Arctic Sea Ice : Forum

Cryosphere => Arctic sea ice => Topic started by: Paddy on July 17, 2016, 05:39:19 PM

Title: The Central Arctic Basin
Post by: Paddy on July 17, 2016, 05:39:19 PM
So I've been following the regional figures (mainly on Neven's own regional graphs page https://sites.google.com/site/arcticseaicegraphs/regional) for a while, and it looks like the CAB (Central Arctic Basin) may be melting / opening a little earlier than usual. Do we think this is a genuine effect, if so, what do we think is driving it, and do we think it's going to matter later in the season where the amount of ice left there would be the main statistic making up the total area and extent?
Title: Re: The Central Arctic Basin
Post by: icy voyeur on July 17, 2016, 06:05:13 PM
So I've been following the regional figures ...

Been noticing that too. And, especially in context of other regions that are pretty much guaranteed to melt out anyway. Will CAB ice keep dispersing into regional zones with high melt rates?  I think it's pointing to lower final numbers than many are predicting, certainly approaching the record. I worry it's an unprecedented vulnerability, subject to the next 3 weeks of weather.

Included in that weather concern, how much will dispersed ice permit wave action that will harvest warmth from below? Is just a little bit significant? No clue what the thresholds are for turbulent flow of arctic currents or how much ice re-stabilizes layers. But that's getting far far ahead of things and far outside anything I have even minor competence to address.
Title: Re: The Central Arctic Basin
Post by: Paddy on July 17, 2016, 06:12:58 PM
I was having similar thoughts, although I was a tad worried that I was being led to them by confirmation bias. EDIT: Especially considering the small scale of the CAB loss so far.
Title: Re: The Central Arctic Basin
Post by: Jim Hunt on July 17, 2016, 08:04:41 PM
So I've been following the regional figures for a while, and it looks like the CAB (Central Arctic Basin) may be melting / opening a little earlier than usual. Do we think this is a genuine effect?

Likewise!

I think it is genuine, although the situation is not as bad as some are claiming. There is a fair bit of first year ice around, which looks very vulnerable. The acid test will be how well the remaining multi-year ice holds out:

http://GreatWhiteCon.info/2016/07/has-the-ice-clearly-broken-completely-in-two-now/#Jul-16 (http://GreatWhiteCon.info/2016/07/has-the-ice-clearly-broken-completely-in-two-now/#Jul-16)
Title: Re: The Central Arctic Basin
Post by: Tor Bejnar on July 17, 2016, 10:42:40 PM
The screen shot from the current CAB area graph from the ASI Graphs page (https://14adebb0-a-62cb3a1a-s-sites.googlegroups.com/site/arctischepinguin/home/amsr2/grf/amsr2-area-regional.png?attachauth=ANoY7crcQdK70RSHmNptoC1xIN0BaQlcU7YRTO-2P5NxXzhFgcYVUBhLQNjIevos_792bD59tRaeleRMplCeDp6zSOQ_N88ORMwIGv3ZcxGFuZX6E89f2kgOFU-dJTYTn_24xV0ZldQgynWcL9iSgc6RkfzMs875hjK4Zs9qXh2iNciYRqQcTMrLU2NDdmzjtEF1LJnCt7RK6JjYhJZgbmCJ9detZwnJTpfItQhIYiyn_wMs8Vipab0zl1Ide-yr5ESY4xRLLDvB&attredirects=0) [note: click download 'here' (after clicking this link) to see image] suggests CAB has lost about 25% of what 2012 lost or about 40% of what 2015 lost.  I really don't think, however, that we know enough to gauge the impact of this year's early CAB loss.  Like you folks, I am actively wondering!

[Edit: I forgot to include the screen shot, but Nick posted it. (Thanks, Nick!)  By the way, the link works for me. Hmmm.  I corrected the bracketed note above.]
Title: Re: The Central Arctic Basin
Post by: Nick_Naylor on July 17, 2016, 11:00:09 PM
Tor, I couldn't get your link to work. Is this the graph you are referring to?
Title: Re: The Central Arctic Basin
Post by: Paddy on July 19, 2016, 08:24:06 PM
CAB area continues to drop. Looks to be a couple of weeks ahead of the nearest year now...

(https://14adebb0-a-62cb3a1a-s-sites.googlegroups.com/site/arctischepinguin/home/amsr2/grf/amsr2-area-regional.png?)
Title: Re: The Central Arctic Basin
Post by: Seumas on July 21, 2016, 10:38:41 AM
Yes, still ahead.

Title: Re: The Central Arctic Basin
Post by: Tor Bejnar on July 21, 2016, 02:35:54 PM
The early CAB ice loss is impressive.  Given the high Arctic temperature drop the DMI (http://ocean.dmi.dk/arctic/meant80n.uk.php) graph indicates, I wonder if this ice loss will continue.  Other years lost more ice in the CAB after this date than before it, and if this ratio continues, CAB ice loss will be greater than 2007's.  So for me, there remains a great big question mark!
?
I believe, Seumas, that the image you labeled "cab-2016-07-21" is actually from 2016-7-20 (although I'm sure you copied it today).  (In another ASI Forum thread, there was much todo about taking the time to accurately reference our screen shots.)
Title: Re: The Central Arctic Basin
Post by: Buddy on July 21, 2016, 03:07:56 PM
Quote
Yes, still ahead.

Look at the 2nd and 3rd graphics on the link below.  Appears that the "strategy" this year is to DIVIDE AND CONQUER when compared to 2012:

http://climatechangegraphs.blogspot.com/2012/08/arctic-antarctic-charts-volume-extent.html (http://climatechangegraphs.blogspot.com/2012/08/arctic-antarctic-charts-volume-extent.html)

Title: Re: The Central Arctic Basin
Post by: Seumas on July 21, 2016, 03:33:49 PM
I believe, Seumas, that the image you labeled "cab-2016-07-21" is actually from 2016-7-20 (although I'm sure you copied it today).
Yes, it probably is. I just grabbed the latest. Perhaps I should have named the file 'latest' and let the time of my post indicate when that was.

For such a graph, I wasn't really concerned about the exact day, more the general shape.