kane Basin ice bridge collapsed, I reported ice moving in a gyre within the Kane Basin (southward on the west side). After the bridge broke, but while ice was basically blocked from exiting by a large floe temporarily caught in the Kane Basin gyre (at the Basin's mouth), I noticed (not reported because clouds prevented certainty) that ice was not particularly accumulating in the Kane Basin, and possibly melting in situ. I'm interested to hear that the Kane Basin gyre is part of a larger Nares Strait 'flowing both north and south' and others perceiving in situ melting.

The 2012 Petermann Ice Island is slowly moving toward Baffin Bay (southward) on the Canadian (west) side of Nares Strait.

Twemoran

Tenney

The cyclonic area will see ice radiating away from the center, unless it's already compacted enough to prevent movement.

Tor

Dr Muenchow has links to a paper of his that discusses Nares Strait currents in depth (and at depth:)

Everyone

If you haven't yet utilized Arctic.io's new split zoom feature, you're missing some of the detail of what's been happening, particularly in coastal areas still clinging to a remnant of fast ice. I can't recommend this interface enough.

Terry

OldLeatherneck

Terry,

Was this current cyclone anticipated, or is it just another surprise in a very surprising Arctic Summer of 2012.

BTW, I appreciate your insightful comments that an amateur can comprehend.

JackTaylor

Posted by: TenneyNaumer | August 19, 2012 at 20:53

Tenney, thanks for the "heads-up" on a new cyclone. Will it be The Great #2 of 2012?

TenneyNaumer

Terry, that sea ice is all crumbled. Here is the latest MODIS image:

http://rapidfire.sci.gsfc.nasa.gov/cgi-bin/imagery/single.cgi?image=crefl1_143.A2012232162000-2012232162500.250m.jpg

Twemoran

OldL

I don't know if it was anticipated as I've come to have little faith in the forecasts for the Arctic. I think we're in uncharted territory'

As for your kind remarks, if I'm communicating well with amateurs, it's probably because I am one.

Terry

TenneyNaumer

Jack, I am not a very good prognosticator when it comes to things like Arctic cyclones. Here is the 36-h outlook:

http://weather.unisys.com/gfsx/gfsx.php?inv=0&plot=hght&region=nh&t=36h

The sea ice flows out a lot faster than it did back in 2007. Just about anything is going to flush it out into the North Atlantic if the wind blows in the right direction.

The way the cyclone sits just now, it looks like it will blow it from west to east along northern Greenland, which is already its natural direction.

Neven has ice drift map here:

http://www7320.nrlssc.navy.mil/hycomARC/navo/arcticicespddrf/nowcast/icespddrf2012081818_2012081600_035_arcticicespddrf.001.gif

CryoSat-2 shows that the thickness in that area is about as pitiful as it gets:

https://dddeb0d3-a-62cb3a1a-s-sites.googlegroups.com/site/apocalypse4realseaice2012/home/sea-ice-concentration-and-thickness-comparison/Ice%20Thickness%20081812.jpg

Artful Dodger

Hi folks,

We're in the home stretch so it's time for some final predictions.

IJIS 2-day SIE Sep 8/9: (defined as the final value reported as Sep 9, 2012)
4.10 M km^2, +/- 0.2 M

This prediction is derived by taking the pessimistic date-of-min SIE as Sep 9, then finding the rate of SIE loss for the remaining 22 days from Aug 18. The years with the highest loss (2008) and lowest loss (2006) are tossed out, and then the Min, Max, and Avg loss is computed.

Note that 2012 must average just -21,222 km^2 day to set a new IJIS record by Sep 9. And note that 5 of the last 7 years (2005-11) have averaged greater than that loss, so roughly a 70% chance of a new record by Sep 9.

This purely statistical approach ignores WX anomalies like the strong dipole at end-of-season 2011, and any further loss of SIE after Sep 9.

OldLeatherneck

Two Questions:

1. In previous years, has there ever been open water extending from the northern exit of the Nares Strait across the northern tip of Greenland to the Fram Strait?

2. If there is such a path of open water this year, will warmer waters flowing north from the Nares Strait delay or reduce re-freezing along the north coast of Greenland ain any significant way??

Timothy Chase

Tenney Naumer wrote:

CryoSat-2 shows that the thickness in that area is about as pitiful as it gets:

https://dddeb0d3-a-62cb3a1a-s-sites.googlegroups.com/site/apocalypse4realseaice2012/home/sea-ice-concentration-and-thickness-comparison/Ice%20Thickness%20081812.jpg

That's CryoSat? I thought no data was being made publicly available at this point. The link you provided is to a Godiva2, second image in New site with new thickness maps.

OldLeatherneck

Artful Dodger,

I fear that we would be very fortunate for the SIE minimum to occur on the 9th of September.

Although I'm not a statistician, I did plot the end date for the IJIS - SIE for the last 32 years and performed a simple linear trend analysis. There seems to be a trend trend towards later ending of the melt season, however due to the vagaries of weather the standard deviation is 6 days.

The trend shows end date to be about the 13th. And with curent conditions and happenings, I expect a later end date.

Chris Reynolds

OldLeatherneck,

1) Not that I've seen.

2) I don't think so. Flaw leads on the coast are common with tides and ice movement. They can as easily close when the wind changes as they opened.

Chris Reynolds

Tenney Naumer,

The last link in your message is from model output, not Cryosat.

Aaron Lewis

Crandles,
In the old days, the Arctic was so dry that water vapor would sublimate from the very cold ice, thereby further cooling and hardening of the ice. Now, there is so much water in the Arctic that liquid water sometimes falls from the sky : )

As a rule of thumb water vapor tends to condense on ice. Thus, how long water vapor stays in the air over ice depends on how still the air is. Air containing more latent heat tends to move more. Air that moves more tends to bring more water vapor into contact with the ice. (Every gram of water vapor then melts 7.5 grams of ice resulting in 8.5 grams of runoff!)

The traditional story of water vapor has it starting in the south and moving north, condensing out as it meets cold, dry air from the North. What happens if it never meets cold dry air from the North? Then less of the water condenses out, and the water stays in the air longer, and there is more water vapor in the air. And what happens, when a mass of moist air is born in the Arctic and moves south? It does not meet cold air, the water does not condense out, and then we just have more water vapor in the air, sitting there, just waiting to all fall out of the sky at once.

idunno

Hi Aaron,

My limited physics, much of it gleaned from this blog, tells me that the same amount of energy needed to melt 1 gram of ice would raise the temp of 1 gram of water by 80Centigrade.

So how does 1 gram of water melt 7.5 grams of ice?

Twemoran

Aaron

Wonder if northern Inuit dialects have a word for rain.

Terry

dabize

Terry,

I'm sure they have at least one. Places that were historically without any rain at all (Ellesmere I?) are unlikely sites for permanent habitation by anyone.

An more ghoulish rumination might be whether they have a word for "sleet", and if so, will now have to learn the difference between it and "hail".............

crandles

>"condensing out as it meets cold, dry air from the North. What happens if it never meets cold dry air from the North? Then less of the water condenses out, and the water stays in the air longer, and there is more water vapor in the air."

Umm, isn't that backwards? If air from south meets colder air (nearly as cold as before) but moister air (not like before) then water vapour is more likely to condense out than when it was meeting dry air. But AFAICS this could be part of increased evaporation and precipitation cycle I expect rather than changing (reducing?) water vapour levels beyond what you would expect for the temperatures.

As for the extratropics, yes the moister cold air warms up and can take more water vapour. However the equilibrium is quickly reached by 11 day lifetime. While the air coming from the arctic is moister than it was and might slightly increase water vapour levels, the main effects could easily be to reduce evaporation and precipitation in the extratropics.

TenneyNaumer

Chris, please, can you explain to me about the model output? What data does it use to model thickness? I guess I mistakenly thought it was coming from CryoSat2.

Twemoran

dabize - There actually were regular encampments by Inuit and before them Dorset culture people on Ellesmere Island. The Dorset actually left stone "foundations" behind. They all seem to be located close to polynyas.

I think Peary land, with zero precipitation, until recently, was devoid of settlement though.

Terry

dabize

Bet those encampments were seasonal rather than permanent (in the sense of year -round).

The polynyas make sense if the settlements were made by people who were there for the fishing. It's easy to see how they might get to parts of Ellesmere in the summer. Wintering over would be tricky, though.

As for Peary Land, wouldn't it be pretty inaccessible pretty much at all times to Inuit who had to travel by kayak?

Peter Ellis

idunno: Latent heat of evaporation is much larger than latent heat of fusion.

Twemoran

Dabize - We're probably drifting a little off topic but:

Attended a lecture re the Ellesmere Island stuff last winter by a friend in the OAS who had done research at one of them this past summer, I think he found they were seasonal but I will be seeing him in a few months and will enquire.

I believe there was evidence of an encampment by Dorset at or near Independence Fjord, but not have been Inuit habitation, The Inuit were mining iron from a huge meteorite (that Peary swiped) that was quite a ways inland - but closer to the west coast I believe. Both cultures hunted sea mammals, but both also went inland for muskox and caribou IIRC

Sorry will try to stay OT in the future. The only possible linkage I can claim is the reference to changes in precipitation.

Terry

Twemoran

Espen may be interested in noting that the northern spit of fast ice grounded on Belgica Bank has been rotating in a clockwise direction, not rapidly, but enough to keep a sharp eye on it during the upcoming spring tide.

79 had apparently receded at least as far back as Blasco from 7.7k yrs.BP until 4,5k yrs BP, the recent freshening of the water near it's outlet (as seen using the ARC SSS animation), may be indicative of things to come.

http://www.geus.dk/publications/review-greenland-98/gsb183p56-60.pdf

Terry

Apocalypse4Real

Hi Tenney,

The source is something covered in a previous post. It is not CRYOSAT 2 data, I wish it was.

These sea ice concentration and thickness maps come from the GODIVA2 Data Visualisation.

The UK data I have been tracking in Godiva2 is put out by the UK, The National Center of Ocean Forecasting (NCOF). The NCOF is a strategic partnership between the Met Office and the Proudman Oceanographic Laboratory, Plymouth Marine Laboratory, National Oceanography Centre, Southampton and the Environmental Systems Science Centre (ESSC) at Reading. The GODIVA2 data is output by the ESSC. See http://www.ncof.co.uk/OSTIA-Daily-Sea-Surface-Temperature-and-Sea-Ice.html

The NCOF uses the Operational Sea Surface Temperature and Sea Ice Analysis (OSTIA) data for sea surface temperature and sea ice concentration and thickness analysis. OSTIA uses satellite data provided by the GHRSST project, together with in-situ observations to determine the sea surface temperature. The analysis is performed using a variant of optimal interpolation (OI) described by Martin et al., 2007. The analysis is produced daily at a resolution of 1/20° (approx. 5km). See http://ghrsst-pp.metoffice.com/pages/latest_analysis/ostia.html

The GHRSST project, which is the source of the 5km data, is an international satellite observation project. It consolidates imagery and data from a number of hi-res platforms. See: https://www.ghrsst.org/ghrsst-science/what-is-ghrsst/

I hope that helps.

A4R

LRC

This year, Greenland experienced extreme melting in nearly every region -- the west, northwest and northeast of the continent -- but especially at high elevations. In most years, the ice and snow at high elevations in southern Greenland melt for a few days at most. This year it has already gone on for two months.

"We have to be careful because we are only talking about a couple of years and the history of Greenland happened over millennia," cautioned Professor Tedesco. "But as far as we know now, the warming that we see in the Artic is responsible for triggering processes that enhance melting and for the feedback mechanisms that keep it going. Looking over the past few years, the exception has become part of the norm."
Found this @ http://www.sciencedaily.com/releases/2012/08/120815121318.htm
Seems to indicate that warming AO also means shrinking Greenland icecap. Didn't even mention that fact that with less ice blocking the glaciers, those glaciers are going to move even faster.

TenneyNaumer

Thank you so much, A4R! How are the validations going?

Artful Dodger

OLN: yes, I have also notice the trend to later dates for Summer min SIE (and Winter max SIE).

I've just assumed an early end to the melt season, and it still has a 5-in-7 chance of setting a record by Sep 9. You could easily recalculate using this method for any future date. Let's see where we're at on Sep 9. My guess is 4.10 +/- 0.2 M km^2 by the 9th.

After that, it all depends on the winds. September ice movement determines if the latent heat stored in the ocean goes into further melt (the Dipole Anomaly case) or is radiated out into space (the light winds case).

I think the Sep 9 milestone will be informative. We'll know in 3 weeks.

Paul Klemencic

Peter Ellis: Thanks for your help diagnosing the mistaken dating of the MASIE maps and data.

When I talked to the project lead for MASIE last Friday, she agreed that the PM maps from two weeks ago matched the current MASIE map fairly closely (as I was on the phone, she compared the August 1st/2nd Bremen map with the August 16th MASIE map).

If the problem was with the MASIE software though, they would need funding to have someone check the code.

Then you replied to me on this thread, and in your comment included the link to the IMS maps (from the National Ice Center, NIC, which is a joint effort by the US Navy, NOAA, and US Coast Guard).


I realized immediately that MASIE was getting mis-dated input data. The NSIDC of NOAA gets the input data for MASIE from the NIC. I sent an email to Florence early this morning, and she got back to me immediately:

Thanks Paul, it absolutely helps. I'll try to connect with NIC, where IMS is produced. As you can imagine they are extremely busy right now!

Florence

At 6:47 AM -0700 8/20/12, Paul Klemencic wrote:

Subject: Re: Dating problem seems to start with the IMS Product
Date: August 20, 2012 7:50:14 AM PDT

Florence:

I looked at the IMS Product page and they have the same dating problem on the maps and data.
It seems MASIE is getting mis-dated input data...
I don't know if this helps any.

Paul

Paul Klemencic

To keep this MASIE stuff off the main discussion threads, I will put the latest data discussion here:

The August 19th MASIE data is out (probably for Stormy Tuesday August 7). SIE fell another 253k on top of yesterday's 335k… whew, 588k in just two days! The reported losses are consistent with comments from the NSIDC that SIE extent fell over 200k per day for two consecutive days during the storm.

MASIE shows the big SIE regional losses were in the Beaufort (86k), Chukchi (80k), Laptev (39k), E. Siberian (17k), and CAB (15k). The losses were consistent with the location of the storm circulation on Stormy Monday/Tuesday.

The entire Arctic SIE was 5.16 M, compared to 5.76 M and 5.59 M reported by IJIS for August 7th and 8th. Since IJIS uses an averaging procedure of 3-5 days, MASIE likely shows 300-400k less than IJIS for that time period. The Bremen graph for the storm dates seems to show SIE falling below 5M in the first couple of days. Again, IJIS seems like the odd man out, now that we know the MASIE data is mis-dated due to input data problems from NIC.

Seke Rob

MASIE Updated... OK, good time to do another quadrifoglio, but it's not bringing any luck to the sea ice [and more things affecting climate]: http://bit.ly/MASDMI

Finally, that resistance is futile bit of 18km^2 counted under the Barentsz went... another MASIE region gone zero. Baffin the next one with 2,657 km^2... but that one is fed at least through Nares, or is it the the discussed reverse flow keeping the ice floes away at this time? At least, the MASIE multi-year regional plot does not indicate it having gone so low in 5 years. ftp://sidads.colorado.edu/DATASETS/NOAA/G02186/plots/r08_Baffin_Bay_Gulf_of_St._Lawrence_ts.png

Paul, for all your analysis and logic, something tells me the difference is just the way they [MASIE] compute the last day,... their docs saying "manual data fusion, at 4km resolution (16Km^2)".

2. When should I use MASIE and when should I use the Sea Ice Index?

Use the Sea Ice Index when comparing trends in sea ice over time or when consistency is important. Even then, the monthly, not the daily, Sea Ice Index views should be used to look at trends in sea ice. The Sea Ice Index documentation explains how linear regression is used to say something about trends in ice extent, and what the limitations of that method are. Use MASIE when you want the most accurate view possible of Arctic-wide ice on a given day or through the week. More accurate pictures of ice extent on any given day might be possible on a regional basis and from other international centers. See the IPY Ice Logistics Portal for access. If you have a question about intended and appropriate use of the data, please contact NSIDC User Services.

A hint that there an apple - orange element.

IJIS is 2 days BTW.

cheers

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