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OldLeatherneck

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Re: IJIS/JAXA
« Reply #250 on: July 15, 2013, 07:17:47 PM »
Secondly, don't you find it rather odd that the drop was exactly 100,000??
Hi OLN,

100,000 km2 SIE is exactly 640 'cells' of 12.5 square km, which is the size used by IJIS:

http://www.google.com/search?q=100000%2F(12.5^2)

Thanks Lodger,

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Espen

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Re: IJIS/JAXA
« Reply #251 on: July 15, 2013, 08:23:38 PM »
I believe we will follow a 100,000 to 200,000 km2 drops the next few days.

Remember "Deep Purple" almost left the Bremen Stage!
« Last Edit: July 15, 2013, 08:31:15 PM by Espen »
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Bob Wallace

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Re: IJIS/JAXA
« Reply #252 on: July 15, 2013, 08:39:46 PM »
Hudson and Baffin are going to hit ~zero soon.  That removes two of the contributors to fast melt.

pikaia

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Re: IJIS/JAXA
« Reply #253 on: July 15, 2013, 09:18:54 PM »
Hudson and Baffin are going to hit ~zero soon.  That removes two of the contributors to fast melt.
On the other hand, the ice has recently pulled away from the coast on the Pacific side of the Arctic, so it has a much longer edge, giving more potential for edge-melting.

Artful Dodger

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Re: IJIS/JAXA
« Reply #254 on: July 15, 2013, 09:52:45 PM »
Hudson and Baffin are going to hit ~zero soon.  That removes two of the contributors to fast melt.
Hi Bob,

I don't think those two regions will matter much at least WRT the race with 2012 SIE. 2013 is tied for SIE in Hudson Bay, and behind about 50K in Baffin Bay:

https://sites.google.com/site/arctischepinguin/home/amsr2/grf/amsr2-extent-regional.png

Further, the Kara sea is at least 100K behind 2012 on this date, but is on track to melt out completely by about August 1st.

So as other commenters have recognized, I think it comes down to the Beaufort sea, and Central Arctic Basin. The next 8 weeks will be very interesting, the melt rate given conditions should tell us a lot about the real state of the ice.
Cheers!
Lodger

Bob Wallace

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Re: IJIS/JAXA
« Reply #255 on: July 15, 2013, 10:33:35 PM »
I've been using Wipneus' extent and area regional maps.  It seems clear to me that the 2012/2013 race for the record is all about the CAB, CA and GS.   If things continue as they are going the Beaufort will melt out as it did last year, perhaps a month+ later, but it's on track to hit zero.

Each region undergoes a period of slow melt, then rapid melt, and then perhaps a tapering off as it approaches zero.  As regions melt out that portion of rapidly melting ice is gone from the daily plunge.

As you remove the total amount of ice to be melted it becomes more difficult to maintain the absolute daily melt.

We will continue high daily melt rates if the CAB does what it did in 2012, begin a very rapid plunge about this time of year and continue to plunge for a couple of months.  Watching both area and extent it looks that 2013 might steal a march as it did in a couple of other regions.
--

Very interesting that the Greenland Sea is almost down to 2012's minimum a good month sooner.  This should allow for some significant warming of its water and keep the GS from holding much Fram transported ice until freezing resumes.


OldLeatherneck

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Re: IJIS/JAXA
« Reply #256 on: July 15, 2013, 10:42:25 PM »
In the last 21 days alone, IJIS Extent has dropped almost 2.4 Million Sq Km. Since much of the remaining ice is very vulnerable, I find it inconceivable to lose less than 4.0 Million Sq Km in the next 6-8 weeks. 2007 is fair game and 2012 is threatened.
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Espen

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Re: IJIS/JAXA
« Reply #257 on: July 16, 2013, 10:56:21 AM »
IJIS:

7,998,125 km2 (July 15, 2013)  down 70,938 km2 from previous.

280,781 km2 above 2012.

628,719 km2 below 2000s average.
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Espen

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Re: IJIS/JAXA
« Reply #258 on: July 16, 2013, 11:01:15 AM »
A small drop according to my estimates :-[
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werther

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Re: IJIS/JAXA
« Reply #259 on: July 16, 2013, 11:37:42 AM »
Hi Espen,
the number doesn't mean much. Just look at MODIS tile r04c03, CAB North of the CAA. Extended melt ponding, structure loss. Worse than '12. There was a stage then, day 190, same melt ponding. Three days later a small "leprechaun" low began the demolishing work.
I start to get excited...

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Re: IJIS/JAXA
« Reply #260 on: July 16, 2013, 11:52:34 AM »
Hi Werther,

Yes I know.
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Siffy

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Re: IJIS/JAXA
« Reply #261 on: July 16, 2013, 12:12:34 PM »
IJIS:

7,998,125 km2 (July 15, 2013)  down 70,938 km2 from previous.

280,781 km2 above 2012.

628,719 km2 below 2000s average.

not every day can be century breaks I guess :P

Espen

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Re: IJIS/JAXA
« Reply #262 on: July 17, 2013, 10:56:24 AM »
IJIS:

7,996,250 km2 (July 16, 2013) down 1,875 km2 from previous. (??????)

398,125 km2 above 2012.

555,250 km2 below 2000s average.
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Whit

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Re: IJIS/JAXA
« Reply #263 on: July 17, 2013, 11:08:05 AM »
Crumbling and fragmenting won't affect extent and area immediately, will it? It might even add to area and extent as I see it.
Is it progress if a cannibal eats with a fork?

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Re: IJIS/JAXA
« Reply #264 on: July 17, 2013, 11:19:33 AM »
Crumbling and fragmenting won't affect extent and area immediately, will it? It might even add to area and extent as I see it.

Yes, someone talked about the microphysics of ice in a bit similar fashion. We ice-affocionados should keep in mind  ice is a solid and has some habits of solids like the expansion/shrinking due the ambient temperature. Add to this the microfractures produced (at least) by surface melt and brine ejection, and air bubbles trapped within the snow turning ice, you get that ice isn't your average metallic solid, which conducts heat fast and evenly and melts pretty fast, but a solid it is and melt it will above 0 in the standard pressure. In fact, melting of ice might be compared to the melting of the ore to get the desired mineral separated, in this case water would be the product. So it's a bit of optimization problem like almost everything if one goes to the atomic level of things.

werther

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Re: IJIS/JAXA
« Reply #265 on: July 17, 2013, 01:33:27 PM »
It may very well be like Whit suggests.
through a quick check on MODIS r04c05 I saw nothing suggesting that the 'process' is interrupted, like IJIS seems to suggest when one sees it's graph.
Fast ice over there is quickly breaking up (Buor Kaya and Khatanga Gulf).
Such processes may temporarily enhance extent in these regions.

Siffy

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Re: IJIS/JAXA
« Reply #266 on: July 17, 2013, 04:12:45 PM »
IJIS:

7,996,250 km2 (July 16, 2013) down 1,875 km2 from previous. (??????)

398,125 km2 above 2012.

555,250 km2 below 2000s average.

Wow, thats a tiny drop  :o

werther

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Re: IJIS/JAXA
« Reply #267 on: July 17, 2013, 04:46:40 PM »
Must be one large, bloody important floe down getting all sensors' attention...

Whit

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Re: IJIS/JAXA
« Reply #268 on: July 17, 2013, 05:24:07 PM »
It may very well be like Whit suggests.
through a quick check on MODIS r04c05 I saw nothing suggesting that the 'process' is interrupted, like IJIS seems to suggest when one sees it's graph.
Fast ice over there is quickly breaking up (Buor Kaya and Khatanga Gulf).
Such processes may temporarily enhance extent in these regions.
It would nearly be a first according to my wife.

if I try to visualize it I just imagine a glass of water with two ice-cubes and measure area and extent. Then I smash the cubes until they're all nice and frappé-like and measure them again. Thickness has gone down, while area and extent has gone up. Still the ice should be in a more vulnerable state.

The icecubes are smaller this year it seems. It should make them disperse more and cover a larger area, thus keeping the albedo lower. My total lack of training in maths and physics leaves me totally undergunned for tackling this problem. At least, when you know very little, it's easy to learn a lot :)
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Espen

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Re: IJIS/JAXA
« Reply #269 on: July 18, 2013, 10:56:15 AM »
IJIS:

7,867,031 km2 (July 17, 2013)  down 129,219 km2 from previous.

374,531 km2 above 2012.

Still behind 2007, 2011 and 2012.
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Lennart van der Linde

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Re: IJIS/JAXA
« Reply #270 on: July 18, 2013, 12:34:02 PM »
In 2012 from today, day 200, until minimum, day 261, we lost 66k/day on average. This year we need about 72k/day on average to catch 2012 by day 261.

In 2012 the next 16 days extent lost about 66k/day on average. This year we need about 89k/day to catch 2012 in those 16 days.

In 2012 extent-loss from day 216-246 was about 88k/day and from day 246-261 about 21 k/day.

Looking at the visible state of the ice, and depending on weather of course, my guess would be that we still have about a 30-40% chance of a new record this year.

Jim Pettit

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Re: IJIS/JAXA
« Reply #271 on: July 18, 2013, 03:09:58 PM »
2012 IJIS SIE dropped an average of roughly 68.5k km2 per day from July 18 through the end of the month. To catch 2012 by the end of then, 2013 needs to drop by 93.4k km2 per day. For the month-to-date, the average daily drop has been about 115k. So, even if the current loss rate slows by 20% from now through 31 July, 2013 SIE will be virtually tied with 2012 come 1 August.

dree12

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Re: IJIS/JAXA
« Reply #272 on: July 18, 2013, 03:12:08 PM »
2012 IJIS SIE dropped an average of roughly 68.5k km2 per day from July 18 through the end of the month. To catch 2012 by the end of then, 2013 needs to drop by 93.4k km2 per day. For the month-to-date, the average daily drop has been about 115k. So, even if the current loss rate slows by 20% from now through 31 July, 2013 SIE will be virtually tied with 2012 come 1 August.

If 2013 isn't tied with 2012 by then, I'm personally throwing out any possibility of a new record. 2012 dropped precipitously from beginning of August to its minimum.

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Re: IJIS/JAXA
« Reply #273 on: July 19, 2013, 12:03:10 AM »
2012 IJIS SIE dropped an average of roughly 68.5k km2 per day from July 18 through the end of the month. To catch 2012 by the end of then, 2013 needs to drop by 93.4k km2 per day. For the month-to-date, the average daily drop has been about 115k. So, even if the current loss rate slows by 20% from now through 31 July, 2013 SIE will be virtually tied with 2012 come 1 August.

If 2013 isn't tied with 2012 by then, I'm personally throwing out any possibility of a new record. 2012 dropped precipitously from beginning of August to its minimum.

Wasn't that precipitous drop caused by the GAC2012?

Vergent

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Re: IJIS/JAXA
« Reply #274 on: July 19, 2013, 01:30:17 AM »

Wasn't that precipitous drop caused by the GAC2012?

The storm did help, but the energy that melted the ice came from albedo feedback. The ice on the pacific side broke up and spread out in June. By August, there was enough energy in the water to melt the surrounding ice several times over, much more energy than the storm could transfer.

Much the same thing is happening in the eastern CAB(central Arctic Basin) this year. The top 25-50 meters has warmed up by over 1C above the seawater melting point. See ITP-57.

Vergent

Bruce Steele

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Re: IJIS/JAXA
« Reply #275 on: July 19, 2013, 02:25:36 AM »
Vergent,  I know I should be over at the " what are the buoy's telling us" page but check out ITP 62 and 64 . The Canada Basin has some recent  surface warming also.

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Re: IJIS/JAXA
« Reply #276 on: July 19, 2013, 02:45:03 AM »
Vergent,  I know I should be over at the " what are the buoy's telling us" page but check out ITP 62 and 64 . The Canada Basin has some recent  surface warming also.

I'd say that looks like close to 2CM/day bottom melt, exclusive of any other heat inputs.
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Espen

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Re: IJIS/JAXA
« Reply #277 on: July 19, 2013, 10:56:12 AM »
IJIS:

7,669,531 km2 (July 18, 2013)  down 196,875 km2 from previous (revised).

255,468 km2 above 2012.

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Siffy

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Re: IJIS/JAXA
« Reply #278 on: July 19, 2013, 11:28:44 AM »
IJIS:

7,669,531 km2 (July 18, 2013)  down 196,875 km2 from previous (revised).

255,468 km2 above 2012.

I was about to say thats better... It kind of isn't though, I must admit I am beginning to find my fascination with the arctic ice and my struggling to find the right word here but desire to see it melt out as it would be exceptional to be rather morbid.

it's like watching a motor sport for the accidents something I would find distasteful ordinarily and yet I find my self doing the equivalent here.

either way, we look to be catching up rather rapidly.

Neven

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Re: IJIS/JAXA
« Reply #279 on: July 19, 2013, 11:32:56 AM »
Wow, that's the third biggest July daily drop in the 2005-2013 period, after having recorded the biggest drop on July 2nd this year.

I wonder what CT SIA is going to do now.
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Espen

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Re: IJIS/JAXA
« Reply #280 on: July 19, 2013, 11:37:41 AM »
From what I can see from the Bremen Map, we are still in for some big drops and the reason for that it is the poor quality of the ice.
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OldLeatherneck

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Re: IJIS/JAXA
« Reply #281 on: July 19, 2013, 01:00:55 PM »
For the remaining 12 days of July, IJIS Extent needs to drop an average of 99.6K/day to catch 2007 by the 31st of July.
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Re: IJIS/JAXA
« Reply #282 on: July 19, 2013, 01:35:50 PM »
From what I can see from the Bremen Map, we are still in for some big drops and the reason for that it is the poor quality of the ice.

Espen, are you able to format the IJIS melt numbers in a table? It would be nice to have it all the results in one table to compare the numbers more easily instead of going through each post.

Jim Pettit

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Re: IJIS/JAXA
« Reply #283 on: July 19, 2013, 02:04:23 PM »
For the remaining 12 days of July, IJIS Extent needs to drop an average of 99.6K/day to catch 2007 by the 31st of July.

True. But to catch 2012--a better analogy so far as ice condition--the required daily drop is a bit less. IJIS SIE is at 7669531 now; on July 31 last year, it was at 6499219, a difference of 1.17 million km2. There are 13 melt days left this month, for an average daily drop of a bit over 90k.

Anyway: IJIS SIE has fallen by 2.15 million km2 this month, which is I believe the largest July-to-date decrease in the record, and already substantially more than was lost in all of June. (Extent usually, though not always, drops more in July than it does than in June.)

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Re: IJIS/JAXA
« Reply #284 on: July 19, 2013, 08:14:47 PM »
-197k today ???

But before you get excited by that go to the sea ice monitor ans see where the losses are(use today's overlay on yesterday's image).

http://www.ijis.iarc.uaf.edu/cgi-bin/seaice-monitor.cgi?lang=e

The difference is mainly how much of the Aral Sea dry lake bed Jaxa is counting as ice.

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Re: IJIS/JAXA
« Reply #285 on: July 19, 2013, 08:22:10 PM »
-197k today ???

But before you get excited by that go to the sea ice monitor ans see where the losses are(use today's overlay on yesterday's image).

http://www.ijis.iarc.uaf.edu/cgi-bin/seaice-monitor.cgi?lang=e

The difference is mainly how much of the Aral Sea dry lake bed Jaxa is counting as ice.

Verg
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Do y'think maybe we or someone might be wanting to pester them about that?  Or, is it possible they are ignoring 'ice' outside of specific areas?  For them to be factoring in the Aral basin would be hideously stupid.
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Peter Ellis

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Re: IJIS/JAXA
« Reply #286 on: July 19, 2013, 08:53:35 PM »
Firstly: I doubt they're factoring in the Aral basin.  Secondly: Vergent, you're a day out with your logic.  The -197k is the change between the 17th and 18th - and if you overlay those you can see nothing much going on in the Aral.  Thirdly and much more importantly than either of the above: the IJIS graph is (I believe) still based on Windsat and not on the AMSR2 data shown in the Sea Ice Monitor.

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Re: IJIS/JAXA
« Reply #287 on: July 19, 2013, 09:15:30 PM »
For the remaining 12 days of July, IJIS Extent needs to drop an average of 99.6K/day to catch 2007 by the 31st of July.

True. But to catch 2012--a better analogy so far as ice condition--the required daily drop is a bit less. IJIS SIE is at 7669531 now; on July 31 last year, it was at 6499219, a difference of 1.17 million km2. There are 13 melt days left this month, for an average daily drop of a bit over 90k.

Anyway: IJIS SIE has fallen by 2.15 million km2 this month, which is I believe the largest July-to-date decrease in the record, and already substantially more than was lost in all of June. (Extent usually, though not always, drops more in July than it does than in June.)

Jim

The only reason I keep tracking the losses needed to catch 2007 by July 31st is that 2007 had the lowest extent value on that date, still well ahead of 2012.  My thinking is that 2013 needs to be ahead of 2012 by that time, because 2012's losses were aided an abetted by GAC-2012.  It remains to be seen if 2013 will follow the loss profile of 2007/2011 or that of 2012 during the first three weeks of August.  As an example, the average daily losses for those three years are as follows:

2007 - 65,727 Sq Km
2011 - 63,250 Sq Km
2012 - 96,703 Sq Km
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Re: IJIS/JAXA
« Reply #288 on: July 20, 2013, 10:57:11 AM »
IJIS:

7,631,719 km2 (July 19, 2013)  down 58,281 km2 from previous (revised).

287,344 km2 above 2012.
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Re: IJIS/JAXA
« Reply #289 on: July 21, 2013, 10:56:20 AM »
IJIS:

7,604,531 km2 (July 20, 2013)  down 27,188 km2 from previous.

289,500 km2 above 2012.
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Re: IJIS/JAXA
« Reply #290 on: July 22, 2013, 10:56:21 AM »
IJIS:

7,539,375 km2 (July 21, 2013) down 65,156 km2 from previous.

260,000 km2 above 2012.
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Re: IJIS/JAXA
« Reply #291 on: July 22, 2013, 06:19:28 PM »
Thirdly and much more importantly than either of the above: the IJIS graph is (I believe) still based on Windsat and not on the AMSR2 data shown in the Sea Ice Monitor.

I thought I needed to answer the last first(Most importantly).

http://www.jaxa.jp/press/2012/08/20120825_arctic_sea_e.html

This JAXA press release clearly states that SHIZUKU(AMSR2) is the source for their data. Fair mistake, they never updated the credit on their graph page.
Quote
Firstly: I doubt they're factoring in the Aral basin.
They started displaying AMSR2 images last July 24. They also started having big revisions to their initial postings on the order of 60k to 100k. On the Monitor, the concentration map would show ice on the Aral, but on the ice extent overlay, they showed the Windsat extent(identifiable by its blind spot. They were manually removing the ARAL phantom ice from the extent number so I assume they were using AMSR2 to generat the number. It is interesting that on the above, they erased the phantom ice from their concentration graphic, something they they never bothered to do on the monitor. They stopped doing these manual revisions in late August(I think they tapered them off to avoid a jump), when the validation period ended, and they started using AMSR2 generated overlays on Aug 22, 2012.
Quote
Secondly: Vergent, you're a day out with your logic.  The -197k is the change between the 17th and 18th - and if you overlay those you can see nothing much going on in the Aral.

My bad. In more ways than the one you pointed out. It is also wrong to compare one day to the previous. It takes two days to make a 95% complete scan, so doing so is to compare a lot of data to itself. I also linked to an incomplete image, the final image for the 19th, the phantom Aral ice reappeared.

Better if I had used an example that was already final. On 6/18 2013, there was a phantom melt in the Aral, and a corresponding rise in the daily loss from 90k to 130k. on the 19th the phantom ice reappeared, and the daily loss dropped to 37k.

JAXA also reads fog banks as ice on occasion.

We are coming up on the anniversary of the AMSR2 start up. From 7/24 thru 8/22 it will be invalid to compare 2013 to 2012 without subtracting 60k from 2013 corresponding to the Aral phantom ice.

Vergent


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Re: IJIS/JAXA
« Reply #292 on: July 23, 2013, 10:56:22 AM »
IJIS:

7,418,750 km2 (July 22, 2013) down 120,625 km2 from previous.

198,437 km2 above 2012.
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Espen

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Re: IJIS/JAXA
« Reply #293 on: July 23, 2013, 11:01:48 AM »
2013 will need an average drop of 95,172 km2 over the next 10 days to be on par with 2012 August 1.
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Re: IJIS/JAXA
« Reply #294 on: July 23, 2013, 11:19:24 AM »
2013 IJIS SIE has averaged -109 km2/day during the first 22 days of July. The last 10 days have averaged -92.5 km2/day.

Recall that 2012 was a leap year and has a day in hand in comparison to this year's melt season. 2013 is well on track for a new record low SIE.

I expect a dramatic collapse in the Eastern CAB, in the low concentration regions. Watch the Central Basin.  :o
Cheers!
Lodger

Espen

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Re: IJIS/JAXA
« Reply #295 on: July 23, 2013, 11:23:41 AM »
Dodger;

I expext much more the next few weeks, my guts (Bremen) tells me so! :)
Have a ice day!

Espen

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Re: IJIS/JAXA
« Reply #296 on: July 24, 2013, 10:56:21 AM »
IJIS:

7,351,719 km2 (July 23, 2013) down 67,031 km2 from previous.

219,844 km2 above 2012.
Have a ice day!

ktonine

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Re: IJIS/JAXA
« Reply #297 on: July 25, 2013, 06:23:49 AM »
Recall that 2012 was a leap year and has a day in hand in comparison to this year's melt season.

For the purposes of the melt season, clocks/calendars should be synchronized to the summer solstice (since solar insolation is the main driver).  The solstice in 2012 did fall a day earlier (June 20th), but it was at 6:09 PM.  This year it fell on June 21st and 12:04AM.

So 2012 is really only 6 hours ahead of 2013 - there's only a 6 hour difference in the solstice between any two consecutive years.  It's still more appropriate to compare this date in 2013 with the same date in 2012.  2012 will have 6 hours in hand - but to compare a date in 2013 with a day earlier in 2012 would give 2013 an 18 hour advantage.

Artful Dodger

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Re: IJIS/JAXA
« Reply #298 on: July 25, 2013, 10:19:36 AM »
Hi ktonine,

The timing of the data release from IJIS is based on UTC (coordinated universal time), not sidereal time. So we do loose a day vs. 2012 by just comparing calendar dates.  ;D

Oh BTW, welcome to the forum! Where do you teach school?  ;)
Cheers!
Lodger

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Re: IJIS/JAXA
« Reply #299 on: July 25, 2013, 10:59:43 AM »
IJIS:

7,303,281 km2 (July 24, 2013)  down 70,469 km2 from previous.

277,500 km2 above 2012.
Have a ice day!