2019 sea ice area and extent data

[gerontocrat]

NSIDC Total Area as at 26 January 2019 (5 day trailing average) 12,450,449  km2

Total Area           12,450,449    km2        368,740    km2   >    2010's average.  617,367    k   >   2018 -159,400    k   <    2000's average.           Total Gain    20    k    Peripheral Seas    4    k   gain Central Seas__    11    k   gain Other Seas___    5    k   gain           Peripheral Seas          Bering _______   -0    k   loss Baffin  Bay____   -5    k   loss Greenland____   -4    k   loss Barents ______    13    k   gain           CAB Seas          Beaufort_____    1    k   gain CAA_________    1    k   gain East Siberian__    2    k   gain Central Arctic_   -1    k   loss           Kara_________    9    k   gain Laptev_______    0    k   gain Chukchi______   -2    k   loss           Other Seas          Okhotsk______    8    k   gain St Lawrence___   -5    k   loss Hudson Bay___    2    k   gain

Area gain 20 k, 7k less than the 2010's average for the day.

Other stuff

GFS indicates that overall the Arctic temperature anomaly remains close to zero and -1 degrees for the next week or more. This disguises the highly variable +ve and -ve anomalies at various times over the various regions of the Arctic.

[Juan C. García]

[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

January 27^th, 2019:
     13,449,609 km², an increase of 79,404 km². 
     2019 is now the 8^th lowest on record (and close to become the 10th.  ).

[Juan C. García]

[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

January 27^th, 2019:
     13,449,609 km², an increase of 79,404 km². 
     2019 is now the 8^th lowest on record (and close to become the 10th.  ).

This abnormal increase, could be a problem with the sensor today?

[AmbiValent]

This abnormal increase, could be a problem with the sensor today?

Last time, grey areas were counted towards extent, so I think that abnormal increase isn't actually there.

[gerontocrat]

JAXA ARCTIC EXTENT 13,449,609 km2（January 27, 2019）

- Extent gain 79k, 77k more than average gain on this day.
- Extent is 8th lowest in the satellite record,
- Freezing to date from minimum is 36 k (0.4%) ABOVE the 10 year average extent gain,
- On average (last 10 years) 89.9 % of the increase in extent from min to max is done.
- On average (last 10 years) 43 days to maximum (11th March)

The outcome from using the 10 year average extent gain from now is a maximum extent of 14.37 million km2 (480k > 2018).

Other Stuff
GFS indicates that overall the Arctic temperature anomaly remains between +1 and -1 degrees for the next week or more. This disguises even more the highly variable +ve and -ve anomalies at various times over the various regions of the Arctic.

The 79k increase is not unprecedented by any means (see graph Arc2 attached) but is a bit of a mystery (see next post).

[gerontocrat]

The 79k increase is not unprecedented. The VISHOP /JAXA image for the day does not show the missing bits as in that from the University of Bremen.

But where did the increase occur? The temperature map for the 27th from GFS shows +ve temperature anomalies for all the areas of the peripheral seas where remaining sea ice extent gain is happening.

So a bit of a mystery.

[Juan C. García]

JAXA ARCTIC EXTENT 13,449,609 km2（January 27, 2019）

- Extent gain 79k, 77k more than average gain on this day.

There has to be a typing mistake here. Maybe 47k more than average gain?

The 79k increase is not unprecedented by any means (see graph Arc2 attached) but is a bit of a mystery (see next post).

Thank you for your answer, Gerontocrat. 

[uniquorn]

amsr2-uhh jan26 and 27 for reference.
Wipneus' charts don't show any drastic changes in the Bering though. https://sites.google.com/site/arcticseaicegraphs/regional

[gerontocrat]

NSIDC Total Area as at 27 January 2019 (5 day trailing average) 12,471,393  km2

Total Area           12,471,393    km2        363,696    km2   >    2010's average.  603,210    k   >   2018 -156,889    k   <    2000's average.           Total Gain    21    k    Peripheral Seas    4    k   gain Central Seas__    2    k   gain Other Seas___    15    k   gain           Peripheral Seas          Bering _______   -5    k   loss Baffin  Bay____   -6    k   loss Greenland____    2    k   gain Barents ______    14    k   gain           CAB Seas          Beaufort_____   -1    k   loss CAA_________    1    k   gain East Siberian__    1    k   gain Central Arctic_   -4    k   loss           Kara_________    8    k   gain Laptev_______    0    k   gain Chukchi______   -3    k   loss           Other Seas          Okhotsk______    17    k   gain St Lawrence___    1    k   gain Hudson Bay___   -3    k   loss

Area gain 20 k, 7k less than the 2010's average for the day.

Other stuff

GFS indicates that overall the Arctic temperature anomaly remains between +1 and -1 degrees for the next week or more. This disguises even more the highly variable +ve and -ve anomalies at various times over the various regions of the Arctic. hence sudden changes in gain and loss in peripheral seas (e.g. Bering, Okhotsk, Baffin, Greenland).

[oren]

JAXA ARCTIC EXTENT 13,449,609 km2（January 27, 2019）

- Extent gain 79k, 77k more than average gain on this day.

There has to be a typing mistake here. Maybe 47k more than average gain?

Not a mistake. Gc quotes the difference from the actual daily average, not from the smooth polynomial approximation of it. The actual daily average fluctuates quite a lot, as can be seen in the chart.
I did wonder in the past what is better to use as quoted baseline, the smoothed or actual average. But luckily for me I'm not the one who has to decide...

[gerontocrat]

JAXA ARCTIC EXTENT 13,449,609 km2（January 27, 2019）

- Extent gain 79k, 77k more than average gain on this day.

There has to be a typing mistake here. Maybe 47k more than average gain?

Not a mistake. Gc quotes the difference from the actual daily average, not from the smooth polynomial approximation of it. The actual daily average fluctuates quite a lot, as can be seen in the chart.
I did wonder in the past what is better to use as quoted baseline, the smoothed or actual average. But luckily for me I'm not the one who has to decide...

The interest to me is that a 10 year average shows such high daily variations. When I made the spreadsheet I thought using a 10 year average would do the smoothing for me. It did not so I chucked in the polynomial (x²) to get a clearer view of the trend.

It just shows that an above average gain on one day coinciding with a very low average day's gain can make one blink - the restless ocean springing a little surprise.

[Feeltheburn]

First time NSID over 14,000,000 km2 for 2019.

14,051,000

I wonder if it will be able to hit 15,000,000 for the first time in years?

[Juan C. García]

The interest to me is that a 10 year average shows such high daily variations.

The same happened to me, so I decided to stop using the original ADS NIPR average and just look at your data... 

[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

January 28^th, 2019:
     13,477,989 km², an increase of 28,380 km².
     2019 is now the 10^th lowest on record.

[Sterks]

JAXA ARCTIC EXTENT 13,449,609 km2（January 27, 2019）

- Extent gain 79k, 77k more than average gain on this day.

There has to be a typing mistake here. Maybe 47k more than average gain?

Not a mistake. Gc quotes the difference from the actual daily average, not from the smooth polynomial approximation of it. The actual daily average fluctuates quite a lot, as can be seen in the chart.
I did wonder in the past what is better to use as quoted baseline, the smoothed or actual average. But luckily for me I'm not the one who has to decide...

I see it as the difference between providing data or information.

[gerontocrat]

JAXA ARCTIC EXTENT 13,477,989 km2（January 28, 2019）

- Extent gain 28k, 15k more than average gain on this day.
- Extent is 10th lowest in the satellite record,
- Freezing to date from minimum is 51 k (0.6%) ABOVE the 10 year average extent gain,
- On average (last 10 years) 90.0 % of the increase in extent from min to max is done.
- On average (last 10 years) 42 days to maximum (11th March)

The outcome from using the 10 year average extent gain from now is a maximum extent of 14.38 million km2 (500k > 2017).

Other Stuff
GFS indicates that overall the Arctic temperature anomaly remains between +1 and -1 degrees for the next week or more. This disguises even more the highly variable +ve and -ve anomalies at various times over the various regions of the Arctic.

[AmbiValent]

Is the data the two-day average? Then the one-day error data will affect both days' published values, but the 28k increase would be real, since it exchanged a day with error-less data with another such day. And tomorrow the error should be gone completely.

[gerontocrat]

NSIDC Total Area as at 28 January 2019 (5 day trailing average) 12,489,322  km2

Total Area           12,489,322    km2        358,854    km2   >    2010's average.  599,319    k   >   2018 -165,841    k   <    2000's average.           Total Gain    18    k    Peripheral Seas    5    k   gain Central Seas__   -6    k   loss Other Seas___    19    k   gain           Peripheral Seas          Bering _______   -7    k   loss Baffin  Bay____   -1    k   loss Greenland____    2    k   gain Barents ______    11    k   gain           CAB Seas          Beaufort_____   -3    k   loss CAA_________    0    k   gain East Siberian__   -0    k   loss Central Arctic_   -7    k   loss           Kara_________    9    k   gain Laptev_______    0    k   gain Chukchi______   -4    k   loss           Other Seas          Okhotsk______    20    k   gain St Lawrence___    1    k   gain Hudson Bay___   -3    k   loss

Area gain 18 k, 5k less than the 2010's average for the day.

Other stuff

GFS indicates that overall the Arctic temperature anomaly remains between +1 and -1 degrees for the next week or more. This disguises even more the highly variable +ve and -ve anomalies at various times over the various regions of the Arctic. hence sudden changes in gain and loss in peripheral seas (e.g. Bering, Okhotsk, Baffin, Greenland).

And now extreme warmth in and beyond the Bering Strait reducing area in the Chukchi, Beaufort and Central Arctic seas as well as the Bering..

[Juan C. García]

[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

January 29^th, 2019:
     13,474,856 km², a drop of -3,133 km².
     2019 is now the 7^th lowest on record.

(Seems that there was a sensor problem on Jan 27^th, that made noise on 27^th and 28^th. With this drop, back to normal).

[gerontocrat]

JAXA ARCTIC EXTENT 13,474,856 km2（January 29, 2019）

Was there a sensor error on 27th Jan ? The 79k increase on that day was not that unusual

- Extent loss 3k, 38k less than average gain on this day.
- Extent is 7th lowest in the satellite record,
- Freezing to date from minimum is 13 k (0.1%) ABOVE the 10 year average extent gain,
- On average (last 10 years) 90.4 % of the increase in extent from min to max is done.
- On average (last 10 years) 41 days to maximum (11th March)

The outcome from using the 10 year average extent gain from now is a maximum extent of 14.34 million km2 (460k > 2017 - record low maximum).

Other Stuff
GFS indicates that overall the Arctic temperature anomaly remains between close to zero for the next 4 days and then rises to over +2 degrees in the following week. The highly variable +ve and -ve anomalies at various times over the various regions of the Arctic may become even more extreme.

[gerontocrat]

As I said on the previous post...

GFS indicates that overall the Arctic temperature anomaly remains between close to zero for the next 4 days and then rises to over +2 degrees in the following week. The highly variable +ve and -ve anomalies at various times over the various regions of the Arctic may become even more extreme.

Here is a GIF of temp anomalies over the Arctic for the next week from GFS to show what I mean

[AmbiValent]

JAXA ARCTIC EXTENT 13,474,856 km2（January 29, 2019）

Was there a sensor error on 27th Jan ? The 79k increase on that day was not that unusual

Yes, it was showing as grey "lack of data" in the images of that day.

[uniquorn]

amsr2-uhh and jaxa vishop images have been corrected for the 27th

[gerontocrat]

amsr2-uhh and jaxa vishop images have been corrected for the 27th

Data on the JAXA file plot_extent_n_v2 (1).csv  not changed yet

[gerontocrat]

NSIDC Total Area as at 29 January 2019 (5 day trailing average) 12,493,988  km2

Total Area           12,493,988    km2        342,152    km2   >    2010's average.  596,583    k   >   2018 -193,996    k   <    2000's average.           Total Gain    5    k    Peripheral Seas   -8    k   loss Central Seas__   -9    k   loss Other Seas___    21    k   gain           Peripheral Seas          Bering _______   -7    k   loss Baffin  Bay____   -4    k   loss Greenland____    1    k   gain Barents ______    1    k   gain           CAB Seas          Beaufort_____   -3    k   loss CAA_________   -0    k   loss East Siberian__   -2    k   loss Central Arctic_   -4    k   loss           Kara_________    4    k   gain Laptev_______    0    k   gain Chukchi______   -4    k   loss           Other Seas          Okhotsk______    22    k   gain St Lawrence___   -1    k   loss Hudson Bay___    0    k   gain

Area gain 5 k, 16k less than the 2010's average for the day.

Other stuff

GFS indicates that overall the Arctic temperature anomaly remains between close to zero for the next 4 days and then rises to over +2 degrees in the following week. The highly variable +ve and -ve anomalies at various times over the various regions of the Arctic may become even more extreme. Hence sudden changes in gain and loss in peripheral seas (e.g. Bering, Okhotsk, Baffin, Greenland).

And now extreme warmth in and beyond the Bering Strait reducing area in the Chukchi, Beaufort and Central Arctic seas as well as the Bering..

[uniquorn]

amsr2-uhh and jaxa vishop images have been corrected for the 27th

Data on the JAXA file plot_extent_n_v2 (1).csv  not changed yet

No, possibly the data was correct. The images faulty. Hamburg and Bremen looked different

[Stephan]

NSIDC Total Area as at 29 January 2019 (5 day trailing average) 12,493,988  km2


         
Other Seas         
Okhotsk______    22    k   gain
St Lawrence___   -1    k   loss
Hudson Bay___    0    k   gain

If I look at the table, in the last two days only the increase in Okhotsk made up for the overall loss of all the other seas...

[Juan C. García]

I am not able to access the ADS NIPR VISHOP website. 
If someone else can do it or wait for Gerontocrat.

https://ads.nipr.ac.jp/vishop/#/extent

[uniquorn]

 edit: showing 29th, not updated

[gerontocrat]

NSIDC Total Area as at 30 January 2019 (5 day trailing average) 12,505,054  km2

Total Area           12,505,054    km2        326,737    km2   >    2010's average.  589,928    k   >   2018 -214,220    k   <    2000's average.           Total Gain    11    k    Peripheral Seas   -15    k   loss Central Seas__   -6    k   loss Other Seas___    32    k   gain           Peripheral Seas          Bering _______   -7    k   loss Baffin  Bay____   -8    k   loss Greenland____    2    k   gain Barents ______   -2    k   loss           CAB Seas          Beaufort_____   -0    k   loss CAA_________   -1    k   loss East Siberian__   -2    k   loss Central Arctic_   -4    k   loss           Kara_________    3    k   gain Laptev_______    1    k   gain Chukchi______   -3    k   loss           Other Seas          Okhotsk______    25    k   gain St Lawrence___    6    k   gain Hudson Bay___    1    k   gain

Area gain 11 k, 15k less than the 2010's average for the day.

Other stuff

GFS indicates that overall the Arctic temperature anomaly remains between close to zero for the next 3 days and then rises to over +2 degrees in the following week. The highly variable +ve and -ve anomalies at various times over the various regions of the Arctic may become even more extreme. Hence sudden changes in gain and loss in peripheral seas (e.g. Bering, Okhotsk, Baffin, Greenland).

And now extreme warmth in and beyond the Bering Strait reducing area in the Chukchi, Beaufort and Central Arctic seas as well as the Bering..

Also of note is that without the Okhotsk area gain of 25k there would be an area loss of 14k on this day. (similar spotted by Stephan yesterday).

[Juan C. García]

[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

January 30^th, 2019:
     13,499,512 km², an increase of 24,656 km².
     
January 31^th, 2019:
     13,479,877 km², a drop of -19,635 km².
     2019 is now the 6^th lowest on record.

[gerontocrat]

JAXA ARCTIC EXTENT 13,479,877 km2（January 31, 2019）

- Extent loss 20k, 63k less than average gain of 43 k on this day.
- Extent is 6th lowest in the satellite record,
- Freezing to date from minimum is 68 k (0.7%) ABOVE the 10 year average extent gain,
- On average (last 10 years) 91.2 % of the increase in extent from min to max is done.
- On average (last 10 years) 39 days to maximum (11th March)

The outcome from using the 10 year average extent gain from now is a maximum extent of 14.26 million km2 (380k > 2017's record low maximum). This is in contrast with using a polynomial trend line projection, which produces a max of around 13.75 million km2 on the 21st February. The Perils of Prediction.

Other Stuff
GFS indicates that overall the Arctic temperature anomaly remains between close to zero for the next 4 days and then rises to over +2 degrees in the following week. The highly variable +ve and -ve anomalies at various times over the various regions of the Arctic may become even more extreme.

[gerontocrat]

NSIDC Total Area as at 31 January 2019 (5 day trailing average) 12,507,869  km2

Total Area           12,507,869    km2        298,987    km2   >    2010's average.  554,389    k   >   2018 -242,036    k   <    2000's average.           Total Gain    3    k    Peripheral Seas   -15    k   loss Central Seas__   -7    k   loss Other Seas___    25    k   gain           Peripheral Seas          Bering _______   -4    k   loss Baffin  Bay____    4    k   gain Greenland____   -1    k   loss Barents ______   -13    k   loss           CAB Seas          Beaufort_____    1    k   gain CAA_________   -1    k   loss East Siberian__   -2    k   loss Central Arctic_   -8    k   loss           Kara_________    3    k   gain Laptev_______    1    k   gain Chukchi______   -2    k   loss           Other Seas          Okhotsk______    16    k   gain St Lawrence___    5    k   gain Hudson Bay___    3    k   gain

Area gain 3 k, 28k less than the 2010's average for the day.

Other stuff

GFS indicates that overall the Arctic temperature anomaly remains between close to zero for the next 3 days and then rises to over +2 degrees in the following week. The highly variable +ve and -ve anomalies at various times over the various regions of the Arctic may become even more extreme. Hence sudden changes in gain and loss in peripheral seas (e.g. Bering, Okhotsk, Baffin, Greenland).

Also of note is that without the Okhotsk area gain of 16k there would be an area loss of 13k on this day (and the previous 3 days). (spotted first by Stephan ).

[Stephan]

If it were not for the Okhotsk Sea we would see a decline in Artic Sea Ice area the last four days...

[Juan C. García]

If it were not for the Okhotsk Sea we would see a decline in Artic Sea Ice area the last four days...

Well, two consecutive declines...

[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.
 
February 1^st, 2019:
     13,426,750 km², a drop of -53,127 km². 
     2019 is now the 4^th lowest on record.

[gerontocrat]

JAXA ARCTIC EXTENT 13,426,750 km2（February 1, 2019）

- Extent loss 53k, 79k less than average gain of 26 k on this day.
- Extent is 4th lowest in the satellite record,
- Freezing to date from minimum is 147 k (1.6%) less than the 10 year average extent gain,
- On average (last 10 years) 91.5 % of the increase in extent from min to max is done.
- On average (last 10 years) 38 days to maximum (11th March)

The Perils of Projections.
The outcome from using the 10 year average extent gain from now is a maximum extent of 14.19 million km2 (310k >2017's record low maximum). Using the last 5 years average extent gain gives a maximum for 14.05 million km2, (170k >2017). This is in contrast with using a polynomial trend line projection, which produces a max of around 13.6 million km2 on the 15th February.

Other Stuff
GFS indicates that overall the Arctic temperature anomaly remains between zero and +3 degrees over the next week. The highly variable +ve and -ve anomalies at various times over the various regions of the Arctic may become even more extreme. This may exaggerate the normal variations in daily change from gains to losses and back to gains that happens at this time of year.

[gerontocrat]

NSIDC Total Area as at 1 February 2019 (5 day trailing average) 12,494,771   km2

Total Area           12,494,771    km2        250,738    km2   >    2010's average.  481,128    k   >   2018 -282,849    k   <    2000's average.           Total Gain   -13    k    Peripheral Seas   -20    k   loss Central Seas__   -5    k   loss Other Seas___    12    k   gain           Peripheral Seas          Bering _______   -2    k   loss Baffin  Bay____    3    k   gain Greenland____   -3    k   loss Barents ______   -19    k   loss           CAB Seas          Beaufort_____    2    k   gain CAA_________    0    k   gain East Siberian__   -3    k   loss Central Arctic_   -6    k   loss           Kara_________    2    k   gain Laptev_______    0    k   gain Chukchi______   -1    k   loss           Other Seas          Okhotsk______    3    k   gain St Lawrence___    7    k   gain Hudson Bay___    2    k   gain

Area LOSS 13 k, 48k less than the 2010's average gain of 35k on this day.

Other stuff

GFS indicates that overall the Arctic temperature anomaly remains between zero and +3 degrees over the next week. The highly variable +ve and -ve anomalies at various times over the various regions of the Arctic may become even more extreme. This may exaggerate the normal variations in daily change from gains to losses and back to gains that happens at this time of year.Hence sudden changes in gain and loss in peripheral seas (e.g.s Bering, Okhotsk, Baffin, Greenland , Barents).

In the last 2 days it is the Barents that is losing area rapidly.

[Juan C. García]

[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.
 
February 2^nd, 2019:
     13,447,260 km², an increase of 20,510 km².
     2019 is the 4^th lowest on record.

[gerontocrat]

JAXA ARCTIC EXTENT 13,447,260 km2（February 2, 2019）

- Extent gain 21k, 18k less than average gain of 39 k on this day.
- Extent is 4th lowest in the satellite record,
- Freezing to date from minimum is 165 k (1.8%) less than the 10 year average extent gain,
- On average (last 10 years) 91.9 % of the increase in extent from min to max is done.
- On average (last 10 years) 37 days to maximum (11th March)

The Perils of Projections.
The outcome from using the 10 year average extent gain from now is a maximum extent of 14.17 million km2 (390k >2017's record low maximum). Using the last 5 years average extent gain gives a maximum for 14.03 million km2, (170k >2017). This is in contrast with using a polynomial trend line projection, which produces a max of around 13.6 million km2 on the 15th February.

Other Stuff
GFS indicates that overall the Arctic temperature anomaly remains between +1 and +3 degrees over the next week. The highly variable +ve and -ve anomalies at various times over the various regions of the Arctic may remain extreme. This may exaggerate the normal variations in daily change in the peripheral seas from gains to losses and back to gains that happens at this time of year.
[/quote]

[gerontocrat]

NSIDC Total Area as at 2 February 2019 (5 day trailing average) 12,466,241   km2

Total Area           12,466,241    km2        180,180    km2   >    2010's average.  367,241    k   >   2018 -334,004    k   <    2000's average.           Total Gain   -29    k    Peripheral Seas   -28    k   loss Central Seas__    1    k   gain Other Seas___   -2    k   loss           Peripheral Seas          Bering _______   -7    k   loss Baffin  Bay____   -1    k   loss Greenland____   -4    k   loss Barents ______   -16    k   loss           CAB Seas          Beaufort_____    4    k   gain CAA_________    1    k   gain East Siberian__   -2    k   loss Central Arctic_   -3    k   loss           Kara_________    1    k   gain Laptev_______   -1    k   loss Chukchi______    0    k   gain           Other Seas          Okhotsk______   -7    k   loss St Lawrence___    6    k   gain Hudson Bay___   -1    k   loss

Area LOSS 29 k, 71k less than the 2010's average gain of 42k on this day.

Other stuff

GFS indicates that overall the Arctic temperature anomaly remains between +1 and +3 degrees over the next week. The highly variable +ve and -ve anomalies at various times over the various regions of the Arctic may become even more extreme. This may exaggerate the normal variations in daily change from gains to losses and back to gains that happens at this time of year.Hence sudden changes in gain and loss in peripheral seas (e.g.s Bering, Okhotsk, Baffin, Greenland , Barents).

As you can see from the last table, all the peripheral seas lost area on this day.

[Juan C. García]

More data, SAT for January. Second lowest Arctic-wide for the last 15 years, all sectors down compared to last three years:

Extend is not showing the increase that it should have after the cold January.
It is 4^th lowest and it could be 3^rd lowest in a couple of days.

[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.
 
February 3^rd, 2019:
     13,428,392 km², a drop of -18,868 km².
     2019 is the 4^th lowest on record.
PS: 2010 has not official value. Average used.

[jdallen]

More data, SAT for January. Second lowest Arctic-wide for the last 15 years, all sectors down compared to last three years:

Extend is not showing the increase that it should have after the cold January.
It is 4^th lowest and it could be 3^rd lowest in a couple of days.

[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.
 
February 3^rd, 2019:
     13,428,392 km², a drop of -18,868 km².
     2019 is the 4^th lowest on record.
PS: 2010 has not official value. Average used.

Here is a relevant question; has extent dropped previously when the overall extent was so low and at the peak of the season?

[gerontocrat]

JAXA ARCTIC EXTENT 13,428,392 km2（February 3, 2019）

- Extent loss 19k, 49k less than average gain of 30 k on this day.
- Extent is 4th lowest in the satellite record,
- Freezing to date from minimum is 214 k (2.3%) less than the 10 year average extent gain,
- On average (last 10 years) 92.2 % of the increase in extent from min to max is done.
- On average (last 10 years) 36 days to maximum (11th March)

The Perils of Projections.
The outcome from using the 10 year average extent gain from now is a maximum extent of 14.12 million km2 (240k >2017's record low maximum). Using the last 5 years average extent gain gives a maximum for 13.99 million km2, (110k >2017). This is in contrast with using a polynomial trend line projection, which produces a max of around 13.55 million km2 on the 10th February - now that would be a surprise.

Other Stuff
GFS indicates that overall the Arctic temperature anomaly remains between +1 and +3 degrees over the next week or so. The highly variable +ve and -ve anomalies at various times over the various regions of the Arctic may remain extreme. This may exaggerate the normal variations in daily change in the peripheral seas from gains to losses and back to gains that happens at this time of year.

In my not very humble opinion a very cold January Arctic-wide can be somewhat irrelevant as far as extent is concerned, as the main Arctic seas are pretty much frozen up by end January in every year. What matters is temperatures, winds and ocean currents at the periphery, especially the Pacific gateway, the Atlantic Front and Baffin Bay. This determines ice gain and loss in these peripheral seas that determine the final outcome of maximum for the year.

[oren]

Here is a relevant question; has extent dropped previously when the overall extent was so low and at the peak of the season?

Yes. It is possible to see in JCG's chart several similar drops around this time of year.

[binntho]

Here is a relevant question; has extent dropped previously when the overall extent was so low and at the peak of the season?

Yes. It is possible to see in JCG's chart several similar drops around this time of year.

The drop in the last 5 days is some 70.000 km2, while 2016 dropped 150.000 km2 in four days starting on the 2nd of February.

[gerontocrat]

Here is a relevant question; has extent dropped previously when the overall extent was so low and at the peak of the season?

Yes. It is possible to see in JCG's chart several similar drops around this time of year.

The drop in the last 5 days is some 70.000 km2, while 2016 dropped 150.000 km2 in four days starting on the 2nd of February.

I think we only notice these variations at this time of year because they are above and below zero.   In any year there are several days or even weeks of daily change of similar or greater amounts above or below the average .

ps: I am looking forward to March when Neven has to decide when to open the 2019 melting thread, and is bombarded with unwanted advice and demands from all sides as daily extent change wobbles around above and below zero.

[gerontocrat]

NSIDC Total Area as at 3 February 2019 (5 day trailing average) 12,431,931   km2

Total Area           12,431,931    km2        102,041    km2   >    2010's average.  232,412    k   >   2018 -387,353    k   <    2000's average.           Total Gain   -34    k    Peripheral Seas   -26    k   loss Central Seas__   -3    k   loss Other Seas___   -5    k   loss           Peripheral Seas          Bering _______   -12    k   loss Baffin  Bay____   -3    k   loss Greenland____   -3    k   loss Barents ______   -7    k   loss           CAB Seas          Beaufort_____    2    k   gain CAA_________    1    k   gain East Siberian__   -0    k   loss Central Arctic_   -8    k   loss           Kara_________    1    k   gain Laptev_______   -1    k   loss Chukchi______   -0    k   loss           Other Seas          Okhotsk______   -10    k   loss St Lawrence___    7    k   gain Hudson Bay___   -2    k   loss

Area LOSS 34 k, 78k less than the 2010's average gain of 44k on this day.

Other stuff

GFS indicates that overall the Arctic temperature anomaly remains between +1 and +3 degrees over the next week or so. The highly variable +ve and -ve anomalies at various times over the various regions of the Arctic may remain extreme.

In my not very humble opinion a very cold January Arctic-wide can be somewhat irrelevant as far as the final resulting maximum is concerned, as the main Arctic seas are pretty much frozen up by end January in every year. What matters is temperatures, winds and ocean currents at the periphery, especially the Pacific gateway, the Atlantic Front and Baffin Bay. This determines ice gain and loss in these peripheral seas that determine the final outcome of maximum for the year.
As you can see from the last table, all the peripheral seas lost area on this day (and the day before).

ps: The very cold January does seem to have bumped up sea ice thickness - presumably this could / will affect the speed of extent and area losses later in the melting season.

[uniquorn]

ps: The very cold January does seem to have bumped up sea ice thickness

Yes, should help a bit.

[Dharma Rupa]

ps: I am looking forward to March when Neven has to decide when to open the 2019 melting thread, and is bombarded with unwanted advice and demands from all sides as daily extent change wobbles around above and below zero.

When did you stop beating your wife?

[Neven]

ps: I am looking forward to March when Neven has to decide when to open the 2019 melting thread, and is bombarded with unwanted advice and demands from all sides as daily extent change wobbles around above and below zero.

Yes, that's my favourite time of year! 

[jdallen]

Here is a relevant question; has extent dropped previously when the overall extent was so low and at the peak of the season?

Yes. It is possible to see in JCG's chart several similar drops around this time of year.

The drop in the last 5 days is some 70.000 km2, while 2016 dropped 150.000 km2 in four days starting on the 2nd of February.

I think we only notice these variations at this time of year because they are above and below zero.   In any year there are several days or even weeks of daily change of similar or greater amounts above or below the average .

ps: I am looking forward to March when Neven has to decide when to open the 2019 melting thread, and is bombarded with unwanted advice and demands from all sides as daily extent change wobbles around above and below zero.

Serves me right for trying to reply on my phone instead of sitting down where I can type.

My curiosity is more nuanced than just drops at this time of year.  I'm also reflecting on the size of the pack when the drop occurs.  That we've had similar drops at this time of year is no surprise to me.  I'm wondering, going back, what similar events we've had at similar levels of coverage.

So, there is a timing issue, but it has more to do with when the pack has passed the current threshold in the past, and what sort of volatility it had at those junctures. 

What's sticking in my head are questions actually more oriented towards ice quality and total heat content, which are probably unanswerable with the instrumentation currently available.