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Neven

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NSIDC
« on: October 27, 2013, 09:54:53 PM »
Up till now we discussed everything pertaining to NSIDC sea ice extent in threads for monthly polls. Now that the melting season is over, I suggest we continue in this central thread (like the IJIS/JAXA thread that is regularly updated by Espen).

Have at it...
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Wipneus

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Re: NSIDC
« Reply #1 on: October 28, 2013, 07:44:09 AM »
Last valid daily update was October 22.

NSIDC sea ice news page shows:

Quote
October 25, 2013: Daily updates to the graph and image are temporarily suspended due to technical difficulties with the data provider.

The data seems to be the SSM/IS instrument DMSP satellite F17.

Other data users (Arctic Roos, Uni Hamburg) have stopped as well.

The Bremens SSMIS page still mentions F17, but according to the captions, the graphs are now using the successor F18.

Jim Hunt

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Re: NSIDC
« Reply #2 on: October 28, 2013, 08:09:32 PM »
The last Bremen F17 image is indeed from the 22nd:

http://www.iup.uni-bremen.de:8084/ssmis/archivebrowse.php?date=20131022&region=Arctic&hemisphere=n&sensor=SSMIS17&ctab=visual#map

First a Government shutdown. Now a satellite shutdown? I hope these things don't come in threes :(
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

ChrisReynolds

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Re: NSIDC
« Reply #3 on: October 29, 2013, 08:56:20 PM »
They already have Jim,

The flooding at Boulder preceded those two events.

ggelsrinc

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Re: NSIDC
« Reply #4 on: October 29, 2013, 10:28:14 PM »
The last Bremen F17 image is indeed from the 22nd:

http://www.iup.uni-bremen.de:8084/ssmis/archivebrowse.php?date=20131022&region=Arctic&hemisphere=n&sensor=SSMIS17&ctab=visual#map

First a Government shutdown. Now a satellite shutdown? I hope these things don't come in threes :(

NSIDC is simply a small government grant to a college that re-analyses DOD Navy information from a satellite, designed for defense purposes and I don't think it's a satellite shutdown. My opinion evolves from once researching the history of NSIDC, when a Denialista asked why it was necessary if we had NOAA. I researched both and pointed out it was for defense and commerce purposes, amongst other obvious ramifications of why a government would be interested in climate research.

I think the current problems are a product of only intermittent chump change being given to a college and the simple fact that much of that work is a volunteer effort. I believe it's a backlog of effort resulting from the shutdown and I don't blame the workers. There are only so many hours in a day and I won't want to do the required work, even when paid.

My analysis of the present problem is based on my limited experience of examining the subject and I don't claim it's conclusive. I seriously doubt our DOD isn't getting the satellite information it once did and uses.   

Jim Hunt

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Re: NSIDC
« Reply #5 on: October 30, 2013, 06:33:03 PM »
Google led me to this: http://www.remss.com/missions/ssmi

Quote
We obtain SSMIS instrument data from NOAA CLASS.  They have been down several times in the past week for computer problems.  When they get started again, they continue to provide data, but do not send us back data that was missed during the outage.  We have ordered back data, but are waiting for it to arrive.  As of Oct 30th 10 am PST, we are missing data for both F16 and F17 SSMIS during two time periods:  Oct 23rd - 25th and Oct 27th - 29th.
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Wipneus

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Re: NSIDC
« Reply #6 on: November 01, 2013, 08:57:21 AM »
Uni Hamburg has resumed producing ssmis concentration data labeled "F17"

Jim

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Re: NSIDC
« Reply #7 on: November 05, 2013, 10:37:47 AM »
It's Baaaack!!  :)
....well, sort of. The front page still shows old data and the 'not updating' message, but clicking on the chart (and on the Charctic Interactive graph) will show up to date info.

Wipneus

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Re: NSIDC
« Reply #8 on: November 06, 2013, 05:55:16 PM »
Broken again  :-\


Jim Hunt

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Re: NSIDC
« Reply #9 on: November 07, 2013, 01:10:47 AM »
There's a new Arctic Sea Ice News:

"A typical October in the Arctic"

Quote
Average ice extent for October was 8.10 million square kilometers (3.13 million square miles), making it the 6th lowest October extent in the 35-year satellite data record.
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

BornFromTheVoid

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Re: NSIDC
« Reply #10 on: November 09, 2013, 05:13:08 PM »
The latest view of things



I recently joined the twitter thing, where I post more analysis, pics and animations: @Icy_Samuel

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Re: NSIDC
« Reply #11 on: November 09, 2013, 06:01:05 PM »
My eyes aren't the keenest, nor is my interest in number crunching that strong to convince Denialistas of simple facts, because I know there is no use in wasting the effort, but I don't see a past comparison in that NSIDC data chart to the recent events. Has anyone checked the recent record with all NSIDC satellite data to see how this statistically compares to this season of the year or other seasons to prove statistical significance? I guess that is cherry picking in a way, like they do in a way, but I don't see that happening before based on the data of that chart. It's what I see and may be just my eyesight.

It reminds and looks to me like there will be no joy in Mudville, but I'm not mighty Casey or the umpire, just a fan in the cheap seats.

Wipneus

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Re: NSIDC
« Reply #12 on: November 11, 2013, 04:54:43 PM »
NSIDC reports a drop of -2.1M today:

2013,    11,  06,    9.33091,    0.00000,
2013,    11,  07,    9.32406,    0.00000,
2013,    11,  08,    9.21649,    0.00000,
2013,    11,  09,    9.27397,    0.00049,
2013,    11,  10,    7.15330,    5.13051,

The reason is in column 4: 5.1 million km2 is missing. Actually all is missing and also November 9 is missing a bit more than the tiny 0.49k.



Sourabh

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Re: NSIDC
« Reply #13 on: November 11, 2013, 05:27:45 PM »
NSIDC reports a drop of -2.1M today:

The reason is in column 4: 5.1 million km2 is missing. Actually all is missing and also November 9 is missing a bit more than the tiny 0.49k.


What do you mean by missing? What is missing? I see daily images are missing, but they still updated the 'interactive graph'. Also, I checked on NSIDC website, 9th Nov, ice extent is about 9.29 m km2, and 10th Nov it is 8.86m km2, which is drop of 0.43m km2. Now, is it me who is "missing" ( ;D) something?
« Last Edit: November 11, 2013, 05:34:57 PM by sourabhtheone »

Wipneus

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Re: NSIDC
« Reply #14 on: November 11, 2013, 06:48:46 PM »
sourabh,

The data is Arctic sea ice concentration on a 25x25km grid in here:
ftp://sidads.colorado.edu/pub/DATASETS/nsidc0081_nrt_nasateam_seaice/north/nt_20131109_f17_nrt_n.bin
and
ftp://sidads.colorado.edu/pub/DATASETS/nsidc0081_nrt_nasateam_seaice/north/nt_20131110_f17_nrt_n.bin

These data are used as input to a number of calculations, including as we think the area numbers reported by Cryosphere Today (with some delay).
Binary files, not easy to inspect, so I showed the images now on the NSIDC server. The  nt_20131110_f17_nrt_n.bin file is filled with "Data Not Available" values. But you are welcome to verify that yourself.

NSIDC computes every day the total extent from these bin files, you can download that here:

ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/north/daily/data/NH_seaice_extent_nrt.csv

It is a text file, easy to open, and you will find I posted the last lines in my post.

I don't know where you found the 9.29 and 8.86 figures.
« Last Edit: November 12, 2013, 07:38:08 AM by Wipneus »

Sourabh

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Re: NSIDC
« Reply #15 on: November 11, 2013, 07:24:13 PM »
sourab,

I don't know where you found the 9.29 and 8.86 figures.

 Wipneus,

Thanks for your reply. I wasn't questioning your integrity or honesty. I generally follow what is on NSIDC.org. So, those numbers were different than what you posted.

I read that data from NSIDC website.

http://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/

I am not sure if these numbers are delayed, inaccurate, or processed differently.

ggelsrinc

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Re: NSIDC
« Reply #16 on: November 11, 2013, 08:42:30 PM »
I haven't spent time in the past analyzing refreeze of ASI and only did so last year and this one, because I thought it was boring. My focus on ASI was so caught in the present that I didn't look for trends over time.

Now that I've spent a little time analyzing the NSIDC data, I've noticed certain patterns. The obvious patterns of maximum and minimum aren't remarkable. The patterns I find odd are in the refreeze periods. I'll examine the data in more detail later, but for now, I'll ask this simple question. Does anyone else see refreeze reversals like I see?

jdallen

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Re: NSIDC
« Reply #17 on: November 11, 2013, 09:18:56 PM »
@ggelsrinc - just examinining Wipneus' graphs above show previous periods of "leveling off" and minor reversals in refreeze. I think it may be notable that one of those appears to be in 2008. What sets this year apart looks to be magnitude.

Neven noted elsewhere that the Arctic Oscillation is gone positive - strongly so, higher and more persistently than any time in the last year.  Wind may be a factor, compressing the pack, as suggested by a powerful low squatting in the GIUK gap.

Add to that, I suspect that airflow may be bringing a lot of heat, which would interfere with seawater dumping it into the atmosphere.  Time to look at the weather maps to figure out what's being shoved around by the storms.
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jdallen

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Re: NSIDC
« Reply #18 on: November 11, 2013, 09:27:13 PM »
Speaking of weather in parallel, I wonder if this might be a side effect of instability of the Hadley cells?
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ggelsrinc

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Re: NSIDC
« Reply #19 on: November 11, 2013, 09:51:35 PM »
@ggelsrinc - just examinining Wipneus' graphs above show previous periods of "leveling off" and minor reversals in refreeze. I think it may be notable that one of those appears to be in 2008. What sets this year apart looks to be magnitude.

Neven noted elsewhere that the Arctic Oscillation is gone positive - strongly so, higher and more persistently than any time in the last year.  Wind may be a factor, compressing the pack, as suggested by a powerful low squatting in the GIUK gap.

Add to that, I suspect that airflow may be bringing a lot of heat, which would interfere with seawater dumping it into the atmosphere.  Time to look at the weather maps to figure out what's being shoved around by the storms.

That's what I saw too, because 2007 sticks in my brain. I need to check the data better to make my case, but I see serious problems with refreeze and not serious problems with melt. There could be something statistically significant there, or just an old man's eyes. I allow facts to determine themselves. My science grows young and I am only starting to open my eyes.

jdallen

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Re: NSIDC
« Reply #20 on: November 11, 2013, 10:05:44 PM »
Quite so, ggelsrinc.  More grist - have a look at the SST anomalies.  That heat is coming from seawater.  Temperatures posted by the DMI are pretty warm as well.  If the oceanic heat can't get into the atmosphere, it would go straight into the ice.  If the ice is relatively thin at the margins as we would expect at this point, mostly < 50cm, that heat would both melt and weaken it.

http://www.esrl.noaa.gov/psd/map/clim/sst.shtml
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jdallen

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Re: NSIDC
« Reply #21 on: November 11, 2013, 10:13:57 PM »
... but I see serious problems with refreeze and not serious problems with melt...

It strikes me... Maybe our obsession with melt has caused us to miss something strategic here?!
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ggelsrinc

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Re: NSIDC
« Reply #22 on: November 11, 2013, 10:53:22 PM »
Quite so, ggelsrinc.  More grist - have a look at the SST anomalies.  That heat is coming from seawater.  Temperatures posted by the DMI are pretty warm as well.  If the oceanic heat can't get into the atmosphere, it would go straight into the ice.  If the ice is relatively thin at the margins as we would expect at this point, mostly < 50cm, that heat would both melt and weaken it.

http://www.esrl.noaa.gov/psd/map/clim/sst.shtml

I think it's because the data sucks, but I can understand your interpretation particularly around areas near the Atlantic.

My point is if there are statistically proven changes in the refreeze, it's possible my hypothesis about a negative feedback based on the strength of ASI may be true and that's just a minor point. The main point is what it says about global warming and my hope it will buy us some time. I only started thinking that way (looking for negative feedbacks) by a question asked on ASIB. My prognosis has been ASI is terminal, but I'm not an ice doctor. If I were, I'd be up there making ASI and no government in this world could stand up to my Indigenous desire to do so.

I think there is something obvious in the refreeze data that I haven't heard others talk about. Consider Dylan Thomas:

Quote
Do not go gentle into that good night,
Old age should burn and rage at close of day;
Rage, rage against the dying of the light.
Though wise men at their end know dark is right,
Because their words had forked no lightning they
Do not go gentle into that good night.

Good men, the last wave by, crying how bright
Their frail deeds might have danced in a green bay,
Rage, rage against the dying of the light.

Wild men who caught and sang the sun in flight,
And learn, too late, they grieved it on its way,
Do not go gentle into that good night.

Grave men, near death, who see with blinding sight
Blind eyes could blaze like meteors and be gay,
Rage, rage against the dying of the light.

And you, my father, there on the sad height,
Curse, bless me now with your fierce tears, I pray.
Do not go gentle into that good night.
Rage, rage against the dying of the light.

Source: http://www.bigeye.com/donotgo.htm

It's not over, until it's over!

Wipneus

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Re: NSIDC
« Reply #23 on: November 12, 2013, 07:58:25 AM »
Thanks for your reply. I wasn't questioning your integrity or honesty. I generally follow what is on NSIDC.org. So, those numbers were different than what you posted.

I read that data from NSIDC website.

http://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/

I am not sure if these numbers are delayed, inaccurate, or processed differently.

What I know is that the extent graph is composed of a 5 day trailing (last 5 days) average.
From the detailed description of the Sea Ice Index, section Daily Image and Data Files find:

Quote
Reduce erroneous artifacts.
On daily scales, these extent values can have fairly large variations, both due to real changes in ice extent from growth, melt, or from motion of the ice edge, and due to ephemeral weather and surface effects. To reduce erroneous variations, a 5-day trailing mean is used in the plot. This is calculated by averaging the extent value from a given day with the extent value from the previous four days to produce a 5-day average, so the value plotted for a day is the average of that day and the four previous days.

I don't know, but it is likely that this is true for the interactive graph as well.

The averaging of course makes daily scale features like the "Hiatus" less prominent. So some prefer the unfiltered daily values.

BornFromTheVoid

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Re: NSIDC
« Reply #24 on: November 13, 2013, 12:47:38 PM »
Hopefully the NISDC data is back consistently now

Update for the week to November 9th

The current 1 day extent is 9,324,460km2, while the 5 day mean is on 9,304,128km2

The daily anomaly (compared to 79-11) is at -915,140km2, an increase from -594,170km2 last week. The anomaly compared to the 07, 11 and 12 average has decreased from +683,280km2 to +200,693km2 this week. We're currently 5th lowest on record, compared to 7th lowest last week.

The average daily increase over the last 7 days was +13.4k/day, compared to the long term average of +59.3k/day, and the average of the last 5 years of +79.2k/day.

The average long term increase over the next week is +69.3k/day, with the average of the last 5 years being +78.5k/day.

The increase so far this November is the 2nd smallest on record. To record the largest November gain in total, an average daily increase of 118k/day is required for the next 21 days.



I recently joined the twitter thing, where I post more analysis, pics and animations: @Icy_Samuel

Wipneus

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Re: NSIDC
« Reply #25 on: November 20, 2013, 08:47:58 AM »
NSIDC reported +144k for Hudson Bay extent alone. Reason for a closer look. Attached a comparison with the AMSR2 sea ice concentration from Jaxa. NSIDC sees a lot of ice in the south of Hudson, where Jaxa sees very little.


werther

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Re: NSIDC
« Reply #26 on: November 20, 2013, 10:26:33 AM »
Morning Wipneus,

Having checked some Arctic weather I read your post. Seems to me NSIDC is spotting something different over there. Reports show the area experiencing 1-2 dC plus anomaly daily max and up to +4dC daily min for November up to now. Given a 'climatologic' mean freeze up beginning of December, it seems almost impossible for it to happen now with these anomalies.

Another weather feature of some interest is what's going on N of Svalbard/Frantsa Yosefa, but that's another thread, I think...

TerryM

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Re: NSIDC
« Reply #27 on: November 20, 2013, 02:27:18 PM »
Environment Canada is showing less than 1/10th concentration in Southern James Bay. The water there is very fresh.
http://ice-glaces.ec.gc.ca/prods/WIS30CT/20131119180000_WIS30CT_0007373561.pdf
Terry

ghoti

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Re: NSIDC
« Reply #28 on: November 20, 2013, 03:56:40 PM »
And there is no way  the St Lawrence river is completely frozen from Quebec City east as the NSIDC map suggests.

Wipneus

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Re: NSIDC
« Reply #29 on: November 20, 2013, 05:20:54 PM »
And there is no way  the St Lawrence river is completely frozen from Quebec City east as the NSIDC map suggests.

Indeed, it is an problem with the instrument (ssmis) and algorithms but also the masking that NSIDC uses. During summer it is masked away, but from November 1 it is calculated (in 1000 km2):

NSIDC
nr.            date         St..Lawrence.extent St..Lawrence.area
12784       20131025             0.00000           0.00000
12785       20131026             0.00000           0.00000
12786       20131027             0.00000           0.00000
12787       20131028             0.00000           0.00000
12788       20131029             0.00000           0.00000
12789       20131030             0.00000           0.00000
12790       20131031             0.00000           0.00000
12791       20131101            39.52116          18.04964
12792       20131102            35.97622          16.55618
12793       20131103            26.77626          11.76691
12794       20131104            21.15203          10.29686
(...)
12808       20131118            44.14450          19.67242


Jaxa's numbers are more than an order in magnitude better and no sudden mask bumps:

JAXA
nr        date     St..Lawrence.extent St..Lawrence.area
480     20131026          0.95689949        0.27714079
481     20131027          2.31657386        0.57318342
482     20131028          2.16980244        0.65947690
483     20131029          1.20223540        0.33003711
484     20131030          1.20464481        0.36238748
485     20131031          1.20433973        0.36345679
486     20131101          0.16061650        0.02666234
487     20131102          1.28760265        0.36742741
488     20131103          0.08016646        0.01719571
489     20131104          1.51509304        0.47555172
(...)
503     20131118          2.02662566        0.73855530


BornFromTheVoid

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Re: NSIDC
« Reply #30 on: November 23, 2013, 12:43:13 PM »
Apologies for the delayed update...

Update for the week to November 16th

The current 1 day extent is 9,779,690km2, while the 5 day mean is on 9,672,180km2

The daily anomaly (compared to 79-11) is at -949,470km2, an increase from -915,140km2 last week. The anomaly compared to the 07, 11 and 12 average has decreased from +200,693km2 to +145,013km2 this week. We're currently 5th lowest on record, the same as last week.

The average daily increase over the last 7 days was +65.0k/day, compared to the long term average of +69.3k/day, and the average of the last 5 years of +78.5k/day.

The average long term increase over the next week is +63.6k/day, with the average of the last 5 years being +77.1k/day.

I recently joined the twitter thing, where I post more analysis, pics and animations: @Icy_Samuel

BornFromTheVoid

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Re: NSIDC
« Reply #31 on: November 24, 2013, 07:28:18 PM »
Update for the week to November 23rd

The current 1 day extent is 10,502,100km2, while the 5 day mean is on 10,328,510km2

The daily anomaly (compared to 79-11) is at -671,980km2, a decrease from -949,470km2 last week. The anomaly compared to the 07, 11 and 12 average has increased from +145,013km2 to +250,010km2 this week. We're currently 7th lowest on record, compared to 5th last week.

The average daily increase over the last 7 days was +103.2k/day, compared to the long term average of +63.6k/day, and the average of the last 5 years of +77.1k/day.

The average long term increase over the next week is +74.7k/day, with the average of the last 5 years being +70.2k/day.

The increase so far this November is the 16th smallest on record. To record the largest November gain in total, an average daily increase of 184.8k/day is required for the next 7 days. To record the smallest November gain, an daily average of -42.9k/day is required.

« Last Edit: November 25, 2013, 11:53:22 AM by BornFromTheVoid »
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BornFromTheVoid

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Re: NSIDC
« Reply #32 on: December 01, 2013, 06:38:48 PM »
Update for the week to November 30th

The current 1 day extent is 11,147,580km2, while the 5 day mean is on 10,966,370km2

The daily anomaly (compared to 79-11) is at -549,740km2, a decrease from -671,980km2 last week. The anomaly compared to the 07, 11 and 12 average has increased from +250,010km2 to +349,753km2 this week. We're currently 8th lowest on record, compared to 7th last week.

The average daily increase over the last 7 days was +92.2k/day, compared to the long term average of +74.7k/day, and the average of the last 5 years of +70.2k/day.

The average long term increase over the next week is +92.9k/day, with the average of the last 5 years being +103.2k/day.

The increase this November was the 14th largest on record.



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Re: NSIDC
« Reply #33 on: December 01, 2013, 09:17:18 PM »

The increase this November was the 14th largest on record.


In other words, solidly in the middle of the "pack", compared to the rest of the record.

Ok, I apologize for the cheap pun.  It is still both interesting and relevant to our understanding of the system.  It is notable the refreezes of 2012 and 2007 are respectively the 1st and 2nd largest on record.  I think with thinner ice, this will become an increasingly volatile metric.
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Re: NSIDC
« Reply #34 on: December 08, 2013, 05:38:52 PM »
Update for the week to December 7th

The current 1 day extent is 11,673,490km2, while the 5 day mean is on 11,698,430km2

The daily anomaly (compared to 79-11) is at -674,250km2, an increase from -549,740km2 last week. The anomaly compared to the 07, 11 and 12 average has increased from +349,753km2 to +216,477km2 this week. We're currently 7th lowest on record, compared to 8th last week.

The average daily increase over the last 7 days was +75.1k/day, compared to the long term average of +92.9k/day, and the average of the last 5 years of +103.2k/day.

The average long term increase over the next week is +63.1k/day, with the average of the last 5 years being +70.6k/day.

The gain so far this December is the 7th lowest on record. To record the largest December gain, an daily increase of 95.8k/day or higher is required. The lowest gain requires 36.0k/day or less.

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Re: NSIDC
« Reply #35 on: December 15, 2013, 08:25:45 PM »
Update for the week to December 14th

The current 1 day extent is 12,154,680km2, while the 5 day mean is on 12,071,490km2

The daily anomaly (compared to 79-11) is at -704,580km2, an increase from -674,250km2 last week. The anomaly compared to the 07, 11 and 12 is at 259,087km2 an increase from 216,477km2. We're currently 5th lowest on record, compared to 7th last week.

The average daily increase over the last 7 days was +68.7k/day, compared to the long term average of +63.1k/day, and the average of the last 5 years of +70.6k/day.

The average long term increase over the next week is +53.5k/day, with the average of the last 5 years being +51.5k/day.

The gain so far this December is the 6th lowest on record. To record the largest December gain, a daily increase of 113.6k/day or higher is required. The lowest gain requires 23.9k/day or less.

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Re: NSIDC
« Reply #36 on: December 22, 2013, 04:08:18 PM »
Update for the week to December 21st

The current 1 day extent is 12,353,910km2, while the 5 day mean is on 12,268,420km2

The daily anomaly (compared to 79-11) is at -821,590km2, an increase from -704,580km2 last week. The anomaly compared to the 07, 11 and 12 is at -69,810km2 a decrease from 259,087km2, and below them for the first time since April. We're currently 3rd lowest on record, compared to 5th last week.

The average daily increase over the last 7 days was +28.5k/day, compared to the long term average of +53.3k/day, and the average of the last 5 years of +51.5k/day.

The average long term increase over the next week is +45.0k/day, with the average of the last 5 years being +56.3k/day.

The gain so far this December is the 6th lowest on record. To record the largest December gain, a daily increase of 179.8k/day or higher is required. The lowest gain requires 20.3k/day or less.

« Last Edit: January 05, 2014, 04:20:58 PM by BornFromTheVoid »
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Re: NSIDC
« Reply #37 on: December 22, 2013, 06:37:12 PM »
Thank you, BFTV!
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Re: NSIDC
« Reply #38 on: January 05, 2014, 04:49:44 PM »
No worries Neven.

Sorry for the break last week, just a bit busy during the festive period!

Anywho, update for the week to December 28th

The current 1 day extent is 12,840,700km2, while the 5 day mean is on 12,639,830km2

The daily anomaly (compared to 79-11) is at -657,100km2, a decrease from -821,590km2 last week. The anomaly compared to the 07, 11 and 12 average is at -12,440km2, a change from -69,810km2 last week. We're currently 4th lowest on record, compared to 3rd last week.

The average daily increase over the last 7 days was +69.5k/day, compared to the long term average of +45.0k/day, and the average of the last 5 years of +56.3k/day.

The average long term increase over the next week is +60.1k/day, with the average of the last 5 years being +58.8k/day.

The gain so far this December is the 14th lowest on record. To record the largest December gain, a daily increase of 377.2k/day or higher is required. The lowest gain requires a loss of at least -101.4k/day.

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Re: NSIDC
« Reply #39 on: January 05, 2014, 05:12:26 PM »
Update for the week to January 4th

The current 1 day extent is 13,220,090km2, while the 5 day mean is on 13,039,250km2

The daily anomaly (compared to 79-11) is at -698,390km2, an increase from -657,100km2 last week. The anomaly compared to the 07, 11 and 12 average is at +22,517km2 a change from -12,440km2. We're currently 4th lowest on record, the same as last week.

The average daily increase over the last 7 days was +54.2k/day, compared to the long term average of +60.1k/day, and the average of the last 5 years of +56.3k/day.

The average long term increase over the next week is +44.2k/day, with the average of the last 5 years being +54.0k/day.



The increase for the first 4 days of January is by far the largest on record. For the largest total January gain on record, a daily average of at least 48.5k/day is required for the rest of the month, with the smallest gain requiring 14.7k/day or less.


The gain for December 2013 was the 9th lowest on record.

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Re: NSIDC
« Reply #40 on: January 06, 2014, 04:17:17 PM »
2014,    01,  04,   13.22008
2014,    01,  05,   13.12213

Large downward step - very nearly a century break!

Now 2nd lowest only to
2013,    01,  05,   12.99966

though perhaps 2nd= would be more appropriate given how close to 2011:

2011,    01,  05,   13.12279

(but then I might have to think about whether 0.123 is significant ...)

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Re: NSIDC
« Reply #41 on: January 06, 2014, 04:31:59 PM »

Large downward step - very nearly a century break!


I was wondering yesterday why nsidc showed nearly a century in growth, where other indices show slight declines. This looks like the step to put things right, see the diffmap and look at the east of New Foundland:


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Re: NSIDC
« Reply #42 on: January 06, 2014, 09:31:01 PM »
Overall, things look remarkably normal.

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Re: NSIDC
« Reply #43 on: January 06, 2014, 10:30:11 PM »
Overall, things look remarkably normal.

"Look" is the operative verb here.  We start drilling into various non-visual quantitative dimensions, "normal"starts getting twisted into a balloon animal.

 Makes me think of looking at the coat of bright fresh paint sprayed on to floorboards with dry rot, just after you have stepped on to them and fallen through to the basement.
« Last Edit: January 07, 2014, 09:02:52 AM by jdallen »
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Re: NSIDC
« Reply #44 on: January 07, 2014, 03:59:08 AM »
Overall, things look remarkably normal.

Sea ice still white and frozen?

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Re: NSIDC
« Reply #45 on: January 12, 2014, 07:46:48 PM »
The current 1 day extent is 13,417,800km2, while the 5 day mean is on 13,266,570km2

The daily anomaly (compared to 79-11) is at -810,280km2, an increase from -698,390km2 last week. The anomaly compared to the 07, 11 and 12 average is at +65,303km2 a change from -22,517km2. We're currently 3rd lowest on record, down from 4th last week.

The average daily increase over the last 7 days was +28.2k/day, compared to the long term average of +44.2k/day, and the average of the last 5 years of +54.0k/day.

The average long term increase over the next week is +38.5k/day, with the average of the last 5 years being +32.6k/day.

The increase for the first 11 days of January is the 11th largest on record. For the largest total January gain on record, a daily average of at least 55.6k/day is required for the rest of the month, with the smallest gain requiring 10.0k/day or less.

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Re: NSIDC
« Reply #46 on: January 19, 2014, 04:05:29 PM »
Update for the week to January 18th

The current 1 day extent is 13,704,090km2, while the 5 day mean is on 13,595,900km2

The daily anomaly (compared to 79-11) is at -793,260km2, a decrease from -810,280km2 last week. The anomaly compared to the 07, 11 and 12 average is at +107,730km2 a change from +65,303km2. We're currently 5th lowest on record, up from 3rd last week.

The average daily increase over the last 7 days was +34.8k/day, compared to the long term average of +38.5k/day, and the average of the last 5 years of +32.6k/day.

The average long term increase over the next week is +35.6k/day, with the average of the last 5 years being +28.4k/day.

The increase for the first 18 days of January is the 11th largest on record. For the largest total January gain on record, a daily average of at least 63.6k/day is required for the rest of the month, with the smallest gain requiring a loss of at least 6.7k/day.

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Re: NSIDC
« Reply #47 on: January 19, 2014, 04:57:12 PM »
Being a "bean counter".....I LOVE this analysis you do, and think it is VERY informative AND useful, so thank you:)
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Re: NSIDC
« Reply #48 on: January 26, 2014, 04:25:52 PM »
Cheers Buddy!

Update for the week to January 25th

The current 1 day extent is 14,056,840km2, while the 5 day mean is on 13,954,210km2

The daily anomaly (compared to 79-11) is at -689,540km2, a decrease from -793,260km2 last week. The anomaly compared to the 07, 11 and 12 average is at +142,990km2 a change from +107,730km2. We're currently 6th lowest on record, up from 5th last week.

The average daily increase over the last 7 days was +50.4k/day, compared to the long term average of +35.6k/day, and the average of the last 5 years of +28.4k/day.

The average long term increase over the next week is +35.9k/day, with the average of the last 5 years being +35.0k/day.

The increase for the first 25 days of January is the 9th largest on record. For the largest total January gain on record, a daily average of at least 79.0k/day is required for the rest of the month, with the smallest gain requiring a loss of at least 73.2k/day.

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Re: NSIDC
« Reply #49 on: January 27, 2014, 03:38:24 AM »
Cheers Buddy!

Update for the week to January 25th

The current 1 day extent is 14,056,840km2, while the 5 day mean is on 13,954,210km2

The daily anomaly (compared to 79-11) is at -689,540km2, a decrease from -793,260km2 last week. The anomaly compared to the 07, 11 and 12 average is at +142,990km2 a change from +107,730km2. We're currently 6th lowest on record, up from 5th last week.

The average daily increase over the last 7 days was +50.4k/day, compared to the long term average of +35.6k/day, and the average of the last 5 years of +28.4k/day.

The average long term increase over the next week is +35.9k/day, with the average of the last 5 years being +35.0k/day.

The increase for the first 25 days of January is the 9th largest on record. For the largest total January gain on record, a daily average of at least 79.0k/day is required for the rest of the month, with the smallest gain requiring a loss of at least 73.2k/day.


I would love to see that broken down, as looking at cryosat et al, it almost appears that ice is retreating from around Svalbard. Very strange.
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