Support the Arctic Sea Ice Forum and Blog

Author Topic: 2014 sea ice area and extent data  (Read 521743 times)

Neven

  • Administrator
  • First-year ice
  • Posts: 7616
    • View Profile
    • Arctic Sea Ice Blog
  • Liked: 982
  • Likes Given: 501
Re: 2014 sea ice area and extent data
« Reply #150 on: March 10, 2014, 10:44:18 PM »
I also like to let you guys (and gals) know that I've updated the Concentration Maps page on the ASIG, which allows a quick way of comparing the current Uni Bremen sea ice concentration map with those of previous years in the 2007-2014 period. See for instance March 13th.
Il faut comparer, comparer, comparer, et cultiver notre jardin

pearscot

  • Frazil ice
  • Posts: 248
    • View Profile
  • Liked: 111
  • Likes Given: 43
Re: 2014 sea ice area and extent data
« Reply #151 on: March 11, 2014, 02:42:20 AM »
You know those carts far more than I do.  In your opinion, what are some interesting changes or items to note in comparison to other years?  In some ways, 2014 does look a bit like 2012 as far as some thinner areas in the central polar region.  It's also interesting to note how thin the ice is going into the pole on one said.  Quite interesting Indeed.
pls!

jdallen

  • Young ice
  • Posts: 3127
    • View Profile
  • Liked: 305
  • Likes Given: 189
Re: 2014 sea ice area and extent data
« Reply #152 on: March 11, 2014, 04:18:38 AM »
You know those carts far more than I do.  In your opinion, what are some interesting changes or items to note in comparison to other years?  In some ways, 2014 does look a bit like 2012 as far as some thinner areas in the central polar region.  It's also interesting to note how thin the ice is going into the pole on one said.  Quite interesting Indeed.

Yup, like 2012, only worse.
This space for Rent.

Neven

  • Administrator
  • First-year ice
  • Posts: 7616
    • View Profile
    • Arctic Sea Ice Blog
  • Liked: 982
  • Likes Given: 501
Re: 2014 sea ice area and extent data
« Reply #153 on: March 11, 2014, 07:59:16 AM »
You know those carts far more than I do.  In your opinion, what are some interesting changes or items to note in comparison to other years?  In some ways, 2014 does look a bit like 2012 as far as some thinner areas in the central polar region.  It's also interesting to note how thin the ice is going into the pole on one said.  Quite interesting Indeed.

Yup, like 2012, only worse.

I have to agree that on the surface it looks like 2012, but worse (Kara Sea being the most prominent exception). This doesn't mean that this melting season will be worse as well, as this depends on more circumstances, for instance the amount and distribution of multi-year ice.
Il faut comparer, comparer, comparer, et cultiver notre jardin

werther

  • Grease ice
  • Posts: 730
    • View Profile
  • Liked: 12
  • Likes Given: 0
Re: 2014 sea ice area and extent data
« Reply #154 on: March 11, 2014, 10:19:06 AM »
Hi Neven,

From the perspective based on our collective experience through your blog, I guess  you’re right.
Weather during the melt season does have a profound relevance.

But my ‘first impression’ based on ‘winter power’ suggests me this was one hell of a bad starter for the next melt season.
This is 1000Mb temp anomaly 1 Feb-8 Mar:



I can’t recall having seen anything like this. Same period 2010 comes close to some extent, with positive anomaly concentrated around Hudson Bay-Labrador.
Where last winter produced a ’ring of cold’ circling the Pole and producing a late boost to peripheral FYI, there’s no strenghtening at all now.

Every late winters’ day brings more support for ‘winter power’ 1Oct-31Mar to become the ‘hottest’ Arctic winter ever since the start of satellite data collection.
The only break might be in the forecast build-up of a high on the axis Greenland-Beaufort Sea (ECMWF; most pronounced 18-19 Mar).

BornFromTheVoid

  • Nilas ice
  • Posts: 1002
    • View Profile
  • Liked: 32
  • Likes Given: 44
Re: 2014 sea ice area and extent data
« Reply #155 on: March 11, 2014, 12:08:31 PM »
I think this chart says a lot.
It's the Dec-Feb average of this year, minus the Dec-Feb average of 2007-2013. The difference, even compared to those very mild years, is incredible.


Jim Pettit

  • Global Moderator
  • Nilas ice
  • Posts: 1175
    • View Profile
  • Liked: 40
  • Likes Given: 11
Re: 2014 sea ice area and extent data
« Reply #156 on: March 11, 2014, 12:11:46 PM »
IJIS Extent:

14,025,724 km2 (10 March, 2014)
(2014 maximum to-date: 14,255,140 km2 06 March, 2014)

Up 9,798 km2 from previous day.
Down 101,169 km2 over past seven days (daily average: -14,453 km2)
Up 352 km2 for the month of March (daily average: 35 km2)

636,183 km2 below 2000s average for this date.
304,733 km2 below 2010s average for this date.
484,698 km2 below 2012 value for this date.

Lowest ever for the date.
Second consecutive day, and the 21st this year, in first place.
Third consecutive day, and the 37th this year, among the lowest three years on record.

Fourth lowest March-to-date average on record (behind 2006, 2011, and 2007).
« Last Edit: March 12, 2014, 11:44:39 AM by Jim Pettit »

deep octopus

  • Grease ice
  • Posts: 559
    • View Profile
  • Liked: 8
  • Likes Given: 17
Re: 2014 sea ice area and extent data
« Reply #157 on: March 11, 2014, 01:42:04 PM »
Nice work BFTV. That is very revealing. I've also noticed that every day of 2014 has been warmer than average on DMI's temperature readings north of 80 N. I don't know of any other examples of this in the past data, so who knows what that means.

It's moreover fascinating to me that the extent data of present is about where 2013 was in early April, and where 2012 was in mid-April. That would be a massive head start if the trend can hold into spring. I also am interested in the fact that snow extent in Europe and parts of Asia are below average on Rutgers Snow Lab.
« Last Edit: March 11, 2014, 03:07:56 PM by deep octopus »

Pmt111500

  • Nilas ice
  • Posts: 2119
  • Yes, I do not always bicycle
    • View Profile
  • Liked: 174
  • Likes Given: 96
Re: 2014 sea ice area and extent data
« Reply #158 on: March 11, 2014, 04:43:53 PM »
as the daily changes can be quite huge and see-saw back and forth I've been using various averages to try to find trends in the CT SIA dataset, still  currently using the 5-day weighted average (occasionally this is noted as '5 day smooth'). Here's what has happened with some of them from the beginning of the year. It appears that 13- and 15-day running means follow the weighted averages quite well, better than most others. This is of course near half a lunar cycle, so there might have been some celestial influence here (or pure chance). I'd just need to figure out how to take 14,75 day running mean (this isn't as easy as one might think) to see if this applies in all the dataset, even though last year I couldn't find correlation, sync might have been out of phase on the areas of data I checked. I think I'll use the 29-day system to call the maximum, might have happened allready but as it lags 15 days, this has to wait.
Cooling the outside by heat pump.

crandles

  • Young ice
  • Posts: 2678
    • View Profile
  • Liked: 149
  • Likes Given: 53
Re: 2014 sea ice area and extent data
« Reply #159 on: March 11, 2014, 05:02:27 PM »
CT Area:
2014.1808  -1.0661002  13.0419340  14.1080341
2014.1836  -1.1562057  12.9566565  14.1128626

85k 1 day fall
187k below lowest for this day!
125k below the peak so far ( 2014.1453  -0.9380707  13.0817108  14.0197811)

Is anyone calculating what proportion of years fail to gain 125k from this date?
« Last Edit: March 11, 2014, 05:08:16 PM by crandles »

jdallen

  • Young ice
  • Posts: 3127
    • View Profile
  • Liked: 305
  • Likes Given: 189
Re: 2014 sea ice area and extent data
« Reply #160 on: March 11, 2014, 05:23:02 PM »
You know those carts far more than I do.  In your opinion, what are some interesting changes or items to note in comparison to other years?  In some ways, 2014 does look a bit like 2012 as far as some thinner areas in the central polar region.  It's also interesting to note how thin the ice is going into the pole on one said.  Quite interesting Indeed.

Yup, like 2012, only worse.

I have to agree that on the surface it looks like 2012, but worse (Kara Sea being the most prominent exception). This doesn't mean that this melting season will be worse as well, as this depends on more circumstances, for instance the amount and distribution of multi-year ice.

Oh, absolutely agree, Neven.   This is an "all else being equal" rumination.  Weather will determine if we get 2013, or 2012 on steroids.

Regarding MYI,  the distribution has become quite asymmetric, with the "bastion" along the CAA getting quite thin, and the larger share of thicker ice driven into the Beaufort and Chukuchi. 

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


This is rather not optimal for preservation. Note also how thin most of the ice is in peripheral seas.  Even with anemic melt conditions, those will probably translate into an early extent nosedive.  I think we could pass 2012 with even "average" melt season conditions.   If I wanted conditions optimal for a serious decline, it would look a lot like this.  Now we get to fidget while we wait...
« Last Edit: March 11, 2014, 05:35:23 PM by jdallen »
This space for Rent.

wanderer

  • Frazil ice
  • Posts: 156
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: 2014 sea ice area and extent data
« Reply #161 on: March 11, 2014, 05:55:16 PM »
Everything is possible - especially after last year - and... speaking of area:
http://arctic.atmos.uiuc.edu/cryosphere/arctic.sea.ice.interactive.html
2013 was a long time very close to 2012 and even slightly ahead until day 130- almost the same around day 150 and still not too far away around day 200 - but I personally would bet that 2014 will beat 2013 (because of winter warmth), everything else is still uncertain!

wili

  • Young ice
  • Posts: 3037
    • View Profile
  • Liked: 489
  • Likes Given: 344
Re: 2014 sea ice area and extent data
« Reply #162 on: March 11, 2014, 06:17:56 PM »
 Unless a good portion of the anomalous warmth is from heat escaping from the sea water through leads?
"A force de chercher de bonnes raisons, on en trouve; on les dit; et après on y tient, non pas tant parce qu'elles sont bonnes que pour ne pas se démentir." Choderlos de Laclos "You struggle to come up with some valid reasons, then cling to them, not because they're good, but just to not back down."

jdallen

  • Young ice
  • Posts: 3127
    • View Profile
  • Liked: 305
  • Likes Given: 189
Re: 2014 sea ice area and extent data
« Reply #163 on: March 11, 2014, 07:43:32 PM »
Unless a good portion of the anomalous warmth is from heat escaping from the sea water through leads?
Even with leads, the loss will have been buffered by anomalously high temperatures driven by inflow of warmer air from lower latitudes.  Most of the region has at minimum been 5C above average.  It strikes me that we may be seeing that reflected in the thickness and distribution of the ice.  Ice preserved from last year thickened little.  Much of the area just North of Siberia looks to be no more than 2 meters thick.

As I said, if I wanted to construct optimal ice conditions for melt, it would look a lot like this.
This space for Rent.

ChrisReynolds

  • Nilas ice
  • Posts: 1714
    • View Profile
    • Dosbat
  • Liked: 2
  • Likes Given: 0
Re: 2014 sea ice area and extent data
« Reply #164 on: March 11, 2014, 08:16:04 PM »
Wili,

I don't think it is thin ice or leads causing warming. In my most recent blog post I did my temperature analysis at 500mb, high enough to avoid the worst of the low level warming caused by thin ice.

Here's a cross section of late winter warming due to thinner ice.


500mb is well above that, and here's February 2014 difference from 2013.

That's very similar to BFTV's posting. The warming is due to the Pacific North American Pattern.
http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/pna.shtml

It's been largely negative through February and the ensemble members are closely grouped suggesting a further negative excursion shortly.


I'm seriously pondering calling it and blogging a 'maximum' post. The problem is I suspect that whatever forecasts say, the moment I click 'post' howling -20degC winds will simultaneously burst out of Siberia and into Barents, Okhotsk & Bering.  :o

Jim Hunt

  • Young ice
  • Posts: 4519
  • Stay Home, Save Lives
    • View Profile
    • The Arctic sea ice Great White Con
  • Liked: 431
  • Likes Given: 30
Re: 2014 sea ice area and extent data
« Reply #165 on: March 11, 2014, 08:26:35 PM »
I'm seriously pondering calling it and blogging a 'maximum' post. The problem is I suspect that whatever forecasts say, the moment I click 'post' howling -20degC winds will simultaneously burst out of Siberia and into Barents, Okhotsk & Bering.  :o

I clicked "Post" already Chris, but my reputation is already in tatters so what the hell!

I proudly present "The 2014 Melting Season"

Reality is merely an illusion, albeit a very persistent one - Albert Einstein

BornFromTheVoid

  • Nilas ice
  • Posts: 1002
    • View Profile
  • Liked: 32
  • Likes Given: 44
Re: 2014 sea ice area and extent data
« Reply #166 on: March 11, 2014, 08:33:37 PM »
Cold northerly air streams blasting into Barents and Bering, just a day away!





Whether it's enough now with the sun rising remains to be seen, but I personally wouldn't call the maximum yet. You only have to go back to 2003 (NSIDC extent) to see a 300k increase between the 9th (15,289,100km2) and the maximum on the 20th (15,586,800km2).

Shared Humanity

  • Guest
Re: 2014 sea ice area and extent data
« Reply #167 on: March 11, 2014, 09:09:45 PM »
Even with brutal cold washing over the Bering and Barents, isn't it too late in the season for this to cause any more than a thin skin of ice which could melt in just a few days?

lanevn

  • New ice
  • Posts: 91
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: 2014 sea ice area and extent data
« Reply #168 on: March 11, 2014, 09:22:13 PM »
But it can be enough to waste record low maximum ).

deep octopus

  • Grease ice
  • Posts: 559
    • View Profile
  • Liked: 8
  • Likes Given: 17
Re: 2014 sea ice area and extent data
« Reply #169 on: March 11, 2014, 09:30:55 PM »
Also interesting is that CCI's (also from GFS models) surface temperature anomalies, despite temperatures at the 850 hPa level, assert an overall warmer than average Arctic through the 18th. The coolest sections appear to be on Bering. Okhotsk being warmer than average should balance that. Kara Sea to be much warmer than average through the week as well? Having a hard time reconciling a clear forecast for sea ice. I suppose the wind direction could cause the ice extent to expand by mere distribution, but otherwise, I think we're near the escape velocity.


jdallen

  • Young ice
  • Posts: 3127
    • View Profile
  • Liked: 305
  • Likes Given: 189
Re: 2014 sea ice area and extent data
« Reply #170 on: March 11, 2014, 09:43:30 PM »
Concur with Deep Octopus.  I doubt the blast will push us past the previous max, and would be very surprised if we passed it by a significant margin.  Too far south, too much sun.
This space for Rent.

ChrisReynolds

  • Nilas ice
  • Posts: 1714
    • View Profile
    • Dosbat
  • Liked: 2
  • Likes Given: 0
Re: 2014 sea ice area and extent data
« Reply #171 on: March 11, 2014, 10:05:21 PM »
CT Area peaked 23/2, latest data is 9/3/14 and is 0.125 down on that peak. Virtually all of the maxima have happened before 20 March, little more than a week away. NSIDC Extent peaked only 6/3, but has fallen 0.23 since then.


BFTV,

I know, I've been watching that, but it doesn't seem likely to me to cause enough growth at this late stage. As you're aware some of the regions of temperature anomaly people have been marking are anomalies from an average of something like -30degC - so +10degC warm anomaly still means -20degC.

Extent is a bit more volatile IMO, being fooled by winds spreading ice out. But CT Area isn't as subject to that effect, and that's been level for two weeks.

I recognise your caution with regards previous years, but what counts is the weather conditions this year. I don't see much room for further gain in CT Area and suspect that NSIDC won't increase now.

That said, rather than post I've been playing Stalker.  8)

deep octopus

  • Grease ice
  • Posts: 559
    • View Profile
  • Liked: 8
  • Likes Given: 17
Re: 2014 sea ice area and extent data
« Reply #172 on: March 11, 2014, 10:31:09 PM »
Some data on previous dates of sea ice maxima in the recent past, from NSIDC:

March 3rd, 2000
March 4th, 2001
March 9th, 2002
March 21st, 2003
March 10th, 2004
March 12th, 2005
March 11th, 2006
March 10th, 2007
February 27th, 2008
March 2nd, 2009
March 31st, 2010
March 7th, 2011
March 4th, 2012
March 14th, 2013

Median date of maximum from 2000 to 2013 is March 9th/March 10th.

Neven

  • Administrator
  • First-year ice
  • Posts: 7616
    • View Profile
    • Arctic Sea Ice Blog
  • Liked: 982
  • Likes Given: 501
Re: 2014 sea ice area and extent data
« Reply #173 on: March 11, 2014, 11:28:28 PM »

I'm seriously pondering calling it and blogging a 'maximum' post. The problem is I suspect that whatever forecasts say, the moment I click 'post' howling -20degC winds will simultaneously burst out of Siberia and into Barents, Okhotsk & Bering.  :o

That's what happened to me in 2011 (or was it 2012?). Calling the max, max went higher, calling the max again, max went higher again. It was so embarrassing I had to laugh.  ;D
Il faut comparer, comparer, comparer, et cultiver notre jardin

pearscot

  • Frazil ice
  • Posts: 248
    • View Profile
  • Liked: 111
  • Likes Given: 43
Re: 2014 sea ice area and extent data
« Reply #174 on: March 12, 2014, 05:05:37 AM »
I enjoyed all of your comments; all quite insightful.  Given this winter and perhaps some current trends it seems like the possibility of massive changes are possible.  What I mean by that is given the 'stuck' weather patterns that seem to develop as a result a smaller differential between arctic and equatorial temperatures means that whatever patterns that develop tend to stay there for a longer period of time.  In addition, we are looking at the possibility of an El Nino developing which will have have further negative implications on the Sea Ice. How much, we can never guess but historical trends point toward it having a greater melt. 

So throw in our dismal re-freeze this winter with an average summer and the ice won't be in great shape.  End 2014 with an El Nino forming in 2015 and I can understand how the ice cap will in the hurtlocker by 2020.  Don't get wrong, I'm certainly not trying to read into this too much but I find the complexity therein interesting to say the least.  Nonetheless, this year is quite insane compared to the 'recovery' we saw last year.
pls!

Pmt111500

  • Nilas ice
  • Posts: 2119
  • Yes, I do not always bicycle
    • View Profile
  • Liked: 174
  • Likes Given: 96
Re: 2014 sea ice area and extent data
« Reply #175 on: March 12, 2014, 07:28:25 AM »
crandles asked:
Quote
Is anyone calculating what proportion of years fail to gain 125k from this date?

That sort of calculation would have to be done repeatedly each day, so I've not invested in that. Taking separate peaks (not only the maximums) in account is the time consuming step. Daily gains/losses also vary so much the result wouldn't still  be very reliable. I though started to figure out how this could be done. Using a long-period weighted average it appears there are only four occurrences, 1984, 1985, 2001 and 2003, but as the long time average hides the sharper peaks, there are others, so I can't say for certain. In order to answer, I should do the cumulative sums table using the actual values and then update daily, as I don't (yet) know how to do it automatically I'm not going to (see below). My guesstimate is 1 in 4 that 2014 hasn't yet peaked and 3 in 4 that it has. Could calculate it better but this is close to gambling anyway. New value for CT SIA is 12.8873091 Mkm2 for (astronomical?) day 2014.1863  with an anomaly of -1.2448727 Mkm2, and now I should calculate the frequency again.
« Last Edit: March 12, 2014, 02:12:15 PM by Pmt111500 »
Cooling the outside by heat pump.

Pmt111500

  • Nilas ice
  • Posts: 2119
  • Yes, I do not always bicycle
    • View Profile
  • Liked: 174
  • Likes Given: 96
Re: 2014 sea ice area and extent data
« Reply #176 on: March 12, 2014, 09:36:18 AM »
Here's the cumulative sums for 1980-2013 starting day 70.  now as 2014 is 194,4Kkm2 under the current peak, there are only 8 previous years out of 34 that would have reached new heights this year. that's little less than the previous guesstimate. I'm tired.
« Last Edit: March 12, 2014, 11:34:46 AM by Pmt111500 »
Cooling the outside by heat pump.

Jim Pettit

  • Global Moderator
  • Nilas ice
  • Posts: 1175
    • View Profile
  • Liked: 40
  • Likes Given: 11
Re: 2014 sea ice area and extent data
« Reply #177 on: March 12, 2014, 11:40:57 AM »
IJIS Extent:

14,118,547 km2 (11 March, 2014)
(2014 maximum to-date: 14,255,140 km2 06 Mar)

Up 92,823 km2 from previous day. (NOTE: largest one-day increase since 20 Feb)
Down 60,384 km2 over past seven days (daily average: -8,626 km2)
Up 93,175 km2 for the month of March (daily average: 8,470 km2)

533,219 km2 below 2000s average for this date.
233,698 km2 below 2010s average for this date.
455,707 km2 below 2012 value for this date.

Second lowest ever for the date (behind 2011).
Fourth consecutive day, and the 38th this year, among the lowest three years on record.

Third lowest March-to-date average on record (behind 2011 and 2006).


CT area:

12,887,309 km2 (10 March, 2014)
(2014 maximum to-date: 13,081,711 km2 on 23 Feb)

Down 69,347 km2 from previous day
Down 27,294 km2 over past seven days (daily average: -3,899 km2)
Down 157,118 km2 for the month of March (daily average: -15,712 km2)

841,586 km2 below 2000s average for this date.
482,851 km2 below 2010s average for this date.
718,796 km2 below 2012 value for this date. (NOTE: that's an area larger than the US state of Texas.)

Lowest ever for the date.
Third consecutive day, and 11th this year, in first place
12th consecutive day, and 33rd this year, among the lowest three years on record.

Second lowest March-to-date average on record (behind 2011).
« Last Edit: March 12, 2014, 11:50:18 AM by Jim Pettit »

Jim Pettit

  • Global Moderator
  • Nilas ice
  • Posts: 1175
    • View Profile
  • Liked: 40
  • Likes Given: 11
Re: 2014 sea ice area and extent data
« Reply #178 on: March 12, 2014, 12:06:30 PM »
CT Area:
Is anyone calculating what proportion of years fail to gain 125k from this date?

I realize this may not be precisely what you have in mind, but I produce daily CT area (and JAXA extent) graphs that show where this year's ice would end up if it followed the precise daily behavior of previous years:





CT area: http://iwantsomeproof.com/extimg/sia_projections_from_current_date.png

JAXA extent:
http://iwantsomeproof.com/extimg/sie_projections_from_current_date.png

Given the March behavior of the past several years (shown in gold), I personally won't feel safe calling the max until the first week of April.

crandles

  • Young ice
  • Posts: 2678
    • View Profile
  • Liked: 149
  • Likes Given: 53
Re: 2014 sea ice area and extent data
« Reply #179 on: March 12, 2014, 01:19:46 PM »
Thank you for answers. :)

>"Given the March behavior of the past several years (shown in gold), I personally won't feel safe calling the max until the first week of April."

Think it depends on the amount below peak as well as the date. If CT falls to 12.5 quite soon that would be enough to call it. OTOH if CT is at 13.08 on 1 April then I wouldn't want to call it.

2014.1863  -1.2448727  12.8873091  14.1321821

12.887 is 195k below peak, and
215k below previous lowest for day (2011 13.1025782)


crandles

  • Young ice
  • Posts: 2678
    • View Profile
  • Liked: 149
  • Likes Given: 53
Re: 2014 sea ice area and extent data
« Reply #180 on: March 12, 2014, 02:11:47 PM »


4 gold above average at mid April, but that could be chance with other years not showing any pattern. Does that make the pattern of movement near random or could there be a different pattern?

For example if colour coded by whether previous minimum was above or below trend, could that show any pattern? I am thinking that if the minimum is above trend that may slow down release of ocean heat in autumn and winter so that there may be some left leading to an earlier minimum.

Wipneus

  • Citizen scientist
  • Young ice
  • Posts: 4070
    • View Profile
    • Arctische Pinguin
  • Liked: 795
  • Likes Given: 0
Re: 2014 sea ice area and extent data
« Reply #181 on: March 12, 2014, 06:45:22 PM »
Calculating from NSIDC concentration data, CT Area will report approximately the following changes:

 +116.6 (today's update)
  +45.8
 +115.7

(in 1000 km2 as usual)



Jim Pettit

  • Global Moderator
  • Nilas ice
  • Posts: 1175
    • View Profile
  • Liked: 40
  • Likes Given: 11
Re: 2014 sea ice area and extent data
« Reply #182 on: March 12, 2014, 07:37:44 PM »
Calculating from NSIDC concentration data, CT Area will report approximately the following changes:

 +116.6 (today's update)
  +45.8
 +115.7

(in 1000 km2 as usual)

If so, that'll mean a new maximum in a day or two, climbing to about 13.155 million km2 to go above the to-date maximum of 13.082 million set on 0.1453. That would also be the single largest three-day March CT area increase since 2003.
« Last Edit: March 12, 2014, 09:52:29 PM by Jim Pettit »

MikeAinOz

  • New ice
  • Posts: 20
    • View Profile
  • Liked: 0
  • Likes Given: 2
Re: 2014 sea ice area and extent data
« Reply #183 on: March 13, 2014, 10:45:42 AM »
Jim, it's obviously not all over yet, you've got me downloading data too! You were so right in your doubts about the maximum, but what actually happens will be it's own story.
Mike Allen

Jim Pettit

  • Global Moderator
  • Nilas ice
  • Posts: 1175
    • View Profile
  • Liked: 40
  • Likes Given: 11
Re: 2014 sea ice area and extent data
« Reply #184 on: March 13, 2014, 12:08:50 PM »
IJIS Extent:

14,233,829 km2 (12 March, 2014)
(2014 maximum to-date: 14,255,140 km2 06 Mar)

Up 115,282 km2 from previous day. (NOTE: largest one-day increase since 30 Nov)
Up 11,125 km2 over past seven days (daily average: 1,529 km2)
Up 208,457 km2 for the month of March (daily average: 17,371 km2)

400,323 km2 below 2000s average for this date.
129,595 km2 below 2010s average for this date.
337,527 km2 below 2012 value for this date.

Fourth lowest for the date (behind 2011, 2006, and 2007).

Fourth lowest March-to-date average on record (behind 2011, 2006, and 2007).

Jim Pettit

  • Global Moderator
  • Nilas ice
  • Posts: 1175
    • View Profile
  • Liked: 40
  • Likes Given: 11
Re: 2014 sea ice area and extent data
« Reply #185 on: March 14, 2014, 11:21:55 AM »
IJIS Extent:

14,300,508 km2 (13 March, 2014)
(2014 maximum to-date)

Up 45,368 km2 from previous day. (NOTE: largest three-day increase since 30 Nov)
Up 45,368 km2 over past seven days (daily average: 6,481 km2)
Up 275,136 km2 for the month of March (daily average: 21,164 km2)

317,140 km2 below 2000s average for this date.
82,271 km2 below 2010s average for this date.
277,388 km2 below 2012 value for this date.

Fourth lowest for the date (behind 2011, 2006, and 2007).

Fourth lowest March-to-date average on record (behind 2011, 2006, and 2007).

Apocalypse4Real

  • Frazil ice
  • Posts: 370
    • View Profile
  • Liked: 5
  • Likes Given: 1
Re: 2014 sea ice area and extent data
« Reply #186 on: March 14, 2014, 04:13:08 PM »
Given surface winds and temps, I do not think we are at max area or extent yet. The following are the surface winds for March 14 2014 1200 UTC and the surface wind and temperature forecast for March 16, 2014 1200 UTC.

The current winds support sea ice transport through the Bering, Fram and other straits.

By March 16 the Bering and Fram outflows are slowed due to wind change, although the areas between Svalbard and Russia experience stronger surface winds.

Jim Hunt

  • Young ice
  • Posts: 4519
  • Stay Home, Save Lives
    • View Profile
    • The Arctic sea ice Great White Con
  • Liked: 431
  • Likes Given: 30
Re: 2014 sea ice area and extent data
« Reply #187 on: March 14, 2014, 04:22:05 PM »
Given surface winds and temps, I do not think we are at max area or extent yet.

It seems my blushes will grow ever pinker!  :-[

For context see "The 2014 Melting Season", where I "foolishly" called the 2014 maximum. In my defence I should point out that Neven offered moral support!
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

BornFromTheVoid

  • Nilas ice
  • Posts: 1002
    • View Profile
  • Liked: 32
  • Likes Given: 44
Re: 2014 sea ice area and extent data
« Reply #188 on: March 14, 2014, 05:40:06 PM »
New NSIDC max extent of 14, 860,470km2, beating the previous max set on the 6th by just over 100k.


Wipneus

  • Citizen scientist
  • Young ice
  • Posts: 4070
    • View Profile
    • Arctische Pinguin
  • Liked: 795
  • Likes Given: 0
Re: 2014 sea ice area and extent data
« Reply #189 on: March 14, 2014, 06:34:05 PM »
My estimate of CT-area's backlog is now:

+116.6   +45.8  +115.7  +113.6  +172.9

(from NSIDC gridded, calculated the CT way, delta's in 1000 km2)

Jim Pettit

  • Global Moderator
  • Nilas ice
  • Posts: 1175
    • View Profile
  • Liked: 40
  • Likes Given: 11
Re: 2014 sea ice area and extent data
« Reply #190 on: March 14, 2014, 07:39:29 PM »
My estimate of CT-area's backlog is now:

+116.6   +45.8  +115.7  +113.6  +172.9

(from NSIDC gridded, calculated the CT way, delta's in 1000 km2)

So a five-day increase of well over half-a-million square kilometers? In March? Hmm. That would mean no lower than the fourth place maximum on record (behind 2011, 2007, and 2006--and possibly 2005, as well). It would also represent--by a huge margin--the largest five-day increase ever seen in March. It would place 2014 roughly equal with, but slight ahead of, 2012. And it would mean that, over just five days, 2014 dropped all the way from first place to eighth.

Interesting...

ChrisReynolds

  • Nilas ice
  • Posts: 1714
    • View Profile
    • Dosbat
  • Liked: 2
  • Likes Given: 0
Re: 2014 sea ice area and extent data
« Reply #191 on: March 14, 2014, 08:02:51 PM »
My estimate of CT-area's backlog is now:

+116.6   +45.8  +115.7  +113.6  +172.9

(from NSIDC gridded, calculated the CT way, delta's in 1000 km2)

Thanks Wipneus.

I rarely follow sea ice day to day, but it seems that whenever I'm minded to do so CT Area data is delayed in being released. I assume that's common.

ChasingIce

  • New ice
  • Posts: 85
    • View Profile
  • Liked: 0
  • Likes Given: 0
Re: 2014 sea ice area and extent data
« Reply #192 on: March 14, 2014, 08:09:26 PM »
My estimate of CT-area's backlog is now:

+116.6   +45.8  +115.7  +113.6  +172.9

(from NSIDC gridded, calculated the CT way, delta's in 1000 km2)

Wipneus:  can you explain the "CT way" or link me to a previous explanation?

Wipneus

  • Citizen scientist
  • Young ice
  • Posts: 4070
    • View Profile
    • Arctische Pinguin
  • Liked: 795
  • Likes Given: 0
Re: 2014 sea ice area and extent data
« Reply #193 on: March 15, 2014, 08:52:42 AM »
My estimate of CT-area's backlog is now:

+116.6   +45.8  +115.7  +113.6  +172.9

(from NSIDC gridded, calculated the CT way, delta's in 1000 km2)

Wipneus:  can you explain the "CT way" or link me to a previous explanation?

Always happy to explain.

1) CT is delayed 2 days in respect to the NSIDC data (both gridded data and extent).
2) The NSIDC sea ice concentration data is specified on a polar stereographic  grid. This grid is non equal area, at 70o latitude the grid cell measures 25x25 km=625 km2. At the pole the true size is about 6% bigger, at the latitude of St.Lawrence it is a lot smaller: 66% of the nominal size.
CT ignores the true size and thus amplifies the St.Lawrence by a factor 3/2.
3) CT includes all ice, also sea ice outside the 14 regions but also includes lake ice. This is an interesting point, NSIDC extent is calculated for all ice, but not the lakes.

The result is near enough but not perfect, some regions differ for unexplained reasons and perhaps the way the "pole hole" is filled is not the same. Without the points above, the results differ substantially.

Attached the daily differences of CT area and my calculation compared. Not perfect, but near enough.

Please ask if any questions remain.

Jim Pettit

  • Global Moderator
  • Nilas ice
  • Posts: 1175
    • View Profile
  • Liked: 40
  • Likes Given: 11
Re: 2014 sea ice area and extent data
« Reply #194 on: March 15, 2014, 01:22:39 PM »
IJIS Extent:

14,305,537 km2 (14 March, 2014)
(2014 maximum to-date)
Five years from 2004-2013 had seen their maximum on or before this date. Five others, including four of the past five, had not.

Up 5,029 km2 from previous day.
Up 101,409 km2 over past seven days (daily average: 14,487 km2)
Up 280,165 km2 for the month of March (daily average: 20,012 km2)

294,550 km2 below 2000s average for this date.
94,215 km2 below 2010s average for this date.
266,244 km2 below 2012 value for this date.

Fifth lowest for the date (behind 2006, 2011, 2007, and 2005).

Fourth lowest March-to-date average on record (behind 2011, 2006, and 2007).


CT area:

13,278,053 km2 (14 March, 2014)
2014 maximum to-date
NOTE: The four-day increase of 390,744 km2 is by a significant margin the largest ever recorded in the month of March. In fact, only one similar increase has ever even been measured in the month of February, and that was in the first week of the month in 1997.)
(NOTE: data for 0.1891 (11 Mar) is missing)

Up 118,711 km2 from previous day
Up 220,372 km2 over past seven days (daily average: 31,482 km2)
Up 233,626 km2 for the month of March (daily average: 16,688 km2)

363,276 km2 below 2000s average for this date.
147,177 km2 below 2010s average for this date.
242,011 km2 below 2012 value for this date.

Fourth lowest for the date (behind 2011, 2007, and 2006)

Second lowest March-to-date average on record (behind 2011).
« Last Edit: March 15, 2014, 03:13:56 PM by Jim Pettit »

Buddy

  • Young ice
  • Posts: 3379
  • Go DUCKS!!
    • View Profile
  • Liked: 52
  • Likes Given: 34
Re: 2014 sea ice area and extent data
« Reply #195 on: March 15, 2014, 01:38:36 PM »
One thing of interest to watch this year, will be the temperature anomaly in the Arctic from day 125 through day 240 (early April through late August........in other words, MOST of the melt season).

If you look at the 2nd and 3rd charts on the page from the link below, you will see that last year (2013) the Arctic had a COOL ANOMALY starting from day 125 all the way through day 240 (early April to late August).

http://climatechangegraphs.blogspot.com/2012/08/arctic-sea-ice-volume-extent-charts_30.html

It will be interesting to see if that holds for this year.  I would NOT expect the same this year.

FOX (RT) News....."The Trump Channel.....where truth and journalism are dead."

Wipneus

  • Citizen scientist
  • Young ice
  • Posts: 4070
    • View Profile
    • Arctische Pinguin
  • Liked: 795
  • Likes Given: 0
Re: 2014 sea ice area and extent data
« Reply #196 on: March 15, 2014, 02:26:01 PM »
My estimate of CT-area's backlog is now:

+116.6   +45.8  +115.7  +113.6  +172.9

(from NSIDC gridded, calculated the CT way, delta's in 1000 km2)

After the second update today, CT area reported:

+120.4   +44.9  +106.8  +118.7

(last value is expected tomorrow, due to the 2 day CT delay)

ChrisReynolds

  • Nilas ice
  • Posts: 1714
    • View Profile
    • Dosbat
  • Liked: 2
  • Likes Given: 0
Re: 2014 sea ice area and extent data
« Reply #197 on: March 15, 2014, 02:32:04 PM »
2) The NSIDC sea ice concentration data is specified on a polar stereographic  grid. This grid is non equal area, at 70o latitude the grid cell measures 25x25 km=625 km2. At the pole the true size is about 6% bigger, at the latitude of St.Lawrence it is a lot smaller: 66% of the nominal size.
CT ignores the true size and thus amplifies the St.Lawrence by a factor 3/2.

I didn't realise that, don't get the time to read everything here. It's not good. I'll have to reconsider whether I continue to use CT Area.

Jim Hunt

  • Young ice
  • Posts: 4519
  • Stay Home, Save Lives
    • View Profile
    • The Arctic sea ice Great White Con
  • Liked: 431
  • Likes Given: 30
Re: 2014 sea ice area and extent data
« Reply #198 on: March 15, 2014, 02:57:00 PM »
Chris/Wipneus - Do either of you by any chance know the intimate details of the domain covered for the DMI/NORSEX extent numbers. In particular do they suffer the same sort of issue as the one you describe for CT?

I've looked at this lot, but I'm afraid I'm currently none the wiser! http://www.osi-saf.org/biblio/bibliotheque.php
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

Jim Pettit

  • Global Moderator
  • Nilas ice
  • Posts: 1175
    • View Profile
  • Liked: 40
  • Likes Given: 11
Re: 2014 sea ice area and extent data
« Reply #199 on: March 15, 2014, 03:16:27 PM »
2) The NSIDC sea ice concentration data is specified on a polar stereographic  grid. This grid is non equal area, at 70o latitude the grid cell measures 25x25 km=625 km2. At the pole the true size is about 6% bigger, at the latitude of St.Lawrence it is a lot smaller: 66% of the nominal size.
CT ignores the true size and thus amplifies the St.Lawrence by a factor 3/2.

I didn't realise that, don't get the time to read everything here. It's not good. I'll have to reconsider whether I continue to use CT Area.

For that, and other reasons, I plan to retire my CT area logging and visualizations and switch to a different metric, perhaps within a month or so.