2016 sea ice area and extent data

[Wipneus]

Here is the shadow CT-area report based on calibrated F18 NSIDC sea ice concentration data:

day  CT-date       NH               SH                Global
Wed 2016.7370  +78.0  3.351381  +73.3 14.137631  +151.4 17.489012
Thu 2016.7397  +75.4  3.426748   -3.2 14.134479   +72.2 17.561227
Fri 2016.7425  +60.1  3.486840 -183.9 13.950626  -123.8 17.437466
Sat 2016.7452  +40.3  3.527093  -53.3 13.897350   -13.0 17.424443

CAB: +40k, CAA:+17k

Shadow NSIDC extent was 5.1739M increasing +31.3k. CAB: +47k, ESS: -26k.

Then there is the new delta map attached.

[magnamentis]

Here is the shadow CT-area report based on calibrated F18 NSIDC sea ice concentration data:

day  CT-date       NH               SH                Global
Wed 2016.7370  +78.0  3.351381  +73.3 14.137631  +151.4 17.489012
Thu 2016.7397  +75.4  3.426748   -3.2 14.134479   +72.2 17.561227
Fri 2016.7425  +60.1  3.486840 -183.9 13.950626  -123.8 17.437466
Sat 2016.7452  +40.3  3.527093  -53.3 13.897350   -13.0 17.424443

CAB: +40k, CAA:+17k

Shadow NSIDC extent was 5.1739M increasing +31.3k. CAB: +47k, ESS: -26k.

Then there is the new delta map attached.

now that the CAB is more or less covered by ice ( easy freezing ) the refreeze apparently is slowing down and i'd not be surprised to see some setbacks in the days and/or weeks to come, especially considering the heavy blows that are predicted from the pacific as well as the atlantic side. interesting to watch in any case and if the water is as warm as is shown in some maps even more so.

[Darvince]

I don't think we'll see any area setbacks because the CAB is still so low concentration for whatever reason

[Wipneus]

Here is the shadow CT-area report based on calibrated F18 NSIDC sea ice concentration data:

day  CT-date       NH               SH                Global
Thu 2016.7397  +75.4  3.426748   -3.2 14.134479   +72.2 17.561227
Fri 2016.7425  +60.1  3.486840 -183.9 13.950626  -123.8 17.437466
Sat 2016.7452  +40.1  3.526912  -53.4 13.897204   -13.3 17.424116
Sun 2016.7479  +61.9  3.588829  -29.6 13.867653   +32.4 17.456482

CAB: +55k.

Shadow NSIDC extent is now 5.1748M up +1.0k. CAA was up +17k, ESS down -19k.

The daily changes are summarized in the attached delta map.

[Wipneus]

Here is the shadow CT-area report based on calibrated F18 NSIDC sea ice concentration data:

day  CT-date       NH               SH                Global
Fri 2016.7425  +60.1  3.486840 -183.9 13.950626  -123.8 17.437466
Sat 2016.7452  +40.1  3.526912  -53.4 13.897204   -13.3 17.424116
Sun 2016.7479  +61.7  3.588563  -29.7 13.867477   +31.9 17.456040
Mon 2016.7507  +68.2  3.656714   +7.8 13.875320   +76.0 17.532034

CAB:+62k, ESS:+16k

Shadow NSIDC extent is now 5.1873M up  +12.5k. ESS increased by +26k.

The delta map that goes with these figures is attached.

This was the last daily extent and area report (based on NSIDC sea ice concentration) of the season. During the freezing season I probably will report once every week or two-weeks what my shadow CT-area figures are.

[Tor Bejnar]

This was the last daily extent and area report (based on NSIDC sea ice concentration) of the season. During the freezing season I probably will report once every week or two-weeks what my shadow CT-area figures are.

Thank you so much, Wipneus, for all you offer this community. 
Enjoy your week or two 'vacation'!

[Pmt111500]

This was the last daily extent and area report (based on NSIDC sea ice concentration) of the season. During the freezing season I probably will report once every week or two-weeks what my shadow CT-area figures are.

Thanks Wipneus, this is quite nice of you, to have continuity on the numbers is pretty essential for stats. F.e. I commonly use sliding averages of one week to get rid of random elements of weather, so getting the daily values is very nice, be it once a month or more often. Heck, even the moon might have some effect on the freezing process so even longer averages could be used. The satellite orbits and the times of their swath is another potential source of error, but the satellite problem should be smaller during constant sun or constant darkness. I'm fairly interested on when the freezing process stalls and if it does so, are we in a (warmer) repeat of 2006-7 winter?

[budmantis]

Thanks Wipneus for your contribution to all of us here at the Forum. Greatly appreciated!

[BornFromTheVoid]

Update for the week to October 1st

The current 5 day trailing average is on 5,192,000km2 while the 1 day extent is at 5,281,000km2.

(All the following data is based on a trailing 5 day average)
The daily anomaly (compared to 81-10) is at -1,596,000km2, a decrease from -1,747,000km2 last week. The anomaly compared to the 07, 11 and 12 average is at +776,000km2, an increase from +539,000km2 last week. We're currently 6th lowest on record, the same as last week.



The average daily change over the last 7 days was +71.7k/day, compared to the long term average of +50.1k/day, and the 07, 11 and 12 average of +37.8k/day.
The average long term change over the next week is +92.1k/day, with the 07, 11, and 12 average being +67.7k/day.



The extent increase so far this October is the 4th smallest on record. To achieve the largest gain, an increase of at least 139.4k/day is required (requiring at least +146.1k/day with with single day values), while the smallest gain requires an increase of less than 51.1k/day (+51.6k/day with single day values) and an average gain requires an increase of 90.7k/day ( 94.0k/day with single day values).



(Note that the graphs above don't show 2016 as there's only 1 point on each graph)

The extent change in September was the 3rd largest on record, while the average extent was the 3rd lowest on record.

[Tor Bejnar]

BFTV:
Could you post the full September "NSIDC Extent" graph and a graph including September in "Refreeze: 7 Day Extent Change" (as you did for "Cumulative Extent Change").  (After I figured out why I couldn't find 2016 data points, I read your Note.  I guess I'm not a dumb as I look, nor as bright as I claim.)

Cute: 3rd largest extent change and 3rd lowest average extent.

[BornFromTheVoid]

BFTV:
Could you post the full September "NSIDC Extent" graph and a graph including September in "Refreeze: 7 Day Extent Change" (as you did for "Cumulative Extent Change").  (After I figured out why I couldn't find 2016 data points, I read your Note.  I guess I'm not a dumb as I look, nor as bright as I claim.)

Cute: 3rd largest extent change and 3rd lowest average extent.

No problem, I'll post the latest graphs too now that 2016 is visible with 2 data points.

[Wipneus]

Four days of area (shadow CT-area that is) drops in a row:

day  CT-date       NH               SH                Global
Mon 2016.7507  +68.2  3.656771   +7.8 13.875301   +76.0 17.532072
Tue 2016.7534 +134.0  3.790730  +62.6 13.937874  +196.5 17.728604
Wed 2016.7562  -83.5  3.707184  +69.8 14.007681   -13.7 17.714865
Thu 2016.7589  -27.3  3.679907  +43.1 14.050775   +15.8 17.730682
Fri 2016.7616  -63.6  3.616354  -55.4 13.995418  -118.9 17.611772
Sat 2016.7644   -2.4  3.613994  -24.6 13.970800   -27.0 17.584794


All in the CAB. Other area calculations (Jaxa, Uni Hamburg) do not show such big drops, just a slowdown in growth.

Since extent continues to grow, the compactness for the NSIDC sea ice concentration drops to remarkable low values. See the attached graph.

The attached delta map now spans 4 days, showing were that concentration dropped.

[Shared Humanity]

Is this real? If so, it is terrifying! Could the dispersed ice and repeated cyclones over the past 2 months have brought warm water to the surface in the CAB?

[plinius]

It is near impossible that this is melt of any kind. Yes, air temperatures are far too high in this region, but this still means -5 to -12 Celsius or so. Enough to offset eventual heat flow from below (this is not the periphery, where you would have 5Celsius water readily available directly near the surface, heat flow from dozens of meters depth is severely limited). However, during the past few days the area was under a divergent pressure field with a cyclone, so both pointing for some divergence in the ice.

[jdallen]

It is near impossible that this is melt of any kind. Yes, air temperatures are far too high in this region, but this still means -5 to -12 Celsius or so. Enough to offset eventual heat flow from below (this is not the periphery, where you would have 5Celsius water readily available directly near the surface, heat flow from dozens of meters depth is severely limited). However, during the past few days the area was under a divergent pressure field with a cyclone, so both pointing for some divergence in the ice.

I'll disagree somewhat - but your core thinking is still valid.

My objection goes to the quality of the ice being formed.  If it is mostly nilas forming around snowfall forming into relatively thin pans, that ice could cover very wide extent and still be quite vulnerable.

Add significant wind and wave action, it could both melt some of what is really a very vulnerable "skin" of ice as a result of mixing, and stack it up into thicker masses, but with less overall coverage.

Add to this, the incredible heat in the peripheral seas, which *still* will annihilate any ice that gets driven into it in fairly short order, and I'm not surprised by what really are very modest declines.

[Pmt111500]

Yea, one could think numbers of the speeds of frreezing and melting are governed by the orbits of the measuring satellites and/or the moon cycles. Looking at a whole year there's no strong dependence between these and moon, though, and still the correlation breaks (regularly or irregularly, I haven't checked).

Funny though you often get these kinds of cycles lasting ~half a lunar period. (x tick = 1 week), here it looks like full and new moons would be the bottoms of the freezing speed and quarters would see the fastest growth.

(Modded soon after; the full/new moon period would kind of make sense since the tides are strongest here, disturbing the water, the Arctic Ocean though has smaller tides than other oceans due the orbit of the moon. But the above still applies, the swings are not regular, or at least I haven't found a proper correlation here.)

[plinius]

@jdallen - I think we are in full agreement, and also think we were all talking about a slightly different region each - my focus was the slight area decrease within the pack, while you focus on the rim. I should have mentioned the nilas too - to my knowledge sometimes misidentified as open water by some evaluations (or not so misidentified, given how thin it is).

@Pmt: I think you just produced one marvellous example of red noise. If you want my bet, I would guess that your oscillations are chiefly caused by your smoothing period. You appear to be using a 7-day smoothing, so you will necessarily see in your result a pseudo-period of about 7-20 days (typically 14). No worries, scientists get that wrong, and the red noise fallacy is particularly popular with climate deniers (hint: "30-60 year climate periods..."). I'd get acquainted with that - it's a useful thing to know when engaging with a denier.

[BornFromTheVoid]

Update for the week to October 8th

The current 5 day trailing average is on 5,350,000km2 while the 1 day extent is at 5,405,000km2.

(All the following data is based on a trailing 5 day average)
The daily anomaly (compared to 81-10) is at -2,083,000km2, an increase from -1,596,000km2 last week. The anomaly compared to the 07, 11 and 12 average is at +460,000km2, a decrease from +776,000km2 last week. We're currently 3rd lowest on record, up from 6th lowest last week.



The average daily change over the last 7 days was +22.6k/day, compared to the long term average of +92.1k/day, and the 07, 11 and 12 average of +67.7k/day.
The average long term change over the next week is +94.0k/day, with the 07, 11, and 12 average being +88.0k/day.



The extent increase so far this October is the smallest on record. To achieve the largest gain, an increase of at least 174.9k/day is required (requiring at least +188.8k/day with with single day values), while the smallest gain requires an increase of less than 59.8k/day (less than 62.9k/day with single day values) and an average gain requires an increase of 111.4k/day (119.4k/day with single day values).

[Tor Bejnar]

...


The extent increase so far this October is the smallest on record. ...

The "7 Day Extent Change" graph shows we are are in record low change territory for the day-of-year.  Given this is at the beginning of the month, the extent increase this month is smallest on record.  I will watch closely how the 2016 curve progresses on this graph; over the next two weeks, both 2007 and 2012 had significantly increased extent change.

If I understand the legend correctly, "Max" shows the maximum melt change (from previous day [or 5 day period?]), or in this season, the minimum freeze [rate].

[jdallen]

Update for the week to October 8th
<snip>

These graphs, in particular the 2nd one showing 7 day extent change, are *really* *REALLY* disturbing.

[BornFromTheVoid]

...


The extent increase so far this October is the smallest on record. ...

The "7 Day Extent Change" graph shows we are are in record low change territory for the day-of-year.  Given this is at the beginning of the month, the extent increase this month is smallest on record.  I will watch closely how the 2016 curve progresses on this graph; over the next two weeks, both 2007 and 2012 had significantly increased extent change.

If I understand the legend correctly, "Max" shows the maximum melt change (from previous day [or 5 day period?]), or in this season, the minimum freeze [rate].

It's the change in extent between the current day shown in the graph and 1 week/7 days earlier. It's a longer term view of change and the seasonal cycles in the rate of change.

With all these graphs, they use the 5 day trailing average, like the NSIDC use and then water metrics are applied. The maximumin this instance is the the smallest extent change over the past 7 days. (I forgot to alter the legend from the melt season version, when max refers to the largest extent drop over the last 7 days. Will correct on the next update!)

[BornFromTheVoid]

Update for the week to October 15th

The current 5 day trailing average is on 5,570,000km2 while the 1 day extent is at 5,736,000km2.

(All the following data is based on a trailing 5 day average)
The daily anomaly (compared to 81-10) is at -2,520,000km2, an increase from -2,083,000km2 last week. The anomaly compared to the 07, 11 and 12 average is at +63,000km2, a decrease from +460,000km2 last week. We're currently 3rd lowest on record, the same as last week.



The average daily change over the last 7 days was +31.4k/day, compared to the long term average of +94.0k/day, and the 07, 11 and 12 average of +88.0k/day.
The average long term change over the next week is +93.4k/day, with the 07, 11, and 12 average being +141.3k/day.



The extent increase so far this October is the smallest on record. To achieve the largest gain, an increase of at least 237.6k/day is required (requiring at least +259.7k/day with with single day values), while the smallest gain requires an increase of less than 72.2k/day (less than 70.7k/day with single day values) and an average gain requires an increase of 146.4k/day (155.4k/day with single day values).

[Tor Bejnar]

This has been a phenomenal week!  I wonder when it will break. 

[Wipneus]

Here is an update of the shadow CT-area data based on calibrated F18 NSIDC sea ice concentration data for the last two weeks:


NSIDC day  CT-date       NH               SH                Global
2016-10-02 2016.7562  -83.5  3.707184  +69.8 14.007681   -13.7 17.714865
2016-10-03 2016.7589  -27.3  3.679907  +43.1 14.050775   +15.8 17.730682
2016-10-04 2016.7616  -63.6  3.616354  -55.4 13.995418  -118.9 17.611772
2016-10-05 2016.7644   -2.4  3.613957  -24.0 13.971381   -26.4 17.585338
2016-10-06 2016.7671  +59.6  3.673516  -58.1 13.913327    +1.5 17.586843
2016-10-07 2016.7699   -5.8  3.667742  -96.9 13.816444  -102.7 17.484186
2016-10-08 2016.7726  +82.9  3.750600   +7.4 13.823845   +90.3 17.574445
2016-10-09 2016.7753   +2.6  3.753235  -35.4 13.788411   -32.8 17.541646
2016-10-10 2016.7781  +77.5  3.830728   +9.0 13.797398   +86.5 17.628126
2016-10-11 2016.7808  +74.3  3.905014  -42.2 13.755224   +32.1 17.660238
2016-10-12 2016.7836  +88.5  3.993525 -108.4 13.646846   -19.9 17.640371
2016-10-13 2016.7863  +46.1  4.039592  -84.4 13.562492   -38.3 17.602084
2016-10-14 2016.7890  +15.7  4.055252 -129.1 13.433388  -113.4 17.488640
2016-10-15 2016.7918  +88.8  4.144047 -104.9 13.328501   -16.1 17.472548
2016-10-16 2016.7945  +49.1  4.193128  -37.2 13.291345   +11.9 17.484473

[Wipneus]

CT-area calculation has some quirks which I have discussed before in this thread. The quirks are bad enough to influence year-to-year compares and compares to (NSIDC) extent.  Therefore I prefer my own calculation of area from NSIDC sea ice concentration which I simply refer to as "NSIDC area".

My "NSIDC area" , second at the September minimum (well behind 2012) is now clearly record low. Here are the low ten for the 16th of October:

2008-10-16 5.791259
2005-10-16 5.703641
2014-10-16 5.589762
2015-10-16 5.423625
2010-10-16 5.409079
2009-10-16 5.015004
2011-10-16 4.710685
2012-10-16 4.516444
2007-10-16 4.343980
2016-10-16 4.191935


 

[Tealight]

My "NSIDC area" , second at the September minimum (well behind 2012) is now clearly record low.

Same in my calculations. 2016 is 1 million km² below my calculated 2007-2015 ice concentration average.

Attached is an concentration anomaly map.
Red= lower than average ice concentration
Blue= higher than average ice concentration

[seaicesailor]

Uncharted territory as usual

[A-Team]

wip, any chance you could remind us how these numbers should be rounded off to be in line with their actual accuracy / errors in determination? The ones above go below parts per million, a square km. Should they be rounded off to two decimal points or is that already delusional?

2008-10-16 5.79
2005-10-16 5.70
2014-10-16 5.59
2015-10-16 5.42
2010-10-16 5.41
2009-10-16 5.02
2011-10-16 4.71
2012-10-16 4.52
2007-10-16 4.34
2016-10-16 4.19

Are 2013 and 2006 available for the sake of completeness (as the top ten is confined to recent years)?

2016-10-16 4.19
2015-10-16 5.42
2014-10-16 5.59
2012-10-16 4.52
2011-10-16 4.71
2010-10-16 5.41
2009-10-16 5.02
2008-10-16 5.79
2007-10-16 4.34
2005-10-16 5.70

[Shared Humanity]

That concentration anomaly map I believe shows evidence of the cyclones that occurred throughout the 2nd half of this melt season. In the CAA, we see the effect of the "Garlic Press" as MYI, broken into relatively small flows, was pushed into the CAA. In the CAB we still see clear evidence of the dispersion that occurred due to the cyclones.

[Pmt111500]

Using the ShCT SIA numbers provided by Wipneus, thanks again. Here's more possible red noise from NH and the similar graph from SH on top of each other. As can be seen they do not align w/ each other AT ALL, so this isn't (at least entirely) due moon. And at other times of the year the ups and downs don't show as clearly as here when the daily freeze thaw cycle is nearly balanced. And it's entirely possible that this is just red noise, like plinius said. I guess there's very little if anything to be learned from this, so I guess it's better to stop wondering this in this thread.

[A-Team]

In the CAA, we see the effect of the "Garlic Press" as MYI, broken into relatively small flows, was pushed into the CAA

Here is an update on that, for Sept 1st through Oct 18th. Since there is so little old thick ice left in the lower central Arctic to being with -- and that is the ice predominantly subjected to garlic press extrusion -- this flux is having a significant impact as the hardest ice to melt is 'offloaded' to heat provided by Northwest Passage waters.

The time series below shows the region between Banks Island and northwest Greenland, so includes M'Clure to Nares Strait but not the Fram (for that, see 2nd animation with hycom at 6 day offset to Oct 20th). To help the eye track floe motion, ice of 100% concentration (according to UHH AMSR2) is recolored green.

[timallard]

Looks below this day for all previous years just showing 2007,2011, 2015 & this year.

Greenland shows a big jump in mass for the SE up to 2015 an above average year: http://www.dmi.dk/en/groenland/maalinger/greenland-ice-sheet-surface-mass-budget/

[BornFromTheVoid]

Update for the week to October 22nd

The current 5 day trailing average is on 6,279,000km2 while the 1 day extent is at 6,583,000km2.

(All the following data is based on a trailing 5 day average)
The daily anomaly (compared to 81-10) is at -2,466,000km2, a decrease from -2,520,000km2 last week. The anomaly compared to the 07, 11 and 12 average is at -217,000km2, a change from +63,000km2 last week. We're currently lowest on record, up from 3rd lowest last week.



The average daily change over the last 7 days was +101.3k/day, compared to the long term average of +93.4k/day, and the 07, 11 and 12 average of +141.3k/day.
The average long term change over the next week is +81.1k/day, with the 07, 11, and 12 average being +172.2k/day.



The extent increase so far this October is the smallest on record. To achieve the largest gain, an increase of at least 343.6k/day is required (requiring at least +398.4k/day with with single day values), while the smallest gain requires an increase of less than 49.7k/day (less than 20.4k/day with single day values) and an average gain requires an increase of 181.4k/day (189.8k/day with single day values).

[Tealight]

In order to end our critical data gap for Sea Ice Area I reworked my website layout, improved maps, added graphs and data files. My calculations are very similar to Wipneus "NSIDC Area" which itself are an improvement over very similar Cryosphere Today area numbers. Compared to Wipneus my values are within 1% error. The main difference should be masking out noise from coastlines. However everything on my website is calculated by my code to make years comparable.

As before everything will be updated automatically at 18:00 GMT.

Arctic:
https://sites.google.com/site/cryospherecomputing/daily-data
Antarctic:
https://sites.google.com/site/cryospherecomputing/daily-data-antarctic
Data in csv format:
https://sites.google.com/site/cryospherecomputing/files

[charles_oil]

Thanks Tealight - easy to see and nice that its consistent / contiguous data.

[BornFromTheVoid]

Update for the week to October 29th

The current 5 day trailing average is on 7,028,000km2 while the 1 day extent is at 7,111,000km2.

(All the following data is based on a trailing 5 day average)
The daily anomaly (compared to 81-10) is at -2,284,000km2, a decrease from -2,466,000km2 last week. The anomaly compared to the 07, 11 and 12 average is at -673,000km2, an increase from -217,000km2 last week. We're currently lowest on record, the same as last week.



The average daily change over the last 7 days was +107.0k/day, compared to the long term average of +81.1k/day, and the 07, 11 and 12 average of +172.2k/day.
The average long term change over the next week is +82.7k/day, with the 07, 11, and 12 average being +134.4k/day.



The extent increase so far this October is the 6th smallest on record. To achieve the largest gain, an increase of at least 1171.2k/day is required (requiring at least +3803.4k/day with with single day values), while the smallest gain requires a loss more than than 151.1k/day (more than 604.1k/day with single day values) and an average gain requires an increase of 441.8k/day (1372.4k/day with single day values).

[diablobanquisa]

https://nsidc.org/data/seaice_index/

[Tor Bejnar]

https://nsidc.org/data/seaice_index/


...

This graph, showing greater variability during the last decade than during the earlier two, reminds me of a sentence in the October weather/climate summary from Dr. Master's blog post by Bob Henson:

... While the average amount of summer rainfall across the Southeast hasn’t changed in recent decades, the year-to-year variability has significantly increased. ...

One difference, of course, is that October Arctic sea ice extent is on a downward trend.

[Wipneus]

Playing/studying graphing with Python, here is a rough graph of global (NH+SH) sea ice area, calculated from NSIDC sea ice concentration.

Guess which line is 2016. The second max peak around November is nearly completely gone. Total Terra Incognito.

[DrTskoul]

 

[Tealight]

Playing/studying graphing with Python, here is a rough graph of global (NH+SH) sea ice area, calculated from NSIDC sea ice concentration.

Guess which line is 2016. The second max peak around November is nearly completely gone. Total Terra Incognito.

Damn you are 2 hours ahead of me. I better come up with a new graph. The complete avoidance of the highest peak is really impressive. Currently 2016 is around 2.8 million km² below the previous record low.

[meljay14]

Thank you Wipneus and Tealight for these graphs.

I have been on this forum for a few months but this is my first post. Will probably be a fairly chronic lurker, as although the daughter, sister and mother of scientists, I am not one myself.

But I would like to thank everyone for all the amazing information and graphics. Somebody on another thread spoke about the five stages of grieving, and that's certainly where I find myself in relation to climate change and other forms of anthropogenic global ecosystem damage - just going back and forth between anger, depression and acceptance.

One of the forms that acceptance takes, for me, is the thought that if I'm going to live in such dark times, I might as well at least find it interesting. All the information and insights on this form certainly help with that.

[abbottisgone]

"I'll have a bourbon on the rocks thanks 

Better make it a double,... on the double while you're at it 

https://www.youtube.com/watch?v=sM7GSi7ZuIc&list=PLCCBg8Rr0T3EQiZSscr6CZVWrL51vdLvF

 - let's go out with a laugh, whaddya say?"

[Pmt111500]

I'd say the grey area of the the blackbody-earth has experienced some growth. I rather wish we could use the void in deniers' brains as heat sink, but I don't know how to tap those in

[Sleepy]

Hmm, that void is probably somewhere right in the middle of atmospheric pressure and perfect vacuum, so heat would only radiate right through.

[Pmt111500]

Hmm, that void is probably somewhere right in the middle of atmospheric pressure and perfect vacuum, so heat would only radiate right through.

True, this is what happens when you don't think puns through  .

[Wipneus]

More practice in graphing with Python.

Global extent about 2 million below the lowest for the day. Global area even more.

[charles_oil]

I'll have a bourbon on the rocks thanks 

Sorry - Abbott - not enough "rocks" to spare just now - they're all needed up north !

[BornFromTheVoid]

Update for the week to November 5th

The current 5 day trailing average is on 7,511,000km2 while the 1 day extent is at 7,858,000km2.

(All the following data is based on a trailing 5 day average)
The daily anomaly (compared to 81-10) is at -2,380,000km2, an increase from -2,284,000km2 last week. The anomaly compared to the 07, 11 and 12 average is at -1,130,000km2, an increase from -673,000km2 last week. We're currently lowest on record, the same as last week.



The average daily change over the last 7 days was +69.0k/day, compared to the long term average of +82.7k/day, and the 07, 11 and 12 average of +134.4k/day.
The average long term change over the next week is +61.7k/day, with the 07, 11, and 12 average being +77.8k/day.



The extent increase so far this November is the 17th largest on record. To achieve the largest gain, an increase of at least 98.5k/day is required (at least +91.9k/day with with single day values), while the smallest gain requires an increase of less than 31.1k/day (less than 18.7k/day with single day values) and an average gain requires an increase of 65.9k/day (56.5k/day with single day values).



The extent change in October was the 2nd smallest on record, while the average extent was the 3rd lowest on record.

[Wipneus]

High time for an an update of the shadow CT-area data based on calibrated F18 NSIDC sea ice concentration data for the last three weeks:


NSIDC day  CT-date       NH               SH                Global
2016-10-16 2016.7945  +49.7  4.193738  -38.1 13.290352   +11.5 17.484090
2016-10-17 2016.7973  +44.2  4.237919 -187.4 13.102945  -143.2 17.340864
2016-10-18 2016.8000  +26.2  4.264125  -65.9 13.037066   -39.7 17.301191
2016-10-19 2016.8027 +152.5  4.416624  +34.5 13.071525  +187.0 17.488149
2016-10-20 2016.8055 +181.0  4.597574  -14.1 13.057376  +166.8 17.654950
2016-10-21 2016.8082 +114.2  4.711817  -47.2 13.010159   +67.0 17.721976
2016-10-22 2016.8110  +59.3  4.771165   -9.1 13.001009   +50.2 17.772174
2016-10-23 2016.8137 +138.8  4.909947  -77.6 12.923422   +61.2 17.833369
2016-10-24 2016.8164 +148.7  5.058676 -134.5 12.788879   +14.2 17.847555
2016-10-25 2016.8192 +133.8  5.192513  +40.4 12.829299  +174.3 18.021812
2016-10-26 2016.8219  -13.0  5.179495 -142.0 12.687301  -155.0 17.866796
2016-10-27 2016.8247  +21.0  5.200499 -105.6 12.581686   -84.6 17.782185
2016-10-28 2016.8274  +84.3  5.284816  +11.7 12.593391   +96.0 17.878207
2016-10-29 2016.8301  +26.1  5.310950  -87.8 12.505591   -61.7 17.816541
2016-10-30 2016.8329  +10.6  5.321560 -149.2 12.356376  -138.6 17.677936
2016-10-31 2016.8356  +31.8  5.353336 -117.4 12.239007   -85.6 17.592343
2016-11-01 2016.8384 +118.3  5.471602  -16.3 12.222696  +102.0 17.694298
2016-11-02 2016.8411 +152.7  5.624340 -116.0 12.106692   +36.7 17.731032
2016-11-03 2016.8438 +178.0  5.802314 -132.5 11.974203   +45.5 17.776517
2016-11-04 2016.8466 +117.7  5.919982 -208.7 11.765479   -91.1 17.685461
2016-11-05 2016.8493 +197.5  6.117497 -151.1 11.614377   +46.4 17.731874
2016-11-06 2016.8521 +205.9  6.323378 -247.3 11.367067   -41.4 17.690445


Today's double century gain get beaten by a two and a half century gainloss in the Antarctic ocean, causing global area to drop. CT-global area is normally above 22M at this date, so the anomaly would be a staggering -4.4M, lowest in the record.