Please support this Forum and Neven's Blog

Author Topic: IJIS  (Read 1433004 times)

Bob Wallace

  • ASIF Upper Class
  • Posts: 1820
    • View Profile
Re: IJIS/JAXA
« Reply #50 on: May 24, 2013, 08:09:14 PM »
Indeed, we're experiencing an extremely slow start to the melting season....

2013 is bouncing along right with 2012.  2007 showed a lower extent at this point in time but started from a lower level.  Too early to worry....

ChrisReynolds

  • ASIF Upper Class
  • Posts: 1711
    • View Profile
    • Dosbat
Re: IJIS/JAXA
« Reply #51 on: May 24, 2013, 08:19:31 PM »
I disagree that we're in a slow start.

The ice edge starts to retreat within the Arctic Ocean from early June, it is only from then that conditions within the Arctic Ocean will start to be apparent in impact upon melting. And it's conditions within the Arctic Ocean that will set the scene for the September minimum.

It is far too early to conclude anything with regards the 2013 minimum in the context of area/extent.

Espen

  • ASIF Governor
  • Posts: 2992
    • View Profile
Re: IJIS/JAXA
« Reply #52 on: May 24, 2013, 09:00:04 PM »
Chris;

I completely agree with you, but I am just reporting what is going at the moment.
Have a ice day!

ChrisReynolds

  • ASIF Upper Class
  • Posts: 1711
    • View Profile
    • Dosbat
Re: IJIS/JAXA
« Reply #53 on: May 24, 2013, 09:49:44 PM »
Understood,  :)

Anyway as I don't really bother with extent I don't know what I'm doing here.  ???

Espen

  • ASIF Governor
  • Posts: 2992
    • View Profile
Re: IJIS/JAXA
« Reply #54 on: May 24, 2013, 10:04:39 PM »
Understood,  :)

Anyway as I don't really bother with extent I don't know what I'm doing here.  ???

Me too I am more concerned with volume, but those figs. are more hard to report. :-[
Have a ice day!

jdallen

  • ASIF Upper Class
  • Posts: 2415
    • View Profile
Re: IJIS/JAXA
« Reply #55 on: May 25, 2013, 04:18:19 AM »
The extent doesn't make me uncertain about my estimates for the season either.  Neither do I think we are off to a slow start, for a number of reasons, anecdotal right now, but with closer examination, may have some "teeth".

Let's start with the quality of the ice following the February/March/ongoing fracturing event.  My history with this is limited, but my perception is, in human memory, the pack has never been this small, nor this disintegrated.  For quick evidence, lets peek at the Bremen map:

http://www.iup.uni-bremen.de:8084/amsr2/arctic_AMSR2_nic.png

I've also done cross comparisons daily for the last week with other extent maps.  What I have seen is, a pack that is constantly in motion, and constantly breaking open and closing leads, across the *entire* extent of the arctic.  There's no bastion for MYI.  There is no ice showing consistently as 100% extent anywhere.  In key areas along the East Siberian Arctic and the Beaufort, there are significant areas showing up with between 10-20% open water.  There may not be large numbers of dramatic open leads, but the quality of the ice itself *prevents* that - it's too broken up.

Next, consider anecdotally the Russian North-Pole 40 evacuation.  Here's where it's located:

http://neven1.typepad.com/.a/6a0133f03a1e37970b01901c7e88c8970b-pi

Now consider this shot from Rapidfire (best guess as to approximately where I think NP-40 is):

http://lance-modis.eosdis.nasa.gov/imagery/subsets/?subset=Arctic_r05c03.2013144.terra.367

It isn't just fractured, its *granulated*.  Looking at HYCOM, that's in the middle of what should be among the most stable ice in the arctic:
(check 80N,135W - that's the approximate long/lat). 

http://www7320.nrlssc.navy.mil/hycomARC/navo/arcticictnnowcast.gif

Frankly, I don't see how you could keep large, open leads clear with all of that small trash being driven around by the wind.

Lastly, here's my kicker: consider the current ice thickness and volume.  I did some quick checking of the numbers at NP-40, the US Army has a buoy co-located with the AARI camp:

http://imb.crrel.usace.army.mil/2012G.htm

The current readings show thickness of barely 2 meters.  Once again, this is supposed to be part of the most durable part of the pack.

So, in short, I have no hope that we are better off than last year, or current readings offer any solace from the dire conclusions we've been drawing.
This space for Rent.

ChrisReynolds

  • ASIF Upper Class
  • Posts: 1711
    • View Profile
    • Dosbat

Espen

  • ASIF Governor
  • Posts: 2992
    • View Profile
Re: IJIS/JAXA
« Reply #57 on: May 25, 2013, 11:54:48 AM »
IJIS date comparison:

11,852,969 km2 (May 24, 2013) dropping only 41,719 km2 from May 23 2013. This figure is the highest measured on this date since 2003. And 180,438 km2 above the 2000s average.
« Last Edit: May 25, 2013, 01:12:15 PM by Espen »
Have a ice day!

dree12

  • ASIF Lurker
  • Posts: 24
    • View Profile
Re: IJIS/JAXA
« Reply #58 on: May 25, 2013, 01:27:21 PM »
IJIS date comparison:

11,852,969 km2 (May 24, 2013) dropping only 41,719 km2 from May 23 2013. This figure is the highest measured on this date since 2003. And 180,438 km2 above the 2000s average.

Yeah, this melt season is sure taking its time getting started. But then again, so did 2012...

Espen

  • ASIF Governor
  • Posts: 2992
    • View Profile
Re: IJIS/JAXA
« Reply #59 on: May 25, 2013, 02:19:40 PM »
With this slow decline it may merge with the 2012 level around June 1. 2012 had a hump at that time, before traveling deep south.
Have a ice day!

Shared Humanity

  • ASIF Upper Class
  • Posts: 1959
    • View Profile
Re: IJIS/JAXA
« Reply #60 on: May 25, 2013, 03:40:53 PM »
With this slow decline it may merge with the 2012 level around June 1. 2012 had a hump at that time, before traveling deep south.

SIE loss seems to be slow but SIA loss has been accelerating. Doesn't SIE loss usually lead SIA?

jdallen

  • ASIF Upper Class
  • Posts: 2415
    • View Profile
Re: IJIS/JAXA
« Reply #61 on: May 25, 2013, 11:02:18 PM »
I think the conundrum of the appearance of slowed decline in extent may have its root in the change in quality of the ice.

As Chris showed with the successive displays from Modis and Rapidfire, the coherence of the ice itself has declined massively.  There are simply more *pieces* to move around, which by nature permits a smaller area of ice to cover a larger extent.

So, the perception is, that extent is not declining as expected does not imply any decrease in melt off.  I think because the nature of the ice has changed, the extent measurements will loose their efficacy as a useful metric.  I think we need to start following SIA more closely, as that will become the more important measure.
This space for Rent.

Bob Wallace

  • ASIF Upper Class
  • Posts: 1820
    • View Profile
Re: IJIS/JAXA
« Reply #62 on: May 25, 2013, 11:42:51 PM »
But don't we have a measuring problem with area as the melt gets underway?

It's hard to distinguish between open water and melt pools, is it not?

ChrisReynolds

  • ASIF Upper Class
  • Posts: 1711
    • View Profile
    • Dosbat
Re: IJIS/JAXA
« Reply #63 on: May 26, 2013, 07:59:12 AM »
Bob,

If you think melt ponds are a problem then stick to extent.

I've recently blogged about the June CT Area crash.
http://dosbat.blogspot.co.uk/2013/05/the-ct-area-june-crash.html
It happened in 2007, 2011 and 2012. It seems likely that a large factor is melt ponding being read as open water. But the ice with more melt ponding is more likely to melt out. So this feature is still important, and it's something that would be missed using extent.

Espen

  • ASIF Governor
  • Posts: 2992
    • View Profile
Re: IJIS/JAXA
« Reply #64 on: May 26, 2013, 10:58:40 AM »
IJIS:

11,822,813 km2 (May 25, 2013)  dropping 30,156 km2 from May 24. This is 193,782 km2 above the 2000s average. But 191,437 km2 less than the 1990s average.
« Last Edit: May 26, 2013, 11:04:06 AM by Espen »
Have a ice day!

Espen

  • ASIF Governor
  • Posts: 2992
    • View Profile
Re: IJIS/JAXA
« Reply #65 on: May 27, 2013, 11:00:02 AM »
IJIS:

11,816,563 km2 (May 26, 2013) dropping 6,250 km2. This is 229,579 km2 above the 2000s average. And 164,500 km2 less than the 1990s average.
Have a ice day!

jdallen

  • ASIF Upper Class
  • Posts: 2415
    • View Profile
Re: IJIS/JAXA
« Reply #66 on: May 27, 2013, 11:13:36 AM »
Considering the differences in the quality of the ice, I'm still not convinced that greater extent will be meaningful, in so far as signifying a "bounce" this year in the melt.

I'm not sure the temperatures have really been that much lower; checking recently, I've been seeing intrusions of warm air (0-5C) over significant regions of both the east siberian arctic and the Beaufort.

I'll may be convinced if/when we reach August, and we still see significantly higher SIA across the arctic than last year.
This space for Rent.

Jim Pettit

  • Global Moderator
  • ASIF Middle Class
  • *****
  • Posts: 984
    • View Profile
Re: IJIS/JAXA
« Reply #67 on: May 27, 2013, 04:45:13 PM »
I realize there's been a recent de-emphasis on day-to-day SIA/SIE values, and for good reason. But, still, these stats caught my attention:

IJIS sea ice extent decreased by 911k km2 from 1 May through 26 May. That's the smallest extent drop for that period in at least the past 11 years, and it is, in fact, smaller than the 5/1-5/26 average drop for the decades of the 1980s, 1990s, and 2000s. (The average over the past ten years--2003 to 2102--has been 1.24 million km2, and the 1979-2012 average has been 1.26 million km2.)

(NOTE: I don't normally do this, but I cross-posted this in this thread and also in the ASI Update 1 thread in the main blog. Apologies in advance for any confusion.)

Espen

  • ASIF Governor
  • Posts: 2992
    • View Profile
Re: IJIS/JAXA
« Reply #68 on: May 27, 2013, 05:04:48 PM »
Jim;

Yes I also noticed it is a very unusual year.
Have a ice day!

Bob Wallace

  • ASIF Upper Class
  • Posts: 1820
    • View Profile
Re: IJIS/JAXA
« Reply #69 on: May 27, 2013, 06:29:37 PM »
In March of 2012 we had a period of cold weather which saw more ice formation and a delay in melting.

This year we have experienced a period of cold weather in April which has slowed melting.

Don't forget that 2012, with its period of late season cold weather, is the year with the lowest measured extent and volume.  The low amount of MYI and the state of the ice are likely more important than late winter/early spring weather.

OldLeatherneck

  • ASIF Middle Class
  • Posts: 554
    • View Profile
Re: IJIS/JAXA
« Reply #70 on: May 27, 2013, 07:51:08 PM »


2013 is only lagging 2007 by about one week and lagging 2011 by ~10 days.  This year seems t have a little more bouncing up and down, possibly due to the extreme fracturing.  It will only take 4-5 days of big melts to get 2013 back in the race.

"Share Your Knowledge.  It's a Way to Achieve Immortality."  ......the Dalai Lama

Neven

  • Administrator
  • ASIF Governor
  • *****
  • Posts: 3875
    • View Profile
    • Arctic Sea Ice Blog
Re: IJIS/JAXA
« Reply #71 on: May 27, 2013, 08:03:13 PM »
I realize there's been a recent de-emphasis on day-to-day SIA/SIE values, and for good reason. But, still, these stats caught my attention:

IJIS sea ice extent decreased by 911k km2 from 1 May through 26 May. That's the smallest extent drop for that period in at least the past 11 years, and it is, in fact, smaller than the 5/1-5/26 average drop for the decades of the 1980s, 1990s, and 2000s. (The average over the past ten years--2003 to 2102--has been 1.24 million km2, and the 1979-2012 average has been 1.26 million km2.)

(NOTE: I don't normally do this, but I cross-posted this in this thread and also in the ASI Update 1 thread in the main blog. Apologies in advance for any confusion.)


Thanks for the details, Jim, and do cross-post in this case. Amazing stats. It really is a slow start. The Arctic surprises me once more, because with all those century breaks a couple of weeks ago I thought we were in for early fireworks.
Il faut cultiver notre jardin

Espen

  • ASIF Governor
  • Posts: 2992
    • View Profile
Re: IJIS/JAXA
« Reply #72 on: May 28, 2013, 11:00:03 AM »
IJIS:

11,785,156 km2 (May 27, 2013)
31,427 km2 less than May 26.
237,183 km2 more than the 2000s average.
And 170,489 km2 less than 1990s average.
Have a ice day!

Espen

  • ASIF Governor
  • Posts: 2992
    • View Profile
Re: IJIS/JAXA
« Reply #73 on: May 29, 2013, 11:06:02 AM »
11,797,031 km2 (May 28, 2013). And the highest since 2002.
+11,875 km2 more than May 27.
287,234 km2 more than 2000s average.
and 135,344 km2 less than 1990s average.
Have a ice day!

Espen

  • ASIF Governor
  • Posts: 2992
    • View Profile
Re: IJIS/JAXA
« Reply #74 on: May 29, 2013, 02:07:34 PM »
Have a ice day!

Bob Wallace

  • ASIF Upper Class
  • Posts: 1820
    • View Profile
Re: IJIS/JAXA
« Reply #75 on: May 29, 2013, 08:33:33 PM »
We're just now coming out of a significant cold stretch of weather...



There's a large storm chewing up the ice.  It's a couple of weeks before the rapid melt season sets in.

Considering the low level of MYI and the general state of the ice I'd put more money on a new melt record than a significantly higher extent at the end of the season.

(We're sitting by Grandpa's death bed taking bets on how many more days he lasts....)
« Last Edit: May 30, 2013, 03:10:14 AM by Bob Wallace »

Artful Dodger

  • ASIF Citizen
  • Posts: 436
  • The era of procrastination is coming to a close.
    • View Profile
Re: IJIS/JAXA
« Reply #76 on: May 30, 2013, 02:53:19 AM »
We're just now coming out of a significant cold stretch of weather...
Hi Bob,

Are you able to attach images successfully to your comments? As you know, the live image you've linked to above will soon be updated, and your point will become increasingly hard to follow. By 2014, the current 80N temps won't even be shown on this image.

I'd 'up' a copy for you right now, but I've had a bad run of luck with the procedure recently. Hopefully you will fare better  ::)
Cheers!
Lodger

Bob Wallace

  • ASIF Upper Class
  • Posts: 1820
    • View Profile
Re: IJIS/JAXA
« Reply #77 on: May 30, 2013, 03:02:38 AM »
Thanks.  It hadn't occurred to me - the auto update thing.

The way I've been able to add in images is to take them first to a photo hosting site (I use Photobucket) and then link to the image in my gallery.

If it's an image off the web I do a Prtscn, copy that into a photo editor, crop away what I don't want, resize and post to Photobucket.  It's a bit of a pain so if someone has a better routine....

ETA: replaced image with a 'frozen' one.  Thanks.



« Last Edit: May 30, 2013, 03:11:05 AM by Bob Wallace »

Espen

  • ASIF Governor
  • Posts: 2992
    • View Profile
Re: IJIS/JAXA
« Reply #78 on: May 30, 2013, 11:07:23 AM »
IJIS:

11,801,094 km2 (May 29, 2013)
+ 4,063 km2 May 28,
+ 329,766 km2 more than 2000s average,
and 101,031 km2 less than 1990s average.
Have a ice day!

Artful Dodger

  • ASIF Citizen
  • Posts: 436
  • The era of procrastination is coming to a close.
    • View Profile
Re: IJIS/JAXA
« Reply #79 on: May 30, 2013, 12:32:04 PM »
ETA: replaced image with a 'frozen' one.
Hi Bob,

Thanks! This'll be important years from now in Nuremberg and The Hague.  ;)
Cheers!
Lodger

wanderer

  • ASIF Citizen
  • Posts: 156
    • View Profile
Re: IJIS/JAXA
« Reply #80 on: May 30, 2013, 01:55:12 PM »
Something is rotten in the state of "ijis extent"!

It might be the sea ice...

I guess it's the calm before the storm!


Bob Wallace

  • ASIF Upper Class
  • Posts: 1820
    • View Profile
Re: IJIS/JAXA
« Reply #81 on: May 30, 2013, 06:07:46 PM »
The Bremen extent measurement seems to be showing 2013 roughly tied with 2012.

http://www.iup.uni-bremen.de:8084/ssmis/extent_n_running_mean_F17_regular.png

At this point the horses are just getting into the gates and the jockeys are trying to get them settled down.  It's too early to figure out who will be ahead as we head into the finish line.

I've got modest money on horse number thirteen, Rotten Ice.  If he gets a good start out of the gates then it could be a blow out....

deep octopus

  • ASIF Middle Class
  • Posts: 548
    • View Profile
Re: IJIS/JAXA
« Reply #82 on: May 30, 2013, 10:11:08 PM »
NSIDC extent also shows 2013 pinching with 2012.
http://nsidc.org/data/seaice_index/images/daily_images/N_stddev_timeseries.png

The Charctic (oh ho ho) Interactive Graph from NSIDC also exemplifies the closeness here, when the y-scale is drawn to zero:
http://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/

It's fair to say that 2012 was falling apart by the second week of June, in spite of a similarly slow May. In 2007, the crash was very extreme in the first week of July, when it lost 1 million km^2 in six days. My guess is we haven't even had the slightest whiff of what is possible this year.

Espen

  • ASIF Governor
  • Posts: 2992
    • View Profile
Re: IJIS/JAXA
« Reply #83 on: May 31, 2013, 10:58:16 AM »
IJIS:

11,769,844 km2 (May 30, 2013)
31,250 km2 less than May 29

326,141 km2 more than 2000s average
and 94,531 km2 less than 1990s average

Have a ice day!

Shared Humanity

  • ASIF Upper Class
  • Posts: 1959
    • View Profile
Re: IJIS/JAXA
« Reply #84 on: May 31, 2013, 03:37:43 PM »
Should we expect some denialist to suggest a SIE minimum is approaching?  :o

http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm

Espen

  • ASIF Governor
  • Posts: 2992
    • View Profile
Re: IJIS/JAXA
« Reply #85 on: May 31, 2013, 03:58:27 PM »
Yes that curve is heading in the wrong direction this time of the year ???
Have a ice day!

OldLeatherneck

  • ASIF Middle Class
  • Posts: 554
    • View Profile
Re: IJIS/JAXA
« Reply #86 on: May 31, 2013, 04:07:24 PM »
Should we expect some denialist to suggest a SIE minimum is approaching?  :o

http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm


Should the denialists claim that the arctic sea ice is recovering in the middle of the melt season, they will be greatly disappointed when they see the open water in the middle of the CAB within the next week or two.
"Share Your Knowledge.  It's a Way to Achieve Immortality."  ......the Dalai Lama

Espen

  • ASIF Governor
  • Posts: 2992
    • View Profile
Re: IJIS/JAXA
« Reply #87 on: June 01, 2013, 11:01:07 AM »
IJIS:

11,677,813 km2 (May 31, 2013) down 92,031 km2 from May 30.

And 258.032 km2 more than 2000s average.

But 149,312 km2 less than 1990s average.

Maybe the ice realized it is summer now?
Have a ice day!

icebgone

  • ASIF Lurker
  • Posts: 58
    • View Profile
Re: IJIS/JAXA
« Reply #88 on: June 02, 2013, 12:02:33 AM »
I'm waiting to declare summer melting in full swing when I see the first triple century melt day.

Espen

  • ASIF Governor
  • Posts: 2992
    • View Profile
Re: IJIS/JAXA
« Reply #89 on: June 02, 2013, 10:58:20 AM »
IJIS:

11,645,781 km2 (June 1, 2013) down 32,032 km2 from May 31.
Have a ice day!

crandles

  • ASIF Upper Class
  • Posts: 1704
    • View Profile
Re: IJIS/JAXA
« Reply #90 on: June 02, 2013, 11:18:37 AM »
Any thoughts on this slow decline of extent being due to Ekman pumping?

Is Ekman pumping likely to have greater dispersive effect if the pack is more broken up than usual for the time of year?

sofouuk

  • ASIF Lurker
  • Posts: 82
    • View Profile
Re: IJIS/JAXA
« Reply #91 on: June 02, 2013, 12:11:57 PM »
not sure about the importance of the pumping, but it's intuitive that a thin fragmented pack will tend to splay out more before melting more quickly. We imagined that was happening last spring in April, but if thats the cause of the high extent now (rather than a genuinely slow start to the melt due to lower than average temperatures) it's another bad sign. At least it allows us to predict an anomalously high spring extent for future years, not that the denialists will allow that to discourage them, of course

Espen

  • ASIF Governor
  • Posts: 2992
    • View Profile
Re: IJIS/JAXA
« Reply #92 on: June 02, 2013, 01:32:35 PM »
Much of the "delay" in the melt of arctic sea ice may be due to the fact the sea ice is spread out over a larger area because of the high fragmentation , the same happened i 2012, and the real melt started in the second week of June that year.
« Last Edit: June 02, 2013, 01:44:19 PM by Espen »
Have a ice day!

SATire

  • ASIF Citizen
  • Posts: 462
    • View Profile
Re: IJIS/JAXA
« Reply #93 on: June 02, 2013, 01:38:32 PM »
Any thoughts on this slow decline of extent being due to Ekman pumping?

Is Ekman pumping likely to have greater dispersive effect if the pack is more broken up than usual for the time of year?
I don't think so - SIA in a very big circle (2.7 Mio. sq km) in the Basin only droped 40-50k since 20th may due to the storm. So if there is ice diverging out of the Basin it is not very much. I think, the SIA-loss due to the storm is either still to become visible for the satellites or can be neglected at all. We will see that in a week or so.

Bob Wallace

  • ASIF Upper Class
  • Posts: 1820
    • View Profile
Re: IJIS/JAXA
« Reply #94 on: June 02, 2013, 06:43:48 PM »
The temperature north of 80 continues to be colder than the 1958 to 2002 average.

http://ocean.dmi.dk/arctic/meant80n.uk.php

The big tell here is going to be the end of May PIOMAS volume.  If volume is down then it's likely that bottom melt has been thinning the ice and setting up rapid June/July melting and extent drops.  If volume is holding then this may not be a record low year.

Espen

  • ASIF Governor
  • Posts: 2992
    • View Profile
Re: IJIS/JAXA
« Reply #95 on: June 03, 2013, 10:57:21 AM »
IJIS:

11,633,281 km2 (June 2, 2013) down 12,500 km2 from June 1!?
Have a ice day!

Siffy

  • ASIF Citizen
  • Posts: 179
    • View Profile
Re: IJIS/JAXA
« Reply #96 on: June 03, 2013, 11:17:15 AM »
IJIS:

11,633,281 km2 (June 2, 2013) down 12,500 km2 from June 1!?

Is this unexpected?

Are you able to post the data for the last two to three years +- a few days either way to compare typical loss?

dree12

  • ASIF Lurker
  • Posts: 24
    • View Profile
Re: IJIS/JAXA
« Reply #97 on: June 03, 2013, 02:09:50 PM »
IJIS:

11,633,281 km2 (June 2, 2013) down 12,500 km2 from June 1!?

Is this unexpected?

Are you able to post the data for the last two to three years +- a few days either way to compare typical loss?

Because of daily variation, this is not an unusual event. However, it combines with unusually slow decline recently to further distance the 2013 line from other recent years.

Effectively, this alone is not unusual. However, it is yet another day of slow growth that makes the past few weeks highly unusual.

OldLeatherneck

  • ASIF Middle Class
  • Posts: 554
    • View Profile
Re: IJIS/JAXA
« Reply #98 on: June 03, 2013, 02:36:54 PM »
Is this unexpected?

Are you able to post the data for the last two to three years +- a few days either way to compare typical loss?


The below table is the IJIS Extent for dates 27 May - 2 Jun for years 2003 - 2013.  I've highlighted as follows:

RED:  Lowest Extent for that Day
GREEN: Highest Extent for that Day
YELLOW: Median Extent for that Day




"Share Your Knowledge.  It's a Way to Achieve Immortality."  ......the Dalai Lama

Bob Wallace

  • ASIF Upper Class
  • Posts: 1820
    • View Profile
Re: IJIS/JAXA
« Reply #99 on: June 03, 2013, 06:11:44 PM »
I'm loosing the point here. 

Are we concerned by the slow melting as shown by IJIS/JAXA or the fact that IJIS/JAXA is showing a melt rate different than NSIDC and Bremen which show 2012 and 2013 almost the same?