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sorry I mean day numbers it goes from 2011221 to 2011223


IJIS prelim is -64k. Decrease holding steady...

Kevin McKinney

Yes, a hefty but not stunning decrease.


A slaughter of the ice is still possible in the East Siberian Sea. Check out what happened in August 2008...


Bob Wallace

Starting with 8/12/07 the following week averaged 43,192 and 60k was hit only four times in the remainder of the annual melt.

64k is a catch-up number. If weather predictions hold some ground should be gained over the weekend.

Seke Rob

Re Philiponfire | August 13, 2011 at 01:15

That was my point of query, sorry for not making that clear. Problem with this, leaving out day records, that if you plot this out as-is, you get the weirdest visuals unless one starts infilling the missing dates when charting. Looking at the CA Regional chart they definitely do plot along the full calendar and connect the available data points. Now that I know, applied a few changes. Having to look up the dates to put the data points in the right place is a painful way with the software I use. Cannot rely on logic like "what's the difference between yesterday and the day before". Found a similar problem with plotting ACRIM and SORCE TSI in 1 chart. SORCE in-fills missing records and puts a -9999 line in, so you know, and ACRIM just skips forward, with sometimes multi-day to a week and more missing records. My problem though. :|

k eotw

so it looks like the SEARCH August 2011 outlook is out already

Patrice Pustavrh

Neven, new Search ice outlook is finally out:

with mean at 4.6 mio km2.

Seke Rob

Personally I like the below linked view better than the one with Greenland at the low side in this phase of the melt: http://arctic.atmos.uiuc.edu/cryosphere/NEWIMAGES/arctic.seaice.color.003.png

Now, don't look at the ice... it's depressing, look at the open water, is there massive plankton bloom in the Arctic Ocean?


IJIS is now at 5827500 km^3 for August 12th, down 12,500 from the prelim. Could mean a big day for the 13th...

Seke Rob

Whenever you see for JAXA a wild number with e.g. 4 zeros at the end, it's a sign they've plugged a number to fill the hunger for... a number. Yesterday now gains 30k on 2007... 406,406 kmsq behind, on extent. Their Area chart flatly overlays 2007. Once send them a mail if they could publish their area dailies, but the reply was, that it was not in their mission. Think many would love a single source daily for Area+Extent.

Artful Dodger

Seke Rob said:

Whenever you see for JAXA a wild number...

Um, no:

6.25km x 6.25km x 149,184 cells = 5,827,500.0 km^2 sea ice extent (SIE), exactly.

Please don't invent explanations, when it is so easy to ask on this very friendly forum. There is already ample misinformation on Arctic sea ice.


Seke Rob

Point taken, but I was talking about the initial number 5840000 of prelim... those have odd numbers.


I was off-line for two days, and I just want to thank everyone for the excellent comments (these are the heart and soul of this blog).

And thanks for letting me know about SEARCH. Post will be up in a minute.

Artful Dodger

Seke Rob:

149,504 cells x 6.25km x 6.25km = 5,840,000 km^2 SIE

Hey, this is fun! Now you try one!

Seke Rob

Dodger, does nature create 149,504 or any other 'random' set of cells that exceed 15% or more sea ice that total, so they multiply to 5840000 or 6595000 or 7895000 or 7525000 or 9740000 or 9815000? Calculus is one, you had your fun, getting to know why these odd numbers come out in such high frequency is another, those 5 earlier on quick peruse since June. Are they using more raw masks or a variation of masks, depending on what larger quadrants image properties are? They note a higher error potential on their chart page, which makes roundings not improbable. It's an observation, of very low importance.



It looks to me like all the JAXA numbers are divisible by 12.5 twice meaning a 0000 end every 64 days on average.

Lodger are you sure it is 6.25km not 12.5km 'squares'?

Steve Bloom

Bob Wallace: "I'm returning to my previous idea that wider spread ice is going to suffer more bottom melt. In addition to having more room for wind/wave and sunlight to impact its edges."

I don't know about the bottom melt as such, but Rampal et al. point to the latter as a big factor. AIUI the low-conc. ice tends to grind itself into smaller and smaller pieces, which become progressively more prone to melting.

Artful Dodger

Hi Chris,

You are quite right. No two unique IJIS SIE values are closer than 156 km^2, so they must be using a 12.5 km grid. Thanks for pointing that out :^)

The native resolution of the AMSR-E sensor is 6.25 km according to NASA's AMSR-E Science webpage. Also, the Uni-Bremen Daily Graph says this in the bottom-left corner:

ASI ver. 5.2, Grid 6.25 km, Geolocation_UB

However, I see that there is also a 12.5 km gridded sea ice product for AMSR-E, so that's almost certainly the resolution they use at IJIS.


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