By Steve Goddard
August 16, 2010 offered a great opportunity to put all the Arctic data together in a coherent picture. DMI showed a large drop in extent.
http://ocean.dmi.dk/arctic/icecover.uk.php
You can see the drop between August 15 and August 16 clearly in red in the modified NSIDC map below.
So what happened? Did 300,000 km2 of ice suddenly melt?
Not exactly. There were very strong winds pushing the ice in the Beaufort and Chukchi Seas towards the pole on August 15. This compacted the ice, reducing extent while increasing the average thickness.
You can see the August 15 movement of ice in Beaufort Sea in the satellite blink map below. Note how the ice edge is tightening up and compacting.
Will this continue? Probably not. The weather forecast calls for a return to colder and calmer weather in a couple of days. Look for the DMI graph to flatten out by the weekend.
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CRS, Dr.P.H. says:
August 18, 2010 at 11:21 am
CRS sets forth a very concise definition of an honest skeptic, and like CRS I aspire to be an honest skeptic. Unlike CRS I was never an AGW believer, but I never ‘denied’ the possibility and and try not to let my skepticism reject that possibility. As a skeptic I can’t say I like Steve Goddard’s triumphantalism in this thread. yes Steve G deserves to take props for what turns out to be an accurate prediction of the 2010 melt. And yes he can delight in the fact that this is yet another data point showing that AGW alarmism is false. But, come back to us steve, this just more data, not the end. Same goes for you Phil and Andy. When does your rejection of data points disproving IPCC’s et al’s alarmist models make you guys “the deniers”. I gotta say I find comments like CRS’s more enlightening than the Steve G/Andy-Phil “yes it does no it doesn’t” debate which is just tedious. Cheers.
Meanwhile, further round the corner of the Arctic basin, the infamous Petterson (or however it’s spelt) iceberg is going nowhere, according to the satellite view of 17th. Even if the wind tried to push it out into the strait, ice is building up on the far side to get in its way. I think this berg will get well stuck with the refreeze, and it’s going to be interesting to see when it gets free again next summer.
Rich.
I’d like to see the NorthWest passage open, it’s almost there. If I was a ship merchant, I think I’d send my fleet up that way. Easy shipping New York to/from China and Japan for about 6 weeks.
Julienne says:
August 18, 2010 at 2:36 pm
R. Gates, you are correct that heat gained in the ocean during summer continues to melt ice from below even as the air temperatures start to fall below freezing. It is not only wind and compaction that contribute to continued ice loss at this time of year.
_____
It is nice to know that once in a while my arm-chair scientist’s “educated guesses”, match up well with what a Ph.D. can confirm…thanks! And BTW, I happen to see you on TV the other night on the International History Channel, maybe? You were talking about trends in Arctic ice, and I think Mark S. was interviewed on the show as well. I yelled out, “Hey, I know her!” (At least sort of) My dog picked her ears up for a second and then went back to sleep. It was the highlight of my evening…
NK
It isn’t an accurate prediction yet. If the winds keep up, extent will continue to drop.
Scott Lurndal says:
August 18, 2010 at 2:57 pm
R. Gates:
While cryostat2 _will_ be useful to determine Ice Mass more accurately, the data gathered won’t be useful without a sufficient baseline. cryostat2 will help to establish the baseline over the next few decades; only when a sufficiently long baseline is established will any conclusions about trends be useful. Trends derived from baseline data of less than two AMO/PDO cycles aren’t particularly predictive, IMO.
I don’t have a high confidence in trends derived from paleo data.
_____
In general I agree with all of this, but I think (if GCM are correct) we’ll see the trend start down and keep going. I would hope that we can get some sort of Artic Sea Ice Volume index (based on data not models) very soon after the data start to come in. As you pointed out, it will take a while to get a good baseline, but I would expect within 5 years at th maximum, we’d start to see a trend. Unfortunately, this trend will be starting during the upswing of a solar max event (no matter how weak), so we’ll need a complete solar cycle or two to guage effects of irradiance changes, and of course, longer for the effect of the PDO, etc.
My hunch is, however, that within 20 years, we’ll probably see our first ice free summer arctic, and so the rest will be academic so to speak.
R. Gates…I was wondering if the show was recently aired. I tend to get FB friend requests when I’m on TV.
I have to say though I wasn’t happy about my interview being used in that particular program. I had no idea what the program was going to be about and I certainly do not agree that the decline in Arctic sea ice is part of the 7 signs of the apocalypse.
stevengoddard says:
August 18, 2010 at 2:12 pm
R. Gates
You can see with 100% certainty from the blank map, that the loss in ice extent is due primarily to compaction.
______
I assume you meant “blink” map, but no, my reading across the entire Arctic right now is that we have a lot of ice that diverged earlier in the month and is now melting place over open water, and we also have some compaction going on, but in no way would I be willing to say with 100% certainty that the majority of the extent loss right now is from compaction alone.
The ice is compacting as it is melting but this is encouraging!
http://psc.apl.washington.edu/northpole/POPS13_atmos_recent.html
“”” stevengoddard says:
August 18, 2010 at 2:56 pm
George E. Smith
The reason I think that the ice is piling up is because PIPS shows a higher average thickness than it did a week ago. “””
Oh OK Steve, I guess I missed that part; so you do feel that in addition to just flushing out open water from between the ice there already is some pileup. Fair enough that’s all I wanted to know. Thanks Steve.
Steve,
Looking spot on so far. Needs stable weather and temps up to about Aug 28th to cook through nicely, then sit in the fridge from 1st Sept before serving with a cherry on top.
View in order:
1. http://img10.imageshack.us/img10/730/febsept15day.png
2. http://img844.imageshack.us/img844/3205/augsept15day.png
3. http://img529.imageshack.us/img529/5853/augsep7day.png
Good luck with it!
Julienne says:
August 18, 2010 at 3:34 pm
R. Gates…I was wondering if the show was recently aired. I tend to get FB friend requests when I’m on TV.
I have to say though I wasn’t happy about my interview being used in that particular program. I had no idea what the program was going to be about and I certainly do not agree that the decline in Arctic sea ice is part of the 7 signs of the apocalypse.
______
I don’t blame you for being unhappy about the use of your interview in that type of program…and I don’t normally watch “that type of program” either, but I was mindlessly channel surfing (actually a rare event for me) when I happen to come across some video of some calving glaciers. The next thing I knew, you were on the screen talking. It certainly was unethical of them to use a professional such as yourself in this manner on a sensationalist program of that type. Of course, you learned from that experience, and will always demand final option to be cut from a production if you don’t like the manner in which your soundbite is used, right? Also, did you get a chance to see a script or treatment before hand? You can also demand that if the final edited program does not follow the script or treatment to a significant extent, you have the right to have your portion taken out.
As pleased as I was to see you on TV, I was a little embarassed for you, and I’m glad to know a Ph.D doesn’t support superstitious religious notions…
Check this out – DMI temperatures above normal for the first time in months. The blast of southerly air made it all the way to the pole.
http://ocean.dmi.dk/arctic/meant80n.uk.php
Interesting that, at this point, the extent predictions are just a silly game and suddenly it is all MYI increasing over the winter. I suspect from those comments that stevengoddard no longer thinks his prediction is going to be in the ballpark … 😉
As to NSIDC changing their predictions, I have no problem with that provided they are altered consistently – in other words, provided they are using a particular model. What it means, though, is that the model is not useful from further out. As an example, the model that I am using – monthly average ice extent – is not really useful prior to June, and even the June data is not great. In any case, I am stuck with my 4.7 to 4.8. I do not think that it will go that low. So I will be wrong too.
From: Phil. on August 18, 2010 at 2:15 pm
The Canadian Ice Service report does not mention the Nares Strait.
Please have some consideration for those of us without fast internet connections and without wall-sized monitors. A link to the 4km pixel size MODIS map is preferred, I can choose a finer resolution right on the page if I desire it.
On that cloudy mosaic, you can make out that there is ice in the channels. It is thick next to the the Arctic Ocean, looks about as dense as the ocean ice. As seen on the close-ups (one, two), it’s tending to stay together and not break up, indicating (to me) a slow current flow with slow ice movement. The CIS report mentioned Multi-Year Ice influxes at Viscount Melville Sound, which are visible (see close-up one, see the ice slowly disperse), and some drifting MYI. For both half-month forecasts, MYI will be found, well, where it’s found right now.
We must have different definitions of what constitutes a “steady flow.” You should avoid doing plumbing work. When it takes a half hour to fill a toilet tank then I’d say a trickle was going into the tank, not a steady flow, whether the trickle was steady or not.
See – owe to Rich says:
August 18, 2010 at 3:13 pm
Meanwhile, further round the corner of the Arctic basin, the infamous Petterson (or however it’s spelt) iceberg is going nowhere, according to the satellite view of 17th. Even if the wind tried to push it out into the strait, ice is building up on the far side to get in its way. I think this berg will get well stuck with the refreeze, and it’s going to be interesting to see when it gets free again next summer.
It’s still edging its way out, that ice on the far side is actually pushing through at about 30km/day. Bear in mind that it’s not a flat seaice floe but is wedge shaped so it will turn in the wind.
David Gould
I can’t imagine the circumstances which would make my prediction “not in the ballpark.” But since you apparently believe that you can read minds, please entertain me further.
R. Gates says:
August 18, 2010 at 4:06 pm
Actually we never got to see the program before it goes on air, and that’s been true for most program interviews. They don’t typically even give us a copy of the interview (at least the History Channel never has). But Discovery Science was nice enough to send us the program on a DVD.
I did learn from the experience with the History Channel and I will make sure I know a lot more how an interview is to be used before agreeing to it in the future. My last interview with them for Underwater Universe was MUCH better.
phil.
You have quite an imagination. The iceberg has just been rotating, and the ice to the north is rapidly consolidating.
August 14
http://exploreourpla.net/explorer/?map=Arc&sat=ter&lvl=8&lat=81.479352&lon=-61.250332&yir=2010&dag=226
August 18
http://exploreourpla.net/explorer/?map=Arc&sat=ter&lvl=8&lat=81.479352&lon=-61.250332&yir=2010&dag=230
David Gould says:
August 18, 2010 at 4:37 pm
Interesting that, at this point, the extent predictions are just a silly game and suddenly it is all MYI increasing over the winter. I suspect from those comments that stevengoddard no longer thinks his prediction is going to be in the ballpark … 😉
As to NSIDC changing their predictions, I have no problem with that provided they are altered consistently – in other words, provided they are using a particular model. What it means, though, is that the model is not useful from further out. As an example, the model that I am using – monthly average ice extent – is not really useful prior to June, and even the June data is not great. In any case, I am stuck with my 4.7 to 4.8. I do not think that it will go that low. So I will be wrong too.
———————-
David, here is the history of the NSIDC prediction. The first prediction was based on survival rates for FYI and MYI in March (separated out as a function of ice age) and using typical survival rates of that ice through summer (rates which are likely no longer valid given thinning of the older ice, warming of the Arctic). But this method gave an idea that if the MYI was as thick as “normal” then assuming “average” atmospheric conditions, a minimum of 5.5 million sq-km was reached.
The next two predictions are done by taking the July 1st ice extent and applying average rates of decline of the ice cover throughout the remainder of the melt season. The next one starts with August 1st ice extent. All 3 predictions use statistical analysis of the data, but they use different starting points and are based on different variables (ice age survival rates and average daily ice decline rates).
stevengoddard,
I was teasing, hence the winky face – hard to convey it, I guess. 🙂
I would say that the ballpark would be, say, +/- 200,000 square kilometres or so. That is of course subjective, and a comparison between two predictions is objective, which is better.
Even there, though, I would allow some margin for error. For example, say the final result is 4.9 million. I would not be prepared to say that there was any difference between the accuracy of your prediction and the accuracy of R. Gates’ prediction. Likewise for 5.1 million. This is still giving around 200,000 or so of leeway.
Look for the DMI graph to flatten out by the weekend
SG’s predictions have been on so far in these Arctic ice posts. So look for it to happen. He must have years of experience looking at the graphs.
If there was any evidence of compaction it would be the open areas of water within the ice area becoming smaller. If anything all I can see is these areas becoming bigger, which signifies melt (although cloud in the first picture may be helping to trick my eyes), and the whole ice mass moving rapidly towards the pole, which I’m pretty sure is causing some compaction, as the proportion of open water within the ice nearer the north pole and greenland has noticeably decreased in the last week or so. But no compaction in this picture.
Also this picture shows what remains of what earlier in the season was a fairly solid spur of multi year ice. You can see how along the outer edge there are many larger floes. This compares to the younger ice to the bottom right of the photo which even though closer to the north pole is in the last stages of melt and has broken down into floes that are too small to individually pick up at this resolution.
Julienne,
Thanks for that. 🙂 Was the statistical methodology used for the 5.5 prediction a kind of test as to whether ice was normal thickness?
Dave says:
August 18, 2010 at 10:07 am
Another 70,000sk decline to yesterday.
At the present rate it will reach Steve’s predicted 5,500,000 by the middle of next week.
One morning I got up at 6:00 and it was 51F. By 12:00 noon it was 74F. Why wasn’t it 143F the next morning at 6:00???