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Artful Dodger

Thanks for the reference, Timothy. I did a quick back-of-the-napkin calculation today. I estimate that Antarctic land ice volume is least ~1,300 X greater than the Antarctic perennial sea ice volume (assuming end-of-Summer sea ice area is 10 m thick on average):

(25.4 million km^3)/(19,630 km^3)=1,294

This ratio is even greater if multiyear Antarctic sea ice is thinner than 10 m on average.

So any claim made that Antarctic sea ice is increasing, while simultaneously ignoring mass balance of the Antarctic ice sheet, are spurious at best or an outright deception at worst.

Artful Dodger

Thanks again Timothy. That paper provides useful data:

"The ICESat record shows the 2003-2008 mean ice volume reached a minimum of 3,357 km3 in the summer, grew to 8,125 km3 in the fall, and reached its maximum of 11,111 km3 in the spring."

So (ignoring the annual cycle in land ice volume), the ratio of Antarctic land ice to sea ice volume by season is:

Spring: 2,300 x land/sea
Fall: 3,100 x land/sea
Summer: 7,600 x land/sea

That end-of-Summer ratio is the same as the largest elephant known (10,900 kg) vs a 1.44 kg chicken (a small fry).

(the last known photograph of 'Snarky the Chicken')

Steve Bloom

We are collectively pecking the trunk, thinking that nothing could possibly go wrong. :(

Timothy Chase

Artful Dodger quotes:

The ICESat record shows the 2003-2008 mean ice volume reached a minimum of 3,357 km3 in the summer, grew to 8,125 km3 in the fall, and reached its maximum of 11,111 km3 in the spring.
I missed that bit.

Entertaining comparisons!

Artful Dodger

De nada. Nuestra situación no es más que David contra Goliat. A menos que seamos demasiado pollo.

Steve Bloom

BTW, Neven, maybe you've already noted the answer somewhere I haven't seen, but has "flashing" come to an end?

Neven

Steve, the big flashing is over, but I'm still seeing a lot of changes from day to day that should keep area and extent declines going down steadily. Another smaller ice atoll has detached itself from the main pack.

FrankD

Lodger,

That para you quote goes on to say: "Thus, the amplitude in the annual cycle of ice production and melt (less ice export) was ~8000 km3. This annual cycle of ice production and melt is larger than that of the Arctic which has an annual ice production of ~3400 km3, though a higher maximum
ice volume of 16400 km3 in the spring (Kwok et al., 2009)."

Now I find two things about that rather strange.

1. If Antarctic Sea Ice Volume is 11111 km^3, and the area at max is ~15 M km^2, that means the average thickness is only 60-70 cm, which seems remarkably low.

2. Even stranger is the implication (unless I completely misread) that summer minimum volume in the Arctic is ~13,000 km^3 (ie max volume less annual ice production). I don't maintain PIOMAS v2.0 (Wipneus does a superlative job with it), but version 1.0 had the ice production for 2008 (2008 max - 2007 min) of approximately 17,000 km^3. I know v2.0 is flatter, but not by a factor of 4, surely.

All seems quite odd. To be fair, I've only skimmed it, so I probably missed something obvious.

Peter Ellis

Even stranger is the implication (unless I completely misread) that summer minimum volume in the Arctic is ~13,000 km^3 (ie max volume less annual ice production).

That sounds about right for historical minima - agrees well with PIOMAS and with the recent Guardian article. As for why they show such a low winter maximum, I would imagine they're looking only at the Arctic basin and excluding the Bering Sea, Hudson Bay etc.

Artful Dodger

FrankD mate,

Let's do a little work to improve our estimate of Antarctic Sea Ice Area (SIA). NASA provides ICESat/GLAS campaign dates in an Excel sheet, available here:
Laser Operational Periods

Using these NASA campaign dates to find the corresponding CT SIA, the average Antarctic SIA is 2.776 M km^2 during the 6 Summer campaign periods (2004-2009).

With avg volume over the ICESat era given as 3357 km^3, our estimate of ice pack thickness during the Summer campaigns is 1.21 m. We can also define the perennial ice pack as this sample of volume & area.

Next, we can use our estimate of perennial sea ice to more tightly constrain the bounds on seasonal sea ice.

Let's make the following 2 assumptions:
1. The perennial ice pack in Antarctic is in thermal equilibrium, and has no trend in annual area or volume
2. All growth in sea ice occurs in the seasonal ice pack
(these assumptions are FALSE, but will serve our purpose of setting an upper bound on thickness for the seasonal ice pack ;^)

====

{ WHEW! -- continued in my next Comment}

Cheers,
Lodger

crandles

Does anyone imagine the storm will have destratified the ocean enough to slow the freezing such that freezing might occur from edges inwards rather than from centre towards edges? Or is this a completely mad thought?

Jim Williams

crandles, the bulk of the anomalous warm water is still to the south. Unless things change over the next month that seems unlikely.

Fairfax Climate Watch

crandles: http://www.whoi.edu/itp/images/itp53dat3.jpg if correct, this bouy in the Chuchki sea http://www.whoi.edu/page.do?pid=75657 shows a breakdown of stratification barriers. My impression is that the research community is actively trying to measure and understand the stratification of the Arctic, but as yet do not have a sufficient monitor network.

I don't see any reason why, with the major CO2 forcing currently in effect, a dramatic change in sea currents and Arctic stratification couldn't lead to something like what you suggest above. I hadn't thought of that myself, but it's an interesting idea.

If stratification is broken down, or even reduced, then the energy required to vertically mix the water falls significantly. Considering the interesting bathymetry of the Arctic, coupled with the constricting inflow/outflow regions and the Coriolis effect, the region reminds me of the inards of a gnarly water pump. Perhaps a new ocean current pattern will emerge where warm Atlantic and/or Pacific waters flow in such a way to prevent sea ice from forming in both Summer and Winter.

crandles

Jim, the anomalous *temperatures* are still to the south, yes. But what about heat? If the high water temperatures are shallow water that may mean less heat to be lost before freezing commences? I really haven't a clue how that compares to a long column of mixed water where the warm water might keep rising to the surface while salty and cold water sinks. Does that provide enough turbulence to keep the salt mixed and therefore the freezing point low and lots of heat through the column to be lost before freezing commences?

Jim Williams

OK crandle, let's pull up a polar basin map: http://www.soest.hawaii.edu/hmrg/Aagruuk/DataCompilation/index.htm (that was the first thing Google gave me....)

I'd say that on the Russian side you could be correct. North of Alaska, not so much. So....a mixed bag.

More likely, this year at least, would be a confusing picture.

I'm not yet completely convinced we'll have a normal freeze-up at all, and it's the mixing of layers I'll be watching.

www.facebook.com/profile.php?id=687386516

I really don't think the buoy data from the super-storm is reliable. Looking at the profile for buoy 53 a breakdown of stratification barriers seems to have occurred approximately 25-30 days before the storm. Why was that?

In an article by Krishfield et al (2008) under a chapter discussing instrument performance of prototype ITPs (chapter 6a) they say the buoys had difficulties collecting profiles when the ice speed was larger than 50cm/s. In some cases the buoys failed to sample more than 10 meters down.

Looking at the drift speed of buoy 53 at the time of the storm it was around 60-70cm/s. This is incredibly high. 25-30 days before the super-storm the drift speed was also over 50cm/s.

/Daniel

www.facebook.com/profile.php?id=687386516

Sorry about the links in my previous post. Would you please correct the broken links, Neven? [Fixed, N.]

I should also have mentioned to press "Plot of ITP Buoy Status" to read drift speeds over time on the last link.

/Daniel

Neven

NSIDC has an analysis of the storm.

Bfraser

Hey, Neven. Did you notice they called it the Great Arctic Cyclone of 2012?

Oslo

The GAC2012, now official ;-)

Neven

Yes, I noticed it, Bill. Well, like I said in the piece I did for ClimateProgress:

Someone on the Arctic Sea Ice blog proposed to call it the ‘Great Arctic Cyclone of 2012′, but this can probably only be done in retrospect. For who’s to say that we won’t be seeing more of these Arctic summer superstorms in the near future?

But I think R. Gates came up with the best name. I like it much better than 'Arcticane'. I'll use it in this way: 'the summer storm, already dubbed the Great Arctic Cyclone of 2012, etc, etc...'

crandles

Putting
http://farm8.staticflickr.com/7228/7047926277_21a704df26_z.jpg
next to/below current position e.g.
http://www.iup.uni-bremen.de:8084/ssmis/index.html

is that old MYI in A and further up now on the edge of the pack and getting rather holy or has it have moved northward? Or southward and melted? Is it succeeding in slowing the advance of the melt or taking a battering?

Fairfax Climate Watch

Daniel, thanks for the link to the paper about the bouys.

Fairfax Climate Watch

Current anthropogenic CO2 is equivalent to volcanic CO2 of 3500 Mt. St. Helens per year..or if you prefer, one or more supereruptions per year (of a megavolcano, like the Yellowstone cauldera). Hmmm... and the arctic ice is supposed to do what now?

source:
http://www.agu.org/pubs/pdf/2011EO240001.pdf

www.facebook.com/profile.php?id=687386516

This weeks MODIS composite image is out. This is what a huge storm and two weeks of melting looks like 2012:

Before
http://ice-glaces.ec.gc.ca/prods/MODISCOM-F/20120730000000_MODISCOM-F_0006568207.jpg

After
http://ice-glaces.ec.gc.ca/prods/MODISCOM-F/20120813000000_MODISCOM-F_0006593535.jpg

johnm33

We may have another storm by this time tomorrow, the first links animations, cice especially, show the action for the last month really well, and how the ice is now almost all north of 80deg,except for CA. The second a new low pressure zone which has emerged from eastern siberia and has been blowing water up through the bering st. if it follows it's current trajectory it'll pick up lots of that anomolous heat from the mckenzie bay area and do some real damage to the ice remaining below 80degN, but wherever it moves to it's difficult to see how it wont rip a couple more centuries.

http://www7320.nrlssc.navy.mil/hycomARC/arctic.html
http://ocean.dmi.dk/arctic/weather/arcticweather_imagecontainer.php

Rob Dekker

Ambivalent said :

Stratification question: The storm may have de-stratified the sea in the area it moved through, but wouldn't the sea be pushed back into the stratified state? The salty water should still be heavier than the fresh surface water moving in from the sides, so it would fall, and melting also provides for more freshwater at the surface.

Great questions. Indeed, the de-stratified area will stratify again, but the question is when that will happen. As I pointed out in my post, models are not yet capable of simulating disturbances like this, this deep and this wide as what just happened.

From the literature, it is pretty clear that re-stratification typically happens "laterally". This means that salty water will move in from the sides, which re-establishes the 'blocking' of heat transfer between surface and deep ocean.

For local heat transfer "chimney" effects, it takes a few days to re-establish stratification, but once again, this storm is different. It covered about 1 million km^2 area, and thus re-stratification may take more time.

From the two ITPs in the area (ITP41 and ITP53), ITP41 was further out, and it seemed to have restored stratification to near-normal situation after a week or so :
http://www.whoi.edu/itp/images/itp41dat3.jpg

ITP53 however (being still on the outskirts of the storm, albeit a few 100 km inward) still shows significant de-stratification all the way down to 500 meter) :
http://www.whoi.edu/itp/images/itp53dat3.jpg

If ITP41 re-stratified after a few days, then ITP53 will probably re-stratify after a few weeks. but two ITPs is really insufficient data for such an assessment.

In fact, I would give a few bucks for some more ITP data closer to the center of the storm, but apparently we as a nation have believed that one extra F22 raptor is more important than putting a bunch of ITPs in the Arctic to monitor halocline disruptions which could tell us exactly why the Arctic is changing much faster than any of our models projects, so that we may understand a bit more on why our climate is changing.

With only two ITPs in the area, and uncalibrated models not much help, we are really somewhat in unprecedented territory here, so I would like to ask if out collaborative scientific knowledge may help in answering the following questions :

(1) Which physical mechanism may be responsible for disrupting deep ocean currents down to 500 meters, disturbing the lower halocline in the process ? Ekman pumping / spiral is supposed to affect only the upper 20 meters of water...

(2) How quickly will a de-stratified Arctic re-stratify and what are the variables that affect that re-stratification process ?

(3) How much does extra salt at the surface affect fall freeze ?

(4) Now that it has become clear that a significant summer storm severely affects summer ice extent (loosing a record 1 million km^2 in one month in the process), what will be the effect of summer storms in the summers to come, which will have even thinner summer ice available...

Rob Dekker

Sorry guys. "loosing a record 1 million km^2 in one month in the process" should read "loosing a record 1 million km^2 in one WEEK in the process".

Artful Dodger

Since we got started with this thread on why Antarctic Sea Ice is dwarfed by changes in the Antarctic Ice Sheet (land ice), I'll continue here. There's a new paper in JGR on Aug 21, 2012:

Kurtz, N. T., and T. Markus (2012), Satellite observations of Antarctic sea ice thickness and volume, J. Geophys. Res., 117, C08025, doi:10.1029/2012JC008141.

Key Points:

  • First ever study of Southern Ocean sea ice thickness and volume changes
  • Comparisons with available in situ data support the accuracy of the results
  • There is relatively little change in sea ice thickness and volume in Southern Ocean


Neven

An interesting article with interesting quotes by several scientists: AtmosNews.

Artful Dodger

Our friend Bob Henson from UCAR could be inspired by you, Neven:

"As Shakespeare noted about true love, the course of Arctic sea ice never does run smooth.

Well, we do know he reads the ASI blog... ;^)

Cheers,
Lodger

Neven

The ice thou hast, its adoption tried, grapple it to thy soul with hoops of steel...

Artful Dodger

Here's a link to the ESA webpage about the Aug 23-25, 2006 Arctic Cyclone: (984 mb central pressure)

http://www.esa.int/esaEO/SEM7ZF8LURE_index_0.html

The webpage, published Sep 19, 2006 notes, "this cyclone was observed by Envisat’s Advanced Synthetic Aperture Radar (ASAR) and AMSR-E aboard the EOS Aqua".

It's interesting to revisit the comments and predictions about the future of Arctic sea ice made just 6 years ago.

Neven

Thanks a lot for that, Lodger. It'll be interesting to have a look at what that storm did to extent and area. Don't have the time to look right now, but apparently it wasn't enough to beat the 2005 record at the time.

Artful Dodger

Here's a beautiful animation generated from AMSR2 data during the period of the Great Arctic Cyclone of 2012: (h/t Patrice)

Wispy clouds swirl about in shades of dark blue, look beneath them to watch the pack ice shrink.

Cheers,
Lodger

Artful Dodger

Gotta phone in this MODIS image of hurricane Issac captured today just offshore of New Orleans. Central pressure was 970 mb when it made land fall. Compare that to the Great Arctic Cyclone of 2012 which had a central pressure of 964 mb. Issac's sustained winds were 80 mph. So what does that say about the winds for GAC-2012? Click the image below for a larger version.

Fairfax Climate Watch

That animation is just stunning! Looking at that Gulf hurricane I really can grasp the immensity of those forces that were unleashed on the glass-jawed sea ice.

Artful Dodger

Good example of just why/how much we need to fund Earth Observation programs by NASA + ESA + JAXA.

I hope one of our clever/resourceful contributors here at the ASI blog can locate some wind vector history for GAG-2012.

Cheers,
Lodger

Boa05att

Commenters here have pointed out a stunning feature made clear at the University of Bremen Sea Ice page. With a little searching I found an animation that makes it even clearer.

The image above covers the last 30 days of melting. At the 5 second mark, you can see an enormous blob break free in the Chukchi Sea area, fly apart and disappear in the anomalously warm ocean water.

In the last few frames another huge mass in the central arctic seems about to pull away and dissolve in a similar process. I’m learning to read these images along with everyone else, but it would seem that whether it eventually melts or freezes in place is dependent on how much longer this process continues.

http://climatecrocks.com/2012/08/30/sea-ice-update-the-long-dissolve-of-2012/

Seke Rob

O O O Ozone layer damage. Just wanted to append an entry made by Wayne Davidson on his EH2R site with the title: "How important is Stratospheric Ozone vs Severe weather?", where he did cyclone predictions but calls them tornadoes. Search his site http://www.eh2r.com/ or the entry WD June 10, 2012 . There are no topic hyperlinks.

Artful Dodger

Here is a paper relevant to GAC-2012. It discusses the Beaufort sea cyclone of 24 Sep 2010:

Inoue, J., and M. E. Hori (2011), Arctic cyclogenesis at the marginal ice zone: A contributory mechanism for the temperature amplification?, Geophys. Res. Lett., 38, L12502, doi:10.1029/2011GL047696.

Key Points:

  • Using a meteorological research vessel, we caught an Arctic cyclone at ice edge
  • The cyclone had the identical life-cycle to a mid-latitude one
  • The cyclone is essential for meridional and air-sea heat exchanges in the Arctic

I'm sure we'll see much more of this come out studying GAC-2012.

Cheers,
Lodger

Apocalypse4Real

Lodger - see my comments on signs of Arctic Climate change. We are thinking through the same issue - but you are more eloquent and knowledgable about it.

Artful Dodger

Here an animation showing winds during Aug 2012, including the time of the Great Arctic Cyclone. Well worth an update I think, Neven!

h/t LRC | September 20, 2012 at 02:34

Cheers,
Lodger

Apocalypse4Real

Lodger,

It is a great video - wish we had more updates.

Artful Dodger

I expect some excellent papers covering this storm, 3 years after the Summer sea ice is gone :^(

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