« Open Thread 3 | Main | Open Thread 5 »

Comments

Feed You can follow this conversation by subscribing to the comment feed for this post.

Daniel Bailey

Nice bear. Did you take it (and thanks for the link)?

The Yooper

Neven

Hi Yooper, I'm the bear (hibernating)! ;-)

I'm copying the last comments from the discussion in Open Thread 3.

Artful Dodger wrote:

Let's return to the topic of albedo flip, which is what happens when lost sea ice is replaced by dark liquid water in the Arctic Ocean. Sea ice reflects about 70% of incoming shortwave radiation, but open ocean reflects only about 7% of the Sun's energy. This albedo flip makes a 10-fold difference in Solar heat input to the Arctic Ocean, and is critical for estimating when the perennial ice pack will collapse.

Let's get started. If we know the ratio of open water to sea ice, and the amount of incoming solar energy, we can calculate solar heat input to the Ocean. This will be used in the heat budget, later.

Solar insolation from 70N to the Pole averages about 100 W / m^2. Allowing for clouds and atmosphere, ~70 W / m^2 reaches the ocean surface (useful as a 1st approximation).

If 70 incoming Watts hits sea ice, only about 21 Watts / m^2 is absorbed, due to the 0.7 albedo. However, if it hits open ocean, about 65 Watts is absorbed. Now here's the inspired bit which we will use later: when the Ocean is partially covered with sea ice, then total solar heat absorbed can be calculated if we know the proportion of sea ice to open water.

We have a measure of this 'compactness' of the sea ice pack. At the ASI blog, we call it CAPIE (the ratio of Cryosphere today Area Per IJIS Extent). For example, on July 15, 2010 CAPIE was about 69.5% so we can estimate the heat absorbed by the Arctic Ocean above 70N at about 34 W / m^2.

Using this technique, we can create summary statistics for Summer 2010, which are an estimate of the total solar heat input for the season. I have a tad more spherical trigonometry to do, then I'll be back with another comment continuing this topic.

---

Peter Ellis wrote:

Eh, compactness isn't the right figure to use.

Let's say you have a given amount of ice at a given compactness. Now, pretend the left half of it vanishes instantaneously. Area and extent are both halved, but the compactness is unchanged.

What you want is the ratio of the ice area to the total sea area. Moreover, since the denominator of that is fixed by Earth's geography, you can cancel it out and just use ice area as a measure of how much extra sunlight is being absorbed.

If you want to do better than that, you'll need to adjust for latitude on a pixel-by pixel basis over time.

---

John Thiessen wrote:

To understand what 300 km^3 means for sea level rise:

The area of the oceans are 335258000 km^2 (from google or whatnot). For each km^3 that melts, the oceans rise 1/335258000 km. To convert to meters, multiply by 1000. That still leaves a very small number. To make that number more comparable, multiply by 1000 again: 0.00298. In other words, for every 1000 km^3 of land ice that melts, the sea level rises .00298 meters or about 3 millimeters. So the current rate of sea level increase due to Greenland melt (approx. 300 km^3) is about 1 mm per year.

Does this sound right?

Andrew Xnn

1mm/year from Greenland sounds about right (maybe a little on the high side).

Current sea level rise is about 3mm/year with about half from melt and half from thermal expansion. Between Greenland, Antarctica and all the other Glaciers; all the other Glaciers are generally thought to be the more significant part.

When the next IPCC report comes out, I'm sure there will be an update on this.

Neven

For people who haven't read it at the time, here are two links that explain how compactness (and in our case CAPIE = Cryosphere Area Per IJIS Extent) works, and when and how it becomes useful as an indicator of melt ponds and divergence in the ice pack (which relates to compaction potential at the end of the melting season):

Area vs Extent (August 1st)

and

Area vs Extent: Graphs (August 4th)

Artful Dodger

No, Peter. I am estimating the heat budget within the perennial ice pack. The mechanical properties of sea ice make the pack ice a separate domain from the Ocean. Here's an example:

By Aug 31, 2010 the SST gradient in the East Beaufort sea was up to 22 C over 150 km. Warm water did melt the ice edge, but Sea Ice physically separated the interior of the pack, preserving the perennial ice pack.

As long as temperature gradients persist, your approach will not work. Heat is stored separately in the Ocean, then released to the atmosphere in the Fall, without ever adding a calorie or KJ to the central pack ice. This is not the knock-out punch that will cause the sudden loss of the perennial ice pack.

Talking to the BBC about Arctic Sea ice in 2007, Maslowski said: "In the end, it will just melt away quite suddenly". What I am after is a description of the mechanism for that complete collapse. Think of popping a balloon, verses deflating one.

dorlomin

In terms of the "alarmist dilemma" I think there is no dilemma. We want the minimum climate disruption possible. We want the minimum sensitivity possible, the most boring examples to point too. We have won the argument in almost all the democracies of the world excepting America and 150 years after the Origin of Species we are still trying to convince the bulk of Americans that evolution is real.

We won the arguments when people believed it would be 2100 before we seen a ice free arctic. Every year of higher sea ice extents is fantastic news for humanity. I really don’t want to be poking an even angrier climate bear than we already are just to win on the internet.

Kevin McKinney

I don't know what "the wake-up call" for denialism will have to be. In fact, I think that it's quite possible that there may not be a single, dramatic, turning point.

I do think that education about real consequences of AGW is very important to prepare the ground, though. For example, high food prices--I've been stressing threats to agriculture and food security as the most salient threat that climate change poses to humans. It's not a "strategic" decision per se; it's that I think that is very likely to be the case.

If that case is made to the public at large sufficiently, then there is presumably a greater chance that they will be ready to consider whether AGW is part of the problem being experienced--as opposed to simply scapegoating ethanol. (Which predictably will be attempted, of course.)

Similarly, drought and flooding. (Part of the agricultural challenges, of course.) If think that awareness of these facets of AGW is still pretty low among the general public, and that it behooves us to do what we can to educate on that score.

Slow, tedious, and frustrating, perhaps, but so it goes.

Kevin McKinney

Make that "I think," not "If think!"

FrankD

@Lodger: What I am after is a description of the mechanism for that complete collapse.

The interview you quote gives hints: "The ice is thinning faster than it is shrinking; and some modellers have been assuming the ice was a rather thick slab."

The following is not intended as a realistic projection, but is for illustrative purposes. Suppose we just extend the loss of area (IJIS) and volume (PIOMAS) in 2010 linearly.
2010 minimum area was 4,000,000 sq kms, down 481,000 sq kms on 2009. September (average) volume was 4080 cu kms, down 1500 cu kms on 2009.
Extrapolating from that you would expect:
2011 area 3,519,000, volume 2580.
2012 area 3,038,000, volume 1080.
2013 area 2,557,000, volume is ... oh, b***er....

While volume is falling quickly and area / extent are holding up, the effect is to increase the surface area. A 5m slab thinning into a 4m slab shows little change; V/SA is reduced, but the actual surface area drops slightly, so overall change is marginal. But a wide area of ice with an average thickness of <1 metre changes radically when thinned some more. Holes start appearing, larger slabs break into smaller slabs etc increasing the surface area over which ice is melting and accelerating loss (average albedo also decreases, as you observe). The pack is also more mobile, making it more susceptible to advection and also to further mechanical battering. It suddenly becomes vulnerable to a number of forces that are not really in play with thick ice.

With the last two years seeing almost all of the remaining multi year ice transported to the Beaufort and melted there, almost the entire pack is now close to that "tipping point" where further thinning produces positive feedbacks (of which decreasing albedo is one).

To me, surface area is critical, and is not really adequately represented by any current measure or combination of measures. CAPIE (though I prefer IAOE - IJIS Area Over Extent) can in some cases, but does not all. For example, the Petermann Ice Island single 260 sq km lump, is quite different to a 625 sq km space dotted with 260 sq kms of broken up floes.

The ice cubes in a drink take a lot longer to melt than crushed ice, even if the total amount of crushed ice is greater.

BTW - Albedo for a surface can vary with the angle of incidence of the light (I don't know if it does for ice, but I think it does for water). Are the figures you are using regarded as constants or averaged for a range of sun angles?

Artful Dodger

Hi Frank. Yes, thickness of the pack ice is important. In fact, PIOMAS uses the area of July sea ice < 40 cm thick to predict the September minimum. This ice is vulnerable to both melt-through and bottom melt, but it still has high albedo. So solar forcing has not changed.

I'm describing the way a small increase in proportion of open water within the pack ice causes a big increase in solar heat absorbed. When the pack is one-quarter open water, it absorbs 50% more of the Sun's energy than fully ice covered ocean. When the pack is half open water, it absorbs 100% more energy, and so on. This is the albedo flip, and it can be the mechanism for the collapse of the perennial ice pack.

Compare these two sea ice concentration maps for Jun 21, 2010 and Sep 3, 2010. Notice how much more open water there is toward the end of Summer. We will use CAPIE to estimate solar forcing, and then extend the technique for the entire Summer season.

Again, 70 W/m^2 is the average value for solar insolation at the surface, from 70N to the Pole. As you anticipated, I'm doing the trig to estimate the change in Sun angle over the Summer. Reflectivity is a Newtonian concept, light is actually a quantum of energy delivered by a photon. This issue is handled by calculating the equivalent area exposed to the Sun for a given angle of incidence.

Phil263

Kevin @ 23.58 "I think that it's quite possible that there may not be a single, dramatic, turning point."

Totally in agreement with you and this is the main issue with awareness about climate change. This is about climate not weather .
With the current floods we are experiencing in Queensland, I hear people saying " It is because of AGW" or invariably : It is not really getting dryer or hotter, is it ? so these stories about AGW must be rubbish!". As far as I know, the current weather has one main explanation; two Spanish words " La Nina". What is the relationship between AGW and ENSO? I blelieve that nobody really knows at this stage.

Of course, the change in climate is going to be reflected in patterns not in actual events and unfortunately, by the time we realise patterns have changed, we will be helpless.
I believe that Australia is at the frontline of climate change because here we have stretched ecological barriers very far and we have a lot of agricultural land that is marginal. Changes in patterns are likely to be reflected in economic terms ; is it worth to grow wheat or cattle where the probability of your profit being wiped out by either drought or flood is near 30-40%? There will also be demand from the population living in regional areas for the government to provide flood proof infrastucture if extreme events recur too often. This of course is unsuntainable from an economic point of view.
The visible consequences of CC in Australia may not be in one particular catastrophic event such as we are expereincing now, but in the gradual "evacuation' of huge areas of the outback. This will go back to the indegineous people who knew how to live there, but I am afraid that they may too have lost the skills to live in such a marginal environment.

Neven

Phil, I agree with your Spanish words (muy bien, hombre), but do not forget that the warming so far has increased the water vapour content with 4%. That's a lot of water, and when it comes together in one place: not so good on ya! It's horrible what is happening in Queensland.

Australia is indeed on the front-line of AGW, what with those series of 100 year heat waves (3 in 2 years) in the south, if I'm correct (Barry Brooks wrote interesting things about that). The irony of course is that Australia resembles the US a lot when it comes to denying the obvious.

Lodger and FrankD, that's a great discussion you're having in anticipation of the melting season. There are a lot of inspiring and stimulating nuggets in there which I'm sure we'll mine in due time. I don't have to tell you to keep it up, because I know you will. Thanks.

Artful Dodger

Hi Frank, continuing through the literature I found this paper from the Polar Science Center at UWash:

Light, B., T. C. Grenfell, and D. K. Perovich (2008), Transmission and absorption of solar radiation by Arctic sea ice during the melt season, J. Geophys. Res., 113, C03023, doi:10.1029/2006JC003977.

Abstract: "The partitioning of incident solar radiation between sea ice, ocean, and atmosphere strongly affects the Arctic energy balance during summer. In addition to spectral albedo of the ice surface, transmission of solar radiation through the ice is critical for assessing heat and mass balances of sea ice... The findings of this study predict 3–10 times more solar radiation penetrating the ice cover than predicted by a current GCM (CCSM3) parameterization, depending on ice thickness, pond coverage, stage of the melt season, and specific vertical scattering coefficient profile."

There's so much goodness in this paper that i'll probably be quoting more from it here soon. Cheers!

Neven

Ladies and gentlemen, we have AD (Arctic Dipole, not Artful Dodger):

And it looks like it's going to stay that way for a few days to come, with a big, big high over the Beaufort Sea.

Kevin McKinney

Almost missed this story on CBC.CA, summarizing a modeling study by researchers at the universities of Victoria and Calgary:

http://www.cbc.ca/technology/story/2011/01/09/bc-climate-study-havoc.html#socialcomments

Particularly apropos for this site is a comment late in the story concerning the Arctic sea ice response to BAU vs. zero-emission scenarios (I'm quoting--or in other words, paraphrasing--from memory here):

"If we drop dead with emissions right now, the sea ice gets worse for 10 or 20 years, but by 2100 it's back where it has been. If we continue as we are, it's pretty much gone."

I'll see if I can't find the actual study somewhere, or at least the abstract.

FrankD

Lodger, thanks for putting up another paper I need to read....

While I think that your approach relies on assuming the pack is relatively uniform over ther medium scale, I do think it will probably give good results (because I agree with the assumption). The Petermann point was just a nit I felt like picking...
Neven's latest suggests if there is much ice left thats >1-2 metres, its probably headed into the Beaufort Sea soon, where old ice goes to die. But there's not much anyway - plots of current ice thickness show remarkable uniformity across the whole basin.

I think you missed my albedo problem though. Your equivalent area solution deals with one aspect of solar angle, but not the one I was talking about. It does deal with the issue that light at low angles is spread over a greater area, and therefore fewer W/sq m hit the surface. Got no problem with that.

The issue I did raise was different - what happens after it hits the surface. It seems to me that light falling vertically onto smooth water is almost all absorbed, while at a low angle much more light is reflected. That means that the albedo of open ocean (which you cite at 7%) cannot be a constant - all other things being equal open ocean at the equator will absorb a higher proportion of the incident light than polar water (even allowing for that equivalent area thing). See the graph here: http://en.wikipedia.org/wiki/Albedo#Water

Now I realise the ocean isn't smooth, so perhaps that makes the issue moot. All I'm suggesting is that you review whether that 0.07 albedo is correct for your purposes. For regions above 80 degrees north, you are losing 30-50% through reflectance, up to 100% at 90 degrees incidence. That's on top of any trigonometric "spreading".

But perhaps all I've really done here is show I have no idea of the properties of light (urgh, that brings back memories of a failed physics unit at high school) and should now say, "Look! A dog with a puffy tail!"

Either way, this is good - this point has clarified one thing for me: why the minimum comes so late. After equinox, the insolation in W/sq m starts dropping but for a few months at least, the dropping average albedo largely compensates, ensuring that more of the declining energy is absorbed, pumping up the heat long after it "should" have started dropping away.
(I know you knew that, I just thought I'd mention it...)

WRT to the Queensland floods, I must say I don't know why people need to find one cause. La Nina makes the ocean water off NE Australia warmer. So does global warming. The two together (and La Nina is the more important factor, by a factor of 2 or 3) make for more rain that either by itself.

Kevin McKinney

WRT the paper I linked (short-hand citation would be "Gillett et al., 2011") , the abstract is here--and you can access the full text, if you want to shell out $18:

http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1047.html

The figures are available, and worth perusing. Note that for many of them, the green line is the zero-emissions 2010 scenario, the red, the zero-emissions 2100. Very different results!

FWIW, the original press release is here:

http://www.ucalgary.ca/news/utoday/january10-2011/climatechange

It's better than--but also not that different from--the CBC story I saw first. (IMO.)

The

Daniel Bailey

Kevin:

Sent an email to Doc Snow. Re: Gillett et al

The Yooper

dorlomin

Why does ice move in the direction of the arrows and not at right angles. I thought Nansen had observed ice bergs move at right angles to the wind... (Ekman transport)

Peter Ellis

Because the arrows are not wind speed indicators. They represent the model's estimate of ice movement, rendering your question somewhat tautologous :-)

Also, I suspect the dynamics of a 100-metre berg are somewhat different to a ~1.5-metre sheet.

Artful Dodger

Frank, you've been pwned, mate. The author of the Wikipedia section you refer to is a global warming denier, Dan Pangburn. Google "Dan Pangburn debunking the Anthopogenic Global Warming Hoax"

This wiki author provides the graph as his original work, but doesn't provide the function or parameters used to plot the graph. Nor does he describe the source of observations, and goodness-of-fit estimates for his curves. This graph is not Science, it's a Hake dance, designed to look impressive but concealing the real intention.

Don't check your critical thinking skills at the door when reading Wikipedia. Recall that's where Neven got the faked 'Submarine in open water at the North Pole' he uses here as his Profile picture. We debunked that one here, too!

FrankD

Gaaargh! stupid confirmation bias.

But...but...it agreed with what I already thought, so it must be right

facepalm...

Gas Glo

Frank Re: "After equinox, the insolation in W/sq m starts dropping but for a few months at least, the dropping average albedo largely compensates, ensuring that more of the declining energy is absorbed, pumping up the heat long after it "should" have started dropping away."

Did you mean equinox or solstice? Minimum has usually been before equinox. If you meant solstice, then I think it ought to be mentioned that without albedo effects, solstice should be the highest rate of heating not the point when heating turns to cooling. Solstice would therefore be the greatest rate of volume reduction (not the minimum). If seasons were symetrical, you might expect the equinoxes to be the minimums and maximums.

Thus if you think the albedo effect delays the minimum then you might expect the date of minimum to be after the equinox but as mentioned it has more usually been before the equinox.

http://psc.apl.washington.edu/ArcticSeaiceVolume/images/PIOMAS_daily_mean.png
shows that the melting season is less than 5 months long (but still typically melts at least as much ice as freezes during more than 7 months).

If the albedo effect delays the 5 month period, then you would expect it to be later than being centred on the solstice but it doesn't seem to be noticably later than that. Perhaps this makes sense - albedo has most effect near summer solstice and cannot have much effect near autumn equinox. In short, unlike in your explanation, albedo does not seem to play much of a role in the date of the minimum.

FrankD

Gas Glo,

Yes. the second last paragraph should have read "after summer solstice"

0 for 2 - Some days, it just don't pay to get out of bed....

Kevin McKinney

I suppose one source of asymmetry in melt/freeze cycles has to do with the fact that melting occurs farther south on average, shifting the parameters of the solar forcing. Some of the shifts may not be intuitive; for example, the North Pole gets sunlight 24/7 basically from the spring equinox, though with a low angle at first, while lower latitudes that get "midnight sun" will get it later on. Contrariwise, it's "lights out" at the Pole soon after the fall equinox, while southern waters still get sun.

I don't have the tools to deal with this properly, but it seems clear that solar forcing for the Pole should be pretty symmetrical; albedo effects are limited to melt ponds and sometimes polynyas. Further south, you get open water developing, of course, which should have the general effect of introducing a sort of inertia, shifting the melt season later for those latitudes.

Kevin McKinney

Daniel, didn't get the email for some reason. Try my website, ispeakmusic.com.

Daniel Bailey

NOAA's number's are in. Good thing we had a powerful La Nina...

Is that bacon burning I smell...or me?

The Yooper

Josh

New Giss data show 2010 as a record year, 0.03 ahead of 2005.

2010 70 75 85 75 64 55 50 54 54 63 74 40 average: 65

Daniel Bailey

To amplify on my previous perspicacious (I get paid by the syllable) comment:

Source here

(sorry, Neven, the "img width" tag doesn't seem to work here)

I hear they'll be growing palm trees by Hudson Bay any time now...

And here's why they call it "up" north:

That's Polar Amplification in action!

Gonna be a fun, fun fun melt season...

The Yooper

Andrew Xnn

Maybe we should be calling it AA for Arctic Amplification since the two poles are not behaving similarly. As far as I know, the reason for this has to do with the elevation of the two poles. The South Pole is at such a high elevation that it is a lot colder, and a little bit of warming doesn't make much differance in the snow/ice albedo. On the other hand, in the North a little warming has feed back into the cryosphere big time.

Fresh fallen snow has extremely high albedo, which also covers much more of the Northern Hemisphere than the South. Anyhow, as snow melts it's albedo falls rapidly. Once melt ponds show up, they behave similarly to open water.

Of course, Arctic temperatures in December have have next nothing to do with Albedo. What we are seeing, I suspect, is just the beginning of a serious disruption of atmospheric circulation patterns. Warm air from the equatoral regions are being transported toward the Arctic. This is the only way that I can envision the arctic climate shifting towards one better suited for alligators than polar bears as was the case 50 million years ago during the eocene on Ellsemere Island.

Artful Dodger

Hi Daniel,

A study released in Aug 2010 found Tortoise and Alligator fossils on Ellesmere Island:

During the Eocene conditions on what is now Ellesmere Island were very different than they are today. Fifty million years ago summer temperatures reached over 20 degrees Celsius and winter temperatures generally stayed above freezing. The area was inhabited by alligators, tortoises, mammals and primates. Video by University of Colorado at Boulder.
Daniel Bailey

Thanks, Dodger. Nice article and vid. Hmm, at the rate we're emitting CO2, add in a bit for permafrost melt, a dash more for hydrate releases, a wee dram extra from forests turning from sinks to sources... (scratches nose, counts on fingers and toes, crosses eyes, squints)...should get to those Eocene CO2 levels of 1,000+ in about 100 years...

Sure picked a heckuva time to stop sniffing glue...

The Yooper

Artful Dodger

Daniel, you've touched on an important issue. At what point does CO2 continue to increase from feedbacks alone, even if we stop burning fossils altogether? This is the runaway greenhouse scenario that James Hansen warned about.

Daniel Bailey

@ Dodger:

Currently on Skeptical Science there's a thread on Seawater Equilibria by a Chemist, hfranzen. In his most recent comment on the thread he says:

"It therefore is not possible (at least for me) to predict what the ultimate result of a serious attempt to cut our emmissions will be, but I can say with certainty that we are likely to be disppointed because attempts to decrease the ppm by curbing our use of fossil fuels will bring about exactly what the deniers are claiming now, namely the ocean will become a major source of atmospheric CO2."

"This simple law (Henry's) tells the tale - right now the partial pressure of CO2 (the ppm) is increasing so the surface oceans are a net sink for CO2. When we try to cut back it will become a net source and our efforts will be frustrated by the large amount of CO2 in the oceans. As stated above, this frustration will be augmented by increases in the temperature of the surface ocean that will occur as a result of GW."
I'm becoming convinced that Hansen and Lovelock both were right (except, perhaps, that Lovelock didn't take the last step).


Game over, man...game over


The Yooper

Artful Dodger

I've also thought about this, without actively researching it (6 things at a time ;^). We may need to seed the Oceans with limestone to precipitate the CO2, in the same way raising mountain ranges leeches CO2 out of rainwater.

Daniel Bailey

Juggling many duties myself right now. :)

Short of calling forth the Valar to raise up a modern day Pelóri (replete with Taniquetil for the United Nations) I think the task you describe mind-boggling in scope. But then you probably have run some numbers & I'm merely a bit numb and weary.

The looming spectre of melting permafrost and the destabilizing methane traps off Siberia speak fell words in my mind, given what you portent with the Arctic sea ice & the "albedo flip" coming. Glad I'm a thousand miles from the nearest ocean.

Too much Tolkien on my mind; colours my idiom.

Thanks for the chat and the insights,

The Yooper

Heraclitus

Neven, I'm a bit out of touch here - please could you briefly explain what impact the AD is likely to have during the winter months? I'm sure this has already been discussed in depth but, well... I'm lazy.

Artful Dodger

Taniquetil? Isn't that Mt. Ruapehu in Tongariro National Park? Maybe Peter Jackson can do the movie: "An Inconvenient Extinction Event". Cheers and be well, Yooper!

FrankD

Maybe we could get Ungoliant to help us with the whole albedo thing. Geo-engineering, old schoold style...

Daniel, I'm guessing from the tag that you're from "Yooper" Michigan?What news from the Great Lakes this winter? Ice free yet?


FrankD

Dude! I just followed the NOAA link via SkS...http://www.ncdc.noaa.gov/sotc/global/2010/13

That's a pretty f***ed up collection of anomalies they've charted there.

Forget your Aliens soundbite, the movie to quote is Jaws:
"We're gonna need a bigger map..."

Neven

Neven, I'm a bit out of touch here - please could you briefly explain what impact the AD is likely to have during the winter months? I'm sure this has already been discussed in depth but, well... I'm lazy.

Heraclitus, I believe the main impact would be the transport of older ice through Fram Strait, and the transport of multi-year ice from the Canadian Archipelago to the Beaufort Sea, like we saw least year, which then has almost no chance to survive the melting season, like we saw last year.

It obviously also has an effect on extent/area increase, which is why these are relatively low at the present time (I'm sure there will be some more freezing that puts the 2011 trend somewhere between the other ones). But this could also potentially compact a lot of the ice and thus make it thicker, because an AD = lot of wind.

Yazzur

"Daniel, I'm guessing from the tag that you're from "Yooper" Michigan?What news from the Great Lakes this winter? Ice free yet?"

I'm a troll (Michigan definition - living "under", or south the Mackinac bridge,), on the little finger of Michigan, and so far, Lake Michigan is ice free, but that is not really unusual for this time of year. There has been a gradual reduction in freeze over on the larger bays over the past 20 years, with my local Grand Traverse Bay not freezing several times in the past 10 years, historically it's unusual for it to not freeze.

Who's the Hudson Bay expert here? Has it ever not frozen over?

Yazzur

Heraclitus

Thanks Neven.

Would the transport of ice through the Fram Strait not be likely to increase the extent at this time of year as it's unlikely to melt, I assume, but the open water behind it will freeze? So extent might look quite healthy, until....

I Ballantinegray1

The waters south of svalbard seem to be doing a fine and dandy job of melting the ice flushed that way! If you look at the buoy track for the 'North Pole Cam's' (deployed April 19th 2010) you'll see that the central core of 2nd/3rd year ice is now part of the Atlantic north of the U.K. (with the buoy's on their way to!!!)
http://psc.apl.washington.edu/northpole/DriftTrackMap.html

Neven

Yazzur, you're the first troll I have ever seen that announces that he is a troll in advance. ;-)

People, you may feed this troll.

Daniel Bailey

"Yooper" = Someone from Michigan's Upper Peninsula.

The protected bays have their customary adornment of ice. Those on Lake Michigan have been affected by the summer warmth and lower lake levels. This translates into a delayed formation of ice, plus ice that is more fragile and thin for the time of year. Since the bays have shallower water in general, lower water levels result in concentrating the currents in their remaining water, thinning the ice.

Ice shanties on Little Bay de Noc by Escanaba and Gladstone, a hotbed of winter fishing activity, are somewhat fewer in number and are clustered in the Northern end, away from shore where ice conditions are best. Ice has formed in most of Green Bay in the last week all the way south to the frozen tundra of Lambeau Field in the city of Green Bay (go Pack!).

As water levels of Lake Superior are controlled by the Army Corps of Engineers at the Soo Locks, this is less of an issue. Their is good ice in Munising, as always (being deeper) and in Keeweenaw Bay, by L'Anse and Baraga. Ice shanty cover (hmm, a surrogate metric for ice quality?) in Keeweenaw Bay is noticeably lagging behind normal (being mostly shallow).

The big lakes (Michigan and Superior) are still essentially ice-free, with just a fringe of shore ice at the moment. Summers record warmth of Superior, in the absence of an extended cold snap, will preclude any attempt at a full freezover. Conditions in December, while cold, were in mid-range of historical. January is trending at or above historical, so ice-boating to Canada will remain a dream... Inland lakes ice cover is good for now, unless we see warm conditions like last winter.

Of biggest concern to locals is the absence of normal snows. Like last winter, what is missing is the "trade winds" from Canada that come down from the NW causing the big snow-blower in the lake to activate & give us nightly deposits of 4" or more or fresh snow. The few system events of last winter kept snowfall totals at about 60% of historical averages. This winter is trending about the same as last. Snowmobile trails are almost impassible due to the warmth of last week (couple of days in the upper 30's, including overnight temps well-above freezing exacted a heavy toll on the trails).

To sum: Inland ice good, big lake ice so-so, snow conditions poor for snowmobiling (except in the far west end of the UP by Bessemer and Wakefield where lake effect is apparently still working, with trail bases of about 18-24" depths) but ski hills all have snow and running at capacity.

@FrankD: good one about the bigger map!

@Heraclitus: At this time of year, my understanding is that much of ice advected through the Fram is what remains of the multiyear ice. Most leads/polynas will freeze over quickly. However, as you hint at with your "until..." ice advection out the Fram is a death sentence, commuted until the spring thaw. It will then be gone, as will most of the first-year ice that formed behind it.

Since the remaining ice in the Central Arctic basin is much thinner then that of just 20 years ago, conditions like the Arctic Dipole can effect it now even in winter (think a bunch of chunks bounded together by thin ice today vs a big cohesive slab in the old days).

I wonder if an Arctic Dipole could have affected the old ice cap even in summer...

The Yooper

Yazzur

Nice summary Yooper, I was in the Keweenaw for 5 years, so I'm still bit of a Yooper.

Although not arctic ice, for those interested, here are ice maps for the Great Lakes:

http://www.glerl.noaa.gov/res/glcfs/glcfs.php?lake=l&ext=ice&type=N&hr=00

Even with warmer than normal water in the Great Lakes, our lake effect snowfall not as much as usual. Lake Michigan water level is 19" below the January average, 9" above record lows, and 53" below record high.

Yazzur

Greg Wellman

Regardless of the AGW denier status of that particular Wikipedia contributor, the reflectance of smooth water definitely behaves something close to what that graph says. Real world seawater on the other hand ... is much more complicated, and has been the subject of serious research. Here's one example: http://journals.ametsoc.org/doi/pdf/10.1175/JAS3386.1

Total spectral albedo of the ocean surface is pretty low, around 4%, for a pretty wide range of incident angles, but does pick up pretty steeply at high incidence angles. But also note:

"The albedo results are in general agreement with
theoretical results of Monte Carlo simulations by Preisendorfer
and Mobley (1986) where they noted little
dependence of albedo on wind speed for solar zenith
angles, 0 to 60°. For small solar zenith angles the albedo
increases slightly as the wind speed increases
from zero, whereas for large solar zenith angles, the
albedo decreases markedly as the wind speed picks up."

Presumably that's because choppy water gives the sunlight a lower average angle of incidence than flat water (just like a person gets more sun lying down at noon, but standing up in the later afternoon). There's also discussion and whole papers just on the effect of whitecaps.

Bfraser

I know there was some interest last year, so I thought I'd inform people that www.intrade.com has started up a Prediction Market for "Minimum Arctic ice extent for 2011 to be greater than 2007"

Evilreductionist.blogspot.com

The Yooper,

Re the CO2 issue and what happens when we reduce emissions, I do not think that the oceans will start outgassing CO2 to remain in balance until we actually start to reduce atmospheric concentrations. So it should have no effect on whether or not we can stablise atmospheric concentrations at 450 ppm or whatever. As we start pulling down CO2 from the atmosphere, that is when the ocean (assuming it is at that point in equilibrium with the atmosphere) will start to outgas. If it is not in equilibrium - if it lagging - then we will be able to reduce the concentrations without worrying about that for the time being.

Daniel Bailey

Thanks, Evilreductionist

Doctor Franzen just added a comment very germane to what you just said:

"Of course the ppm will not drop instantaneously to 350 ppm but this calculation shows the dimension of the problem faced by humankind. When we decrease our CO2 production slightly the oceans will respond by taking the gas phase content back in the direction of the starting point. In the instantaneous hypothetical about half way back. In the case of a slight decrease most of the way back. As the deniers have always said there is a very large amount of CO2 dissolved in the oceans- I just don't think they reasoned their way to the time bomb that represents for all mankind. "
Even more sobering in light of this post by Romm.


Dark times we live in. I, for one, choose to look at the positives: Freezing to death in the Arctic will be a distant memory in my childrens' lifetime...

The Yooper


Artful Dodger

Daniel, thanks for the oceanic CO2 update. BTW, no one freezes to death in the Arctic; they starve to death. I haven't seen any reports on Polar Bears in Eastern Hudson Bay. I expect that half of that population may have starved near the open water by now, perhaps 250 animals.

Yazzur, there was a good write up on the effect of the 2010 Dipole Anomaly on sea ice advection in the Jan 5, 2011 NSIDC news release.

Greg, wrong domain again (see my comment to Peter above). There are no whitecaps and almost no waves within the central ice pack, so none of those points apply.

My analysis covers the melt season from Summer solstice to min Sea Ice Area date. My method captures the In situ effect of solar insolation on SIA/SIE. The end date defines when the Sun is no longer strong enough to continue the melt.

Light et.al (2008), figure 2 shows how albedo is measured. They use 0.7 for the average albedo of sea ice. The physics of light are irrelevant to my analysis of the energy budget within the central pack.

Gas Glo

Evil Reductionist, Re "If it is not in equilibrium - if it lagging - then we will be able to reduce the concentrations without worrying about that for the time being."

I don't believe CO2 in oceans is lagging much as there is a large surface area, maybe 5 years at most. What certainly is lagging is temperature rise of the oceans. There is at least .5C committed warming in the pipeline if we immediately stop emissions over circa 30-50 years. So in the 5-30 year timeframe I believe the oceans would be a small net source of CO2 instead of a large sink. The more we try to reduce atmospheric CO2 levels the greater the ocean source would become.

FrankD

Lodger, being a bear of little brain, I still find myself confused about your analysis.

Okay, the link I posted was not to a reputable source, but that does not refute the point.
Greg posts a link to a more reputable source, and mentions in passing an interesting phenomenon in which reflectance is dependent on wind speed. You respond by saying the waves are not relevant in the pack (a point I won't dispute for now).

But Greg's reference to waves was tangential (pardon the pun). It remains that the paper that he linked to indicates that reflectance does rise steeply with incident angle in conditions relevant to your analysis.

So the point stands - using trig to compensate for the angle of incidence corrects the W/sq m striking the surface, but you also need to apply a correction for albedo of water which is dependent on solar angle, which varies over space (latitude) and time. Presumably the albedo for ice is somewhat sensitive to solar angle, but since it starts high at 0.7, it presumably changes less.

If I'm completely off beam, could you explain how? (I can usually manage up to three syllables but after that...?) What is the basis for saying water's albedo does not change materially based in angle of incident?

FrankD

I Ballantynegray1's link to the icecap buoys reminds me of the little ice island that could. Petermann Ice Island is still happily puttering its way down the coast of Baffin Island.
http://sailwx.info/shiptrack/shipposition.phtml?call=47557

It's about a third of the way along now, and should round Cape Walsingham (the easternmost cape of the island) in early April at current progress. After that, it will break for the open ocean, although its anyones guess as to exactly when that will be.

Yooper, thanks for the update on the Lakes - I find Arctic summary coverage good, but it can be difficult to get a general picture of a bit further south just by piecing together the variety of weather reports.

Daniel Bailey

Great Lakes Shipping season was just extended by 3 days, BTW (until Tuesday of next week). If the demand were there, maintenance could be done by cycling the Soo locks out of service one at a time. For lake ice is simply no longer an obstacle to shipping (Superior/Duluth is iced, requiring period ice-breaking activities, as do some of the other waterways; the big lakes are still essentially ice-free).

The Yooper

Artful Dodger

Frank: I am estimating daily solar insolation using the two known variables: First, the average angle of incidence is calculated to give an equivalent flat area that is perpendicular to the Sun. We seem to agree on this point.

Second, albedo is used to estimate absorption of this reduced amount of solar heat. Since albedo is derived from in situ measurements taken on the sea ice, it already includes the other effects like the ones you seem concerned about. They need no further treatment in this analysis.

Neven

Wayne Davidson has started a blog.

Neven

The party is over:

The AO is going to go positive (finally) in a few days from now, as cyclones are projected (by ECMWF) to fully dominate the Arctic the next 10 days. I'm guessing extent and area will shoot up as well.

Phil263

After running into "a few" problems in the Gulf of Mexico last year, it looks like BP is now having a go at mucking up the Russian Arctic. The sea ice may have a chance to recover one day if left alone, but there is no way the Earth will recover from human greed!

Artful Dodger

Hi Phil: How are you faring in Brisbane?

Phil263

Lodger: Thanks for asking.
I live on the Gold Coast (60 k South from Brisbane). Awash with rain here as well but no flooding as we are close to the ocean and storm waters get flushed out pretty fast.

Lots of damage in Brisbane as you have probably heard, even though the river did not get as high as initially predicted. John Cook who also lives in Brisbane had a recent post post on the Qld Floods. Some comments about possible links with AGW are worth a read.

Artful Dodger

"Thousands of grey seals have congregated on Pictou Island to give birth because of a lack of ice in the Northumberland Strait."
-- the Halifax ChronicleHerald

fredt34

Hi all,

The video from the "Deepsea Under the Pole" expedition is available on this french site. (so it's in French, but you'll understand the images - I don't know if an english version is available).

Incredible images from this team of divers/explorers. It shows how the ice degrades from the bottom - starting from clear, sharp edges, and finally just disagregating.

Wayne Davidson appears in the film! giving advice about the ice, just saying "it's bad, it's terribly bad" (finally the team couldn't make it to Ellesmere and were picked up).

Enjoy!

dorlomin

Did I miss this getting posted? Its already sort of discussed with talk about the changes in the heat flux coming into the Arctic, but its an interesting issue and one I fear people will use to claim the sea ice retreat is all natural.
http://scitechstory.com/2011/01/05/new-evidence-change-in-north-atlantic-currents/

Neven

Fredt34, merci for that info! Coincidentally I often translate that program - Thalassa (from French to Dutch) - so perhaps I'll get lucky and get to translate this one too.

We've discussed this project before I think, but I'm putting up a link to the Youtube flick in this post anyway because the images are so awesome. Thank again, Fred!

And thanks to you too, dorlomin, for that interesting link.

JackTaylor

Translation of page in the link provided by fredt34 | January 16, 2011 at 10:36

Google browser version 8.0.552.237 presents me with an automatic "one click" option for French to English, (but still have FireFox as default browser).

FrankD

I've been having a long rambly discussion about volume versus extent over at Patrick Lockerby's Chatterbox blog, and we got to discussing thickness (ie volume / area). I have intermittant problems posting over there, and things seem to be on the fritz again, so I thought I'd cross post here because people might be interested. I hope that's okay, Neven.

I took the monthly PIOMAS data I've posted and divided that by the area from Cryosphere Today (averaged for the month). I've superimposed some trend lines; 2nd order polynomials again which seem to give the best fit, although I'm not happy with the September curve. Still, better than linear fits, I believe.
The results are here: http://img19.imageshack.us/img19/9981/arcticicethickness.png

What leaps out at me is that historically, thickness has peaked in September, and is minimum in December. Initially surprising, but it makes sense. In September all the thin single year ice is gone, and the core of old thick ice is left, making for a high average. In December, the rapidly expanding but very thin coverage increases area far more than volume and results in a lower average thickness over the whole pack. That thickens up a bit until the melt starts again, and then again, thin ice at the fringes is the first to go and the central core of old thick ice becomes an increasing fraction of the whole, and thus average thickness rises again.

That's historically. At some point between 1998 and 2002, the summer ice volume started to fall so fast that it contributed to an overall decline in average thickness for these months. So much so that September and August, previously 1st and 2nd thickest are now 8th and 9th thickest. October, once 5th is now 11th. There is a high probability that these months will pass November and December, the historically lowest months, in the next year or two.

I attribute this dramatic change over the last ~10 years to the erosion of that core of old thick ice. The pack is more uniform in thickness than it was, and what is left in September is not substantially different from what melted away over the preceding four months. It's just what's left over when we ran out of summer. We've lost the buffer that was "protecting" extent in the Arctic Basin, and now it is just a question of enough heat in a short enough time and the core of permanent ice cover is gone.

We are now at a point where the much of the remaining ice is thin enough to be translucent, which will trigger a number of non-linear effects. On the one hand, during the early freeze up the ocean can lose heat through such thin ice, a negative feedback. OTOH, during the late thaw, the ocean can gain heat (ie albedo goes down even with ice coverage), which is a positive feedback. I would guess (and it's no more than that) that this result in more rapid melt, leading to ice free Septembers even sooner, but also a more rapid freeze, perhaps extending the lifetime of the winter pack somewhat.

Neven

I hope that's okay, Neven.

Of course. Any news from Patrick Lockerby?

Peter Ellis

FrankD: What a beautiful and lucid analysis! Could you possibly spit out some graphs showing average thickness across the yearly cycle for:

(a) historical baseline (i.e. average of 1979 through 1999)
(b) individual years from say 2006 onwards

I think that would make the point most clearly.

Lord Soth

Hi Artful Dodger.

Those seals are only a two hour drive from my place. Last year was bad for no ice in the gulf, and we lost close to 100% of the pups. The seal hunters had to go north to Labrador to hunt seals, and a vast majority did not even bother.

Around here, seals are considered the rats of the sea, as fishermen claim that they are wiping out the fish stocks. I think its over fishing, but im not getting into the politics of the matter, which is very sensitive in these parts.

With only six weeks until the ice starts to melt in the Gulf, if there is any, the ice will not be thick enough (if it even forms) to support the seals. Seals can handle one year of heavy mortaility, but when you get a string of them; the rats of the sea may be on the same list as Polar bears.

What is really scarry, is that there is no ice off of Labrador; so there is good chance of heavy mortality in the Labrador seal population.

Here is a map of current ice conditions off of Canada.

http://www.ec.gc.ca/glaces-ice/default.asp?lang=En&n=542306E5-1

Now that the NAO has gone positive, we are actually getting some real winter weather in the Martimes. Actually last night was the first time that it got down to its normal lows for this time of year in Halifax; all winter. The days have been around freezing, but the nights have only been -3 or -4 insteady of -10 and -11. Hell the lakes are have been open until two days ago; forget about ice on the ocean.

FrankD

Neven, I've not heard a peep out of Patrick since late November. His medical issues meant he tended to drop in and out without notice, but I think this is the longest he's been AWOL. :-(

@ Lord Soth: the rats of the sea may be on the same list as Polar bears.
Especially since the bears prey on the aforementioned "rats". Can't get out on the ice to hunt, and nothing to hunt even if they do.....

Peter, you mean like this?
http://img403.imageshack.us/img403/9463/arcticicethicknessrecen.png
September ice thickness is now seven (count 'em, seven!) standard deviations below the 1979-1999 mean. On this limited sample, it seems most likely that the most notable year-to-year change for 2011 will be in May-Jun-Jul thickness (with continuing, but smaller, losses in August through November). Glad you liked.

Gas Glo

>"On this limited sample, it seems most likely that the most notable year-to-year change for 2011 will be in May-Jun-Jul thickness (with continuing, but smaller, losses in August through November)."

Why do you favour flatening as opposed to changing to a sine wave with Aug Sep continuing to have largest drops?

Gas Glo

I favour Aug Sept continuing to have the largest drops. In 10 years time, I do not expect a flat line, I expect Aug to be close to zero and certainly lower than Jun.

Neven

Neven, I've not heard a peep out of Patrick since late November. His medical issues meant he tended to drop in and out without notice, but I think this is the longest he's been AWOL. :-(

Yes, I've e-mailed him a couple of times (but didn't get an answer), and asked someone over at Science 2.0 whether he knew where Patrick was (he would get back to me on that, but hasn't so far). I'm a bit worried to tell the truth. Let's just hope he's hibernating and getting in shape for the next melting season. Last thing he told me was that he was reading a lot on the history of the Arctic.

Peter Ellis

I'm with FrankD. You have to be careful with what's being graphed here: this is the average thickness of the remaining pack. As such, in that graph, 1 km^2 of 1-metre-thick ice will look exactly the same as 100000 km^2 of 1-metre-thick ice. I think the lesson is that once ice gets below an average thickness of around 1 metre, it melts out very rapidly, and thus disappears from the area value (i.e. the denominator) as well as the volume value (the numerator).

The ongoing collapse in minimum summer volume from the 1990s through to the present day has thus far manifested primarily as a loss of thickness rather than of area / extent. Therefore, the volume graph has been dropping much faster than the area / extent graphs. We may well now be at the point where that can no longer be sustained. If that is so, then the average thickness during August/September will not drop much lower, but instead, the area / extent graphs will start to collapse at the same rate as the volume graph.

Peter Ellis

Think of it like a man going bald. The hair gets thinner and thinner for a while with no immediately visible effects. At some point, he starts receding a little at the edged, but the top still looks OK - because it was thicker to start with, and he can also style it about a bit to hide the decline.

However, at some point the inevitable can be denied no longer - his scalp starts showing through across the board. First in small patches, like the area of slush we had near the Pole last summer, then in ever-widening areas until it's all gone. At the point, "average thickness of the remaining scanty locks" becomes a meaningless measure.

The Great Arctic Comb-Over is drawing to an end.

Gas Glo

>"The Great Arctic Comb-Over is drawing to an end."
Wonderful.
>"I'm with FrankD"
But please try it out and show me how it will work. For example when I try:

Year 2010:
June area 8000000
June volume 13600000
June thickness 1.7

I don't know the distribution but to get to above average figures it is going to be something like:

Area Thick Volume
250000 0.25 62500
500000 0.5 250000
750000 1 750000
2200000 1.5 3300000
3000000 2 6000000
1300000 2.5 3250000

8000000 13612500


Aug area 3540000
Aug volume 4425000
Aug thick 1.25

Distribution
Area Thick Volume
100000 0.25 25000
200000 0.5 100000
1100000 1 1100000
2140000 1.5 3210000

3540000 4435000

This 3.54m will come almost entirely from the 4.3m km^2 that is 2 or 2.5m thick.

Now take a future year where the June area is down to 6m km^2.

I would suggest distribution of
Area Thick Volume
250000 0.25 62500
500000 0.5 250000
750000 1 750000
1700000 1.5 2550000
2000000 2 4000000
800000 2.5 2000000

6000000 9612500
giving average thickness of 1.6m (just less than 2010 June thickness of 1.7m).

The area that would be left in September could be extimated as (2000000+800000)/(3000000+1300000)*3540000 = 2305116

I would suggest distribution of
Area Thick Volume
100000 0.25 25000
200000 0.5 100000
650000 1 650000
1350000 1.5 2025000

2300000 2800000
giving average thickness of 1.2m

My guesses at the distributions may be way out and the calculations resulting will be different. But can you alter them plausibly and get the Aug thickness as large as the June thickness? If you can, I would like to see how.

Gas Glo

Sorry I am an idiot. For some reason I was looking at the drom from 1.6m to 1.2m instead of the drop from 1.25m to 1.21m.

So yes I am agreeing 1.7 to 1.6m is a bigger drop in June then the 1.25 to 1.21 drop in Aug.

D'oh.

FrankD

"The Great Arctic Comb-over" .
Peter wins the internet! PMSL, but it describes perfectly how thinning has conspired to "hide the decline".

Elegantly explained, and with better reasoning than I was using. Honestly, I had got as far as noting the recent tendency for each successive year to thin out a little earlier, and that the rapidly accelerating thinning trend for July (not shown on the first graph in this series, but based on that monthly data).

You make a good point. It's plain that below some minimum average thickness the pack will simply fall apart (an issue Lodger has raised here, amongst others). 4 million sq kms of 1 millimetre thick ice is obviously ridiculous, but 4 million sq kms of 1.25 metre thickness is not, so a question is what thickness is the minimum at which a cohesive pack can exist. I'm sure there are people out there actually gathering that boring "data" stuff that people seem to find useful, but in the absence of that I'll agree with your implication that 1 - 1.2 metre might be that minimum over a large area. Below that, area crashes too.

In saying that I think the August-November period will slow down, I don't mean it will stop thinning, just that other months will catch up. That process will probably continue for a few years until the whole pack is uniform ~1 metre thick 1st and 2nd year ice. If that threshold is 1 metre or there abouts, presumably September will break through it first (probably still a few years away).

Neven

Over at the Policy Lass Steve Bloom linked to this Reuters piece on albedo:

Satellite data indicated that Arctic sea ice, glaciers, winter snow and Greenland's ice were bouncing less energy back to space from 1979 to 2008. The dwindling white sunshade exposes ground or water, both of which are darker and absorb more heat.

The study estimated that ice and snow in the Northern Hemisphere were now reflecting on average 3.3 watts per square meter of solar energy back to the upper atmosphere, a reduction of 0.45 watt per square meter since the late 1970s.

AmbiValent

The Hudson Bay finally looks frozen over... how many weeks was it behind schedule?

Andrew Xnn

While the Hudson Bay itself is almost completely frozen over, The Cryosphere Today site includes the Hudson Strait in its measure and that's still a long way from being frozen.

Max extent is about 1.25Mkm^2.
Current extent is about 0.95Mkm^2.

Right about now is when the Max extent is typically reached, so the area is still behind.

Some food for thought...

Before anybody predicts an ice free winter Arctic, keep in mind that we will have to witness an ice free winter Hudson bay long before then.

FrankD

The current area of 0.95 M sq km is, on average, reached on December 16th, so we are almost exactly five weeks behind.

Historically, the Hudson Bay / Hudson Strait area is full* for 18 weeks (on average, Jan 3rd to May 9th) and empty* for a little under 14 weeks (on average, Aug 4th to Nov 8th).

2010-11 year-to-date has seen it full* for 10 weeks (Jan 20th** - Mar 31st), and empty* for 20.5 weeks (Jul 10th - Dec 1st).

All averages are the 1979-2008 Average reported by Cryospehre Today.


* By full / empty I mean within 100,000 sq kms of maximum cover of 1.27 M sq kms or minimum cover of zero.
** In 2010 it was full from Jan 6th to Mar 31st (12 weeks). However I'm considering a rolling 12 month period which is (today) Jan 20, 2010 to Jan 19, 2011, so the first two weeks are before the beginning of the period and don't count.

Phil263

Before anybody predicts an ice free winter Arctic, keep in mind that we will have to witness an ice free winter Hudson bay long before then.
Good point Andrew and we are a long way from there!

On another topic, I found this interesting graph on SkS which shows where global warming is going. According to this graph 93.4 % goes to the oceans, while only 0.8% goes to the Arctic sea ice.
But as adelady pointed out in her comment, we have to assume that the main factor driving Arctic SI melt is the added heat in the ocean.

adelady

Peter, you just won another internet!

I don't know where or how I'll use 'The Great Arctic Comb-Over', but one day I will.

Lord Soth

Hudson bay was at least two weeks behind schedule when Environment Canada stop reporting in Mid November. Normally this is fine, as the bay is mostly frozen over by then, and is no longer a concern to shipping. I figured it got about 5-6 weeks behind in the end, however we won't know the numbers until Environment Canada comes out with its winter summary in June. I'm sure they have the numbers now, but its not on a public facing website. The port of Churchill close down on a fix date every year based on normal ice patterns, since they ship grain and need to get it out in the fall. If they only knew, they could have left it open many more weeks.

Enviornment Canada only reports on the Labrador Coast and the Gulf and St. Lawrence year round.

We have now broken all Environment Canada Records for ice in the Gulf and Newfoundland and Labrador waters.

http://ice-glaces.ec.gc.ca/prods/FECN17CWIS/20110119000000_FECN17CWIS_0005510148.txt

and

http://ice-glaces.ec.gc.ca/prods/FECN18CWIS/20110119000000_FECN18CWIS_0005510132.txt


Also due to storms, they predict no new ice will form or survive off the coast of Labrador until February. That means that we will manage to get at most two months for ice formation off of Labrador. Normally Labrador has thick first year ice. This year the ice that does form will be very thin and will melt out early; as well as with Hudson Bay. I expect a repeat of 2010 for the first part of the year for the IIJS ice graph based on this.

Here is the departure from normal graph. The solid red represent where 100% ice coverage should be.

http://ice-glaces.ec.gc.ca/prods/WIS57DPTCT/20110117180000_WIS57DPTCT_0005506634.gif


And here where we are at on Jan 20. Less than a week from the climate temperture minimun of winter. In Halifax, it falls on Feb 2 (Ground Hog Day). How Ironic.

http://www.ec.gc.ca/glaces-ice/default.asp?lang=En&n=542306E5-1

Ice has just reached the tip of Labrador. The Northern Tip !!!

I always believe that the Arctic will be free of ice in the summer. But I am totally amazed that the Labrador Coast is free of ice in the dead of winter. Words can't describe (well words for a PG rated blog), my amazment.

We are now driving over a cliff when it comes to climate change.

Kevin McKinney

"Before anybody predicts an ice free winter Arctic, keep in mind that we will have to witness an ice free winter Hudson bay long before then."

Actually, I don't think that's necessarily true. Latitude isn't the end-all and be-all determining whether or not a body of water will freeze during the winter--as I came to realize during our discussion here immediately following the minimum, in which I attempted to use Lake Superior as an analog to assess whether Gareth's projections of an ice-free winter Arctic could possibly be plausible.

Phil's comment--"as adelady pointed out in her comment, we have to assume that the main factor driving Arctic SI melt is the added heat in the ocean"--is crucial. If the Basin is getting big dollops of heat advected in on a regular basis, it may well be less prone to freeze than the Bay and environs.

But even without that factor, the climatology of the Great Lakes shows that one of the big influences on freezeup is the depth of the body of water in question. Despite the fact that Lake Erie is the most southerly of the Lakes and (I'm pretty sure) also has the highest mean air temps, it has historically been by far the most prone of the five Lakes to freeze completely. That's almost surely because its mean depth (only 62 feet, or about 19 meters) is far less than that of the others. (For context, Huron, the next shallowest, has a mean depth of about 195 feet or 59 meters.)

Most startling in this regard is the comparison of Erie to Ontario; they are adjacent, and lie nearly at the same latitudes. Yet Erie had a mean maximum ice coverage of about 87.5% (1970-1999 data) compared to only 32.5% for Ontario. (Ontario has the second-greatest mean depth, at 283 feet or 86 meters.)

(It's worth noting, though, that Erie showed the greatest decrease in mean coverage over the period of all the Lakes--from 94.5% (70s) to 77.3% (90s.)) See:

http://www.epa.gov/solec/sogl2009/4858climate.pdf

Hudson Bay is characterized by shallow and relatively fresh water (relatively speaking--its mean depth is about 330 feet or 100 meters, which is less than that of Superior); as a result it's much more capable of rapid cooling than is the Basin. I'm "handwaving," of course, but it wouldn't at all shock me if the Bay continued to show partial winter freezing after the Basin has ceased to do so.

Actually, for that matter, I don't think I'd be shocked to see some *partial* freezing in the Great Lakes, especially in the shallow bays, even after the Basin "flips"--though, as the Yooper points out and the link above shows, we've already seen some big changes in that regard.

FrankD

@Kevin McKinney
Actually, I don't think that's necessarily true.

+1.

Geography, topography and ocean currents will play a big part in what happens in the near future (as they do now, otherwise every lake in the UK would freeze over winter).

Shallow water on the coast losing heat faster than deeper basin water may lead to the central basin being free while margins are not. It will depend a lot on wind and weather, but once we have finished talking about the Great Arctic Comb-over, in a few winters we may start talking about the Polar Doughnut.

idunno

Hi everybody,

Any comments on the following...

One long-term prediction on AGW is that it could disrupt, divert or dampen the Gulf Stream, leading to colder weather in NW Europe.

I think that this might be happening. There have now been a couple of very severe winter periods here in the last two years, and this year a marked warm current of presumably GS sea water passing to the West of Greenland.

This would be evidenced by warmer weather in NE Canada, an acceleration of the ice melt, even during winter in Greenland, the ice free area of open sea off the E greenland coast, and the anomalous high pressure over Greenland.

If this is so, it is serious. The Gulf Stream, flowing as normal to the East of Greenland, should meet the ice pack somewhere near the Fram Strait, and, taking the path of least resistance, veer off further East to dissipate its heat in the open sea North of Scandinavia, without affecting the Arctic Ice much.

If some decent portion of it is going West of Greenland, then as it is forced Northwards, it has nowhere much to go except towards the Nares Strait, under the pack ice and into and under the main thick, MY ice.

In fact, looking at Topaz, there is no longer any thick 3m+ MY ice anywhere near the top of the Nares Strait. It has been steadily melting and thinnning even during this "refreezing season".

I'm sorry, I don't know how to post HTML links, so you'll have to look the TOPAZ maps up yourselves...

To use a thousand words where one picture would do...

Back in 2008, there was a great sausage of black MY ice, about 3000km x1000km, protecting the entrance to the Nares Strait and the passages between the Archipelago. By Spring of 2010, this was mostly gone, but there was still some small patches near the entrances to the straits; This winter, even during the winter, it has disappeared.


Peter Ellis

FrankD: The Polar Tonsure, surely?
.
.
.
I'll get me coat

Kevin McKinney

Welcome, idunno!

You don't need HTML to post a URL; just cut-and-paste, and the blog software will generally recognize it just fine. A (self-serving) example:

http://hubpages.com/profile/Doc+Snow

Gas Glo

>"One long-term prediction on AGW is that it could disrupt, divert or dampen the Gulf Stream, leading to colder weather in NW Europe. ... There have now been a couple of very severe winter periods."

I am definitely not any sort of expert, but wouldn't 2 severe winters be weather and not climate especially with the Gulf Stream being mainly wind driven? It surely takes more than 2 odd years to conclude prevailing winds are changing.

Also isn't the "long term 'prediction' " on Meridonal overturning circulation (MOC) which is not the gulf stream. Not sure about that being a 'prediction' either as the models take extreme (ie unrealistic forcing) to make MOC show a significant slowdown or shut down. More realistic forcings suggests a gentle slowdown that will only partly offset GW. But I am not an expert and perhaps there is some potential to shift Hadley cell and / or jet streams and thereby also affect Gulf Stream as well as MOC.

idunno, where is that coming from, though? (I don't want to be too dismissive of it if it is coming from someone who is likely to know much more than I do.)

idunno

Hi Kevin,

Sorry, should have done this better last time...

The best source for the abnormal weather patterns in the Baffin Bay area in December is a discussion between several contributors to this blog on Open Thread 3.

The latest maps showing the lack of ice cover up the Greenland coast are available from the Univerity of Bremen or Cryosphere today websites.

The continuation of the mass loss of Greenland is at:

http://www.climatechangepsychology.blogspot.com/2010/12/uh-oh-greenland-ice-loss-anomaly-2002.html

The continued loss of ice thickness in the Nares Strait entrance through the winter of 2010-11 can be viewed at:

http://topaz.nersc.no/

if you follow the link to "Check the latest forecasts".

Select Arctic, variable "hice", and any date past 27/04/2008 (is the earliest I found); but its the ones from Sep 2010 onwards that most concern me.

@Gas Glo: If ignorance really were bliss, I should by rights be far happier. You may well be right about the Gulf Stream and the MOC, I wouldn't know.

I am not really suggesting that this is climate rather than weather. I was thinking it might possibly be a pronounced factor in a prolonged change, albeit temporary, in North Atlantic weather - similar to El Nino/La Nina in the Pacific.

Anyway, to put it in a nutshell, I think there are possibly some signs that the unseasonably warm weather in NE Canada over Xmas and New Year was caused by a warm water current, flowing North.

If that warm water is still flowing North under the sea ice through the Nares Strait, it can do little else but wreak havoc.

This sort of upwelling of warmer water under the ice is a critical factor in Maslowski's understanding and model which produces an ice-free Arctic in 2016 +/- 3 years - but he only seems to refer to the phenomenon observed in the Beaufort Sea. I think it's possibly much more serious if it occurs in the N Greenland/Canadian Archipelago area - large masses of thick solid ice in this area impede the expulsion of all the rest.

Hope I'm wrong.

Neven

Welcome from me too, idunno, and thanks for explaining how to get the Topaz ice thickness images (I never managed to do it).

The PIPS ice thickness plot shows some more ice north of Greenland (mind you, there have been extensive discussions last year about the usefulness of the PIPS ice thickness images):

Here's the image for the same date in 2007:

Andyborst

idunno,

Did you read the report that came out recently that the Gulf Stream is moving northward? It has been something I have speculated on personally and it was "interesting" to see those thoughts confirmed.

http://climatesignals.org/2011/01/gulf-stream-moving-northward-with-climate-change/

Evilreductionist.blogspot.com

Just a question/observation.

With all of the warmth from the arctic ocean pumping into the atmosphere and slowing the freeze, my thinking is that this will mean that melting this season will be slower, simply due to there being less heat.

What do others think about this? While last year had some similarities to this one, there was a few hundred thousands more square kilometres of ice blocking the heat from leaving at this point in time. Is there some kind of balancing act here, with one year having more ice and, as a consequence, more spare heat for melting and another year having less ice but less spare heat for melting?

Anyway, just something I have been pondering.

Verify your Comment

Previewing your Comment

This is only a preview. Your comment has not yet been posted.

Working...
Your comment could not be posted. Error type:
Your comment has been posted. Post another comment

The letters and numbers you entered did not match the image. Please try again.

As a final step before posting your comment, enter the letters and numbers you see in the image below. This prevents automated programs from posting comments.

Having trouble reading this image? View an alternate.

Working...

Post a comment