2015 sea ice area and extent data

[Jim Pettit]

IJIS Extent:

13,665,311 km2 (31 March)

Down 276,749 km2 (1.98%) from 2015 maximum-to-date of 13,942,060 km2 on 15 February.

10,487,856 km2 above record minimum extent of 3,177,455 km2 (16 September 2012).

Down 29,829 km2 from previous day.

Down 168,096 km2 over past seven days (daily average: -24,014 km2).

Down 153,006 km2 for the month of March (daily average: -4,936 km2).

608,479 km2 below 2000s average for this date.

493,411 km2 below 2010s average for this date.

211,863 km2 below 2014 value for this date.

865,496 km2 below 2012 value for this date.

Lowest March average on record.

2nd lowest value for the date.

26 days this year (28.89% year-to-date) have recorded the lowest daily extent.

19 days (21.11%) have recorded the second lowest.

19 days (21.11%) have recorded the third lowest.

64 days (71.11%) in total have been among the three lowest on record.

CT Area:

12,990,146 km2 (31 March [Day 0.2439])

Down 284,410 km2 (2.14%) from 2015 maximum-to-date of 13,274,555 km2 on 17 February [Day 0.1288].

10,756,136 km2 above record minimum area of 2,234,010 km2 (14 September 2012).

Up 35,411 km2 from previous day.

Up 39,786 km2 over past seven days (daily average: 5,684 km2).

Down 88,965 km2 for the month of March (daily average: -2,870 km2).

399,930 km2 below 2000s average for this date.

330,484 km2 below 2010s average for this date.

118,359 km2 below 2014 value for this date.

716,258 km2 below 2012 value for this date.

3rd lowest March average on record.

4th lowest value for the date.

7 days this year (7.78% year-to-date) have recorded the lowest daily area.

8 days (8.89%) have recorded the second lowest.

6 days (6.67%) have recorded the third lowest.

21 days in total (23.33%) have been among the lowest three on record.

[Wipneus]

With NSIDC's sea ice concentration from today, I expect the following changes of  CT-area:

Wed       12.990146
Thu -0.9 12.989282
Fri +3.3 12.992571

Today was supposed to:

Wed +35.6 12.990381

But instead:
Wed +35.4 12.990146

[epiphyte]

Did you forget to subtract Superman's fortress of solitude? It's an easy one to miss...

[Wipneus]

Bringing out a new release and within a few days forced to announce another one is a nightmare. Happened to Jaxa GCOM-W1 data service:

This is the help desk of the GCOM-W1 Data Providing Service.

After the AMSR2 product updates (Version 2.0) on March 26, 2015,
we have found inadequate parameter settings in the Level (L)-1
processing system.
To solve these issues, we are going to release all the updated Version
2.1 AMSR2 product (L1, L2, and L3)
again on April 3, 2015.

We apologize to all AMSR2 data users for this inconvenience.

For those who already acquired the Version 2.0 products,
we strongly recommend to download Version 2.1 products and replace older
versions with them.

Major product changes associated with this update are as follows.

  Release of updated AMSR2 products (Version 2.1)
?<http://gcom-w1.jaxa.jp/contents/150403_Ver2.1_release_e.pdf>

If you have any questions regarding the AMSR2 products or this website,
please contact our Help Desk as customer service.
Please feel free to ask if there is anything about which you are uncertain.

We hope that you will actively use our website for the years to come.

Sincerely yours,

Help Desk / GCOM-W1 Data Providing Service

This does influence the reliability of my "home brew" data and probably also the Jaxa extent data (formerly known as IJIS extent data) of the last few days.

[Wipneus]

With the latest NSIDC's sea ice concentration , I expect the following changes of  CT-area:



Thu       12.990585
Fri +3.2 12.993751
Sat -11.7 12.982079


predicted for Thursday:

Thu -0.9 12.989282

actual:
Thu  +0.4  12.990585

[Jim Pettit]

IJIS Extent:

13,610,885 km2 (02 April)

Down 331,175 km2 (2.38%) from 2015 maximum-to-date of 13,942,060 km2 on 15 February.

10,433,430 km2 above record minimum extent of 3,177,455 km2 (16 September 2012).

Down 36,770 km2 from previous day.

Down 273,019 km2 over past seven days (daily average: -39,003 km2).

Down 54,426 km2 for the month of April (daily average: -27,213 km2).

606,131 km2 below 2000s average for this date.

508,284 km2 below 2010s average for this date.

246,607 km2 below 2014 value for this date.

862,912 km2 below 2012 value for this date.

2nd lowest April to-date average.

Lowest value for the date.

27 days this year (29.35% year-to-date) have recorded the lowest daily extent.

20 days (21.74%) have recorded the second lowest.

19 days (20.65%) have recorded the third lowest.

66 days (71.74%) in total have been among the three lowest on record.

CT Area:

12,992,694 km2 (02 April [Day 0.2493])

Down 281,861 km2 (2.12%) from 2015 maximum-to-date of 13,274,555 km2 on 17 February [Day 0.1288].

10,758,684 km2 above record minimum area of 2,234,010 km2 (14 September 2012).

Up 2,109 km2 from previous day.

Down 23,426 km2 over past seven days (daily average: -3,347 km2).

Up 2,548 km2 for the month of April (daily average: 1,274 km2).

357,645 km2 below 2000s average for this date.

309,521 km2 below 2010s average for this date.

78,188 km2 below 2014 value for this date.

558,293 km2 below 2012 value for this date.

3rd lowest April to-date average.

3rd lowest value for the date.

7 days this year (7.61% year-to-date) have recorded the lowest daily area.

8 days (8.7%) have recorded the second lowest.

8 days (8.7%) have recorded the third lowest.

23 days in total (25%) have been among the lowest three on record.

[viddaloo]

Down 54,426 km2 for the month of April (daily average: -27,213 km2).

And with that, we're in the Top 5 for April melts already, at #5. I'm guessing #1 by the end of month.

[Wipneus]

With the latest NSIDC's sea ice concentration , I expect the following changes of  CT-area:

Sat       12.981949
Sun -26.1 12.955855
Mon -109.5 12.846376

[OldLeatherneck]

Does anyone know why JAXA hasn't updated the Extent values since April 2nd??

[seaicesailor]

They are upgrading the system, in AMSR2 thread there was more info posted days ago

[Jim Pettit]

IJIS Extent:

13,409,765 km2 (07 April)

Down 532,295 km2 (3.82%) from 2015 maximum-to-date of 13,942,060 km2 on 15 February.

10,232,310 km2 above record minimum extent of 3,177,455 km2 (16 September 2012).

Down 36,123 km2 from previous day.

Down 255,546 km2 over past seven days (daily average: -36,507 km2).

Down 255,546 km2 for the month of April (daily average: -36,507 km2).

650,040 km2 below 2000s average for this date.

519,670 km2 below 2010s average for this date.

424,108 km2 below 2014 value for this date.

803,395 km2 below 2012 value for this date.

Lowest April to-date average.

Lowest value for the date.

32 days this year (32.99% year-to-date) have recorded the lowest daily extent.

20 days (20.62%) have recorded the second lowest.

19 days (19.59%) have recorded the third lowest.

71 days (73.2%) in total have been among the three lowest on record.

CT Area:

12,806,602 km2 (07 April [Day 0.2631])

Down 467,954 km2 (3.53%) from 2015 maximum-to-date of 13,274,555 km2 on 17 February [Day 0.1288].

10,572,592 km2 above record minimum area of 2,234,010 km2 (14 September 2012).

Up 9,091 km2 from previous day.

Down 183,544 km2 over past seven days (daily average: -26,221 km2).

Down 183,544 km2 for the month of April (daily average: -26,221 km2).

434,604 km2 below 2000s average for this date.

312,872 km2 below 2010s average for this date.

235,239 km2 below 2014 value for this date.

430,447 km2 below 2012 value for this date.

2nd lowest April to-date average.

2nd lowest value for the date.

7 days this year (7.22% year-to-date) have recorded the lowest daily area.

11 days (11.34%) have recorded the second lowest.

8 days (8.25%) have recorded the third lowest.

26 days in total (26.8%) have been among the lowest three on record.

[BornFromTheVoid]

Update for the week to April 4th

The current 5 day mean is on 14,259,400km2 while the 1 day extent is at 14,156,000km2.
The daily anomaly (compared to 81-10) is at -908,920km2, an increase from -907,130km2 last week. The anomaly compared to the 07, 11 and 12 average is at -349,600km2, an increase from -239,070km2 last week. We're currently 3rd lowest on record, the same as last week.



The average daily change over the last 7 days was -23.1k/day, compared to the long term average of -22.9k/day, and the 07, 11 and 12 average of -7.3k/day.
The average long term change over the next week is -35.2k/day, with the 07, 11, and 12 average being -33.6k/day.





The loss so far this April is the 18th largest on record. To achieve the largest recorded monthly loss, at least -61.4k/day is required, while the smallest loss requires less than -23.2k/day and an average requires a loss of -39.9k/day.



The change this March was the 12th least negative on record, while the average monthly extent was the lowest on record.

[crandles]

NSIDC 13.999 on 7th April. Previous earliest for below 14million km^2 was 9th April 2006

[Jim Pettit]

IJIS Extent:

13,446,594 km2 (11 April)

Down 495,466 km2 (3.55%) from 2015 maximum-to-date of 13,942,060 km2 on 15 February.

10,269,139 km2 above record minimum extent of 3,177,455 km2 (16 September 2012).

Up 14,264 km2 from previous day.

Down 57,666 km2 over past seven days (daily average: -8,238 km2).

Down 218,717 km2 for the month of April (daily average: -19,883 km2).

444,533 km2 below 2000s average for this date.

387,300 km2 below 2010s average for this date.

182,088 km2 below 2014 value for this date.

589,612 km2 below 2012 value for this date.

2nd lowest April to-date average.

3rd lowest value for the date.

32 days this year (31.68% year-to-date) have recorded the lowest daily extent.

23 days (22.77%) have recorded the second lowest.

20 days (19.8%) have recorded the third lowest.

75 days (74.26%) in total have been among the three lowest on record.

CT Area:

12,618,747 km2 (10 April [Day 0.2712])

Down 655,808 km2 (4.94%) from 2015 maximum-to-date of 13,274,555 km2 on 17 February [Day 0.1288].

10,384,737 km2 above record minimum area of 2,234,010 km2 (14 September 2012).

Down 50,067 km2 from previous day.

Down 363,202 km2 over past seven days (daily average: -51,886 km2).

Down 371,399 km2 for the month of April (daily average: -37,140 km2).

485,154 km2 below 2000s average for this date.

435,998 km2 below 2010s average for this date.

481,592 km2 below 2014 value for this date.

525,013 km2 below 2012 value for this date.

2nd lowest April to-date average.

2nd lowest value for the date.

7 days this year (70% year-to-date) have recorded the lowest daily area.

14 days (14%) have recorded the second lowest.

8 days (8%) have recorded the third lowest.

29 days in total (29%) have been among the lowest three on record.

[BornFromTheVoid]

Update for the week to April 12th

The current 5 day mean is on 14,062,200km2 while the 1 day extent is at 14,158,000km2.
The daily anomaly (compared to 81-10) is at -859,810km2, a decrease from -908,920km2 last week. The anomaly compared to the 07, 11 and 12 average is at -311,870km2, a decrease from -349,600km2 last week. We're currently 3rd lowest on record, the same as last week.



The average daily change over the last 7 days was -28.7k/day, compared to the long term average of -35.2k/day, and the 07, 11 and 12 average of -33.6k/day.
The average long term change over the next week is -40.0k/day, with the 07, 11, and 12 average being -24.5k/day.



The change so far this April was the 19th least negative on record. To achieve the largest monthly drop a daily loss of at least -48.3k/day is required, while the smallest drop requires less than 14.0k/day and an average drop requires 29.0k/day.

[Jim Pettit]

IJIS Extent:

13,355,159 km2 (15 April)

Down 586,901 km2 (4.21%) from 2015 maximum-to-date of 13,942,060 km2 on 15 February.

10,177,704 km2 above record minimum extent of 3,177,455 km2 (16 September 2012).

Down 47,165 km2 from previous day.

Down 31,871 km2 over past seven days (daily average: -4,553 km2).

Down 310,152 km2 for the month of April (daily average: -20,677 km2).

365,525 km2 below 2000s average for this date.

336,560 km2 below 2010s average for this date.

72,424 km2 below 2014 value for this date.

695,371 km2 below 2012 value for this date.

2nd lowest April to-date average.

4th lowest value for the date.

32 days this year (30.48% year-to-date) have recorded the lowest daily extent.

23 days (21.9%) have recorded the second lowest.

20 days (19.05%) have recorded the third lowest.

75 days (71.43%) in total have been among the three lowest on record.

[Wipneus]

CT has not updated for a while. From the NSIDC ice concentration data, I expect the following updates if/when it does:

Sun       12.653315
Mon +43.7 12.697045
Tue +62.2 12.759217
Wed -92.9 12.666365
Thu -35.7 12.630620
Fri -9.4 12.621183
Sat -70.2 12.550960

[BornFromTheVoid]

Update for the week to April 18th

The current 5 day mean is on 14,019,200km2 while the 1 day extent is at 13,972,000km2.
The daily anomaly (compared to 81-10) is at -623,070km2, a decrease from -859,810km2 last week. The anomaly compared to the 07, 11 and 12 average is at -183,400km2, a decrease from -311,870km2 last week. We're currently 5th lowest on record, down from 3rd lowest last week.



The average daily change over the last 7 days was -6.3k/day, compared to the long term average of -40.0k/day, and the 07, 11 and 12 average of -24.5k/day.
The average long term change over the next week is -36.3k/day, with the 07, 11, and 12 average being -27.4k/day.



The loss so far this April is the 4th smallest on record. To achieve the largest monthly drop, a daily loss of at least 113.1k/day is required, while the smallest drop requires less than 30.3k/day and an average drop requires 66.5k/day.

[Stephen]

CT has not updated for a while. ......

Have they explained why?  Maybe they have hangovers from an extended spring break?

[Phil.]

CT has not updated for a while. ......

Have they explained why?  Maybe they have hangovers from an extended spring break?

Noticed that they're showing a different less detailed graph and no numerical values today.

[Wipneus]

I can not say that I expect anything from Cryosphere Today anymore, but this is what would/could be had:

Sun       12.653315
Mon +43.7 12.697045
Tue +62.2 12.759217
Wed -92.9 12.666365
Thu -35.7 12.630620
Fri -9.4 12.621183
Sat -64.4 12.556754
Sun -22.0 12.534755
Mon +37.9 12.572678
Tue -45.7 12.526964
Wed -74.4 12.452570
Thu -39.8 12.412783
Fri -42.0 12.370804
Sat -40.1 12.330725
Sun -116.7 12.214050
Mon -187.1 12.026918

[Shared Humanity]

Has there been any explanation as to why they have stopped reporting?

[Nightvid Cole]

CT has not updated for a while. ......

Have they explained why?  Maybe they have hangovers from an extended spring break?

After this long and still no reporting, must be a coma, not just a hangover...

[Jim Pettit]

IJIS Extent:

12,998,194 km2 (25 April)

Down 943,866 km2 (6.77%) from 2015 maximum of 13,942,060 km2 on 15 February.

9,820,739 km2 above record minimum extent of 3,177,455 km2 (16 September 2012).

Down 112,000 km2 from previous day.

Down 345,422 km2 over past seven days (daily average: -49,346 km2).

Down 667,117 km2 for the month of April (daily average: -26,685 km2).

365,135 km2 below 2000s average for this date.

268,189 km2 below 2010s average for this date.

38,237 km2 below 2014 value for this date.

562,506 km2 below 2012 value for this date.

3rd lowest April to-date average.

3rd lowest value for the date.

32 days this year (27.83% year-to-date) have recorded the lowest daily extent.

23 days (20%) have recorded the second lowest.

21 days (18.26%) have recorded the third lowest.

76 days (66.09%) in total have been among the three lowest on record.

CT Area:

NOTE: due to the prolonged absence of official CT sea ice area data, I've instead used Wipneus' calculated area numbers for the period from 12 April through 25 April. The official numbers will be inserted if/when available. In the meantime, thanks, Wipneus!

12,214,050 km2 (25 April [Day 0.3124])

Down 1,060,505 km2 (7.99%) from 2015 maximum-to-date of 13,274,555 km2 on 17 February [Day 0.1288].

9,980,041 km2 above record minimum area of 2,234,010 km2 (14 September 2012).

Down 116,675 km2 from previous day.

Down 320,705 km2 over past seven days (daily average: -45,815 km2).

Down 776,096 km2 for the month of April (daily average: -31,044 km2).

303,019 km2 below 2000s average for this date.

234,343 km2 below 2010s average for this date.

14,052 km2 above 2014 value for this date.

662,992 km2 below 2012 value for this date.

3rd lowest April to-date average.

3rd lowest value for the date.

7 days this year (6.09% year-to-date) have recorded the lowest daily area.

14 days (12.17%) have recorded the second lowest.

13 days (11.3%) have recorded the third lowest.

34 days in total (29.57%) have been among the lowest three on record.

[BornFromTheVoid]

Update for the week to April 25th

The current 5 day mean is on 13,875,400km2 while the 1 day extent is at 13,695,000km2.
The daily anomaly (compared to 81-10) is at -512,730km2, a decrease from -623,070km2 last week. The anomaly compared to the 07, 11 and 12 average is at -135,400km2, a decrease from -183,400km2 last week. We're currently 6th lowest on record, down from 5th lowest last week.



The average daily change over the last 7 days was -20.5k/day, compared to the long term average of -36.3k/day, and the 07, 11 and 12 average of -27.4k/day.
The average long term change over the next week is -54.8k/day, with the 07, 11, and 12 average being -60.6k/day.



The loss so far this April is the 2nd smallest on record. To achieve the largest monthly drop, a daily loss of at least 242.6k/day is required, while the smallest drop requires less than 44.0k/day and an average drop requires 130.9k/day.

[James Lovejoy]

I emailed CT asking about the 'pause' in reporting.

The reply stated it was caused by computer problems, and they hope to have them resolved this week.

Maybe we'll have new data from them this week.   

[Jim Pettit]

IJIS Extent:

12,911,507 km2 (26 April)

Down 1,030,553 km2 (7.39%) from 2015 maximum of 13,942,060 km2 on 15 February.

9,734,052 km2 above record minimum extent of 3,177,455 km2 (16 September 2012).

Down 86,687 km2 from previous day.

Down 413,913 km2 over past seven days (daily average: -59,130 km2).

Down 753,804 km2 for the month of April (daily average: -28,992 km2).

403,551 km2 below 2000s average for this date.

271,687 km2 below 2010s average for this date.

67,371 km2 below 2014 value for this date.

525,399 km2 below 2012 value for this date.

3rd lowest April to-date average.

2nd lowest value for the date.

32 days this year (27.59% year-to-date) have recorded the lowest daily extent.

24 days (20.69%) have recorded the second lowest.

21 days (18.1%) have recorded the third lowest.

77 days (66.38%) in total have been among the three lowest on record.

CT Area:

NOTE: due to the prolonged absence of official CT sea ice area data, I've instead used Wipneus' calculated area numbers for the period from 12 April through 26 April. The official numbers will be inserted if/when available. In the meantime: thanks, Wipneus!

12,026,918 km2 (26 April [Day 0.3151])

Down 1,247,637 km2 (9.4%) from 2015 maximum of 13,274,555 km2 on 17 February [Day 0.1288].

9,792,909 km2 above record minimum area of 2,234,010 km2 (14 September 2012).

Down 187,132 km2 from previous day.

Down 545,760 km2 over past seven days (daily average: -77,966 km2).

Down 963,228 km2 for the month of April (daily average: -37,047 km2).

446,038 km2 below 2000s average for this date.

349,129 km2 below 2010s average for this date.

252,986 km2 below 2014 value for this date.

839,347 km2 below 2012 value for this date.

Sixth lowest April to-date average.

2nd lowest value for the date.

7 days this year (6.03% year-to-date) have recorded the lowest daily area.

15 days (12.93%) have recorded the second lowest.

13 days (11.21%) have recorded the third lowest.

35 days in total (30.17%) have been among the lowest three on record.

[jdallen]

Update for the week to April 25th...

The loss so far this April is the 2nd smallest on record. To achieve the largest monthly drop, a daily loss of at least 242.6k/day is required, while the smallest drop requires less than 44.0k/day and an average drop requires 130.9k/day.

Thank you as usual, BFtV.

I'd posit the low numbers are a direct outcome of ice missing from areas which previously, typically, would start melting out at this point in the season.

Hard to imagine another explanation, considering the anomalous persistent heat we have seen going back all the way to the end of last year's melt season.

[LRC1962]

I'd posit the low numbers are a direct outcome of ice missing from areas which previously, typically, would start melting out at this point in the season.

Hard to imagine another explanation, considering the anomalous persistent heat we have seen going back all the way to the end of last year's melt season.

Could a possibility be that the anomalous heat over winter not affect the extent, but the thickness or rottenness of the ice? If that were the case then it would be still too cold for true melt off to occur. But latter in the season once the temps get high enough, then we could get a big melt off as the thickness/rottenness of the ice comes into effect.

[Buddy]

BINGO....

[Yuha]

I'd posit the low numbers are a direct outcome of ice missing from areas which previously, typically, would start melting out at this point in the season.

You are right.

Looking at Wipneus' extend graphs:
https://sites.google.com/site/arcticseaicegraphs/regional
it's clear that April losses usually come mostly from Okhotsk, Bering and Barents but this April started with exceptionally low extends in those regions. The ice that would normally melt in April was already missing in the beginning of April.

Still, in the beginning of April there was a lot of ice that could have melted during April, particularly in Okhotsk, Bering and Baffin/Newfoundland regions, but the temperatures in those areas have not been conductive to melting until the last few days. That's where the recent big drops have happened.

[Neven]

I'd posit the low numbers are a direct outcome of ice missing from areas which previously, typically, would start melting out at this point in the season.

You are right.

Looking at Wipneus' extend graphs:
https://sites.google.com/site/arcticseaicegraphs/regional
it's clear that April losses usually come mostly from Okhotsk, Bering and Barents but this April started with exceptionally low extends in those regions. The ice that would normally melt in April was already missing in the beginning of April.

Still, in the beginning of April there was a lot of ice that could have melted during April, particularly in Okhotsk, Bering and Baffin/Newfoundland regions, but the temperatures in those areas have not been conductive to melting until the last few days. That's where the recent big drops have happened.

Yes, the Bering has dropped of a small cliff, and the winds having blown the ice so far out, it's probably going to keep up a couple of days. And in the coming week Hudson Bay is going to experience above freezing temps. At the same time almost all of the Arctic will be enveloped by high pressure, meaning insolation, but also little transport and temps staying below zero.

In this respect it will be interesting to see what the DMI 80N temp graph does. It's still positive right now, but going down again, and we're one week away when the trend line went negative in 2013 and 2014 and stayed that way for practically the entire melting season, but more importantly: during that crucial first phase of the melting season: Melt Pond May and Jolly June (I have to think of a better one for June  ).

[Sebastian]

(I have to think of a better one for June  ).

Junction June? When we start to really see where the season is going.

[seaicesailor]

I'd posit the low numbers are a direct outcome of ice missing from areas which previously, typically, would start melting out at this point in the season.

You are right.

Looking at Wipneus' extend graphs:
https://sites.google.com/site/arcticseaicegraphs/regional
it's clear that April losses usually come mostly from Okhotsk, Bering and Barents but this April started with exceptionally low extends in those regions. The ice that would normally melt in April was already missing in the beginning of April.

Still, in the beginning of April there was a lot of ice that could have melted during April, particularly in Okhotsk, Bering and Baffin/Newfoundland regions, but the temperatures in those areas have not been conductive to melting until the last few days. That's where the recent big drops have happened.

Yes, the Bering has dropped of a small cliff, and the winds having blown the ice so far out, it's probably going to keep up a couple of days. And in the coming week Hudson Bay is going to experience above freezing temps. At the same time almost all of the Arctic will be enveloped by high pressure, meaning insolation, but also little transport and temps staying below zero.

In this respect it will be interesting to see what the DMI 80N temp graph does. It's still positive right now, but going down again, and we're one week away when the trend line went negative in 2013 and 2014 and stayed that way for practically the entire melting season, but more importantly: during that crucial first phase of the melting season: Melt Pond May and Jolly June (I have to think of a better one for June  ).

The DMI 80+ temp anomaly did become negative around day 120 for 2012, 2007, and 2011 as well, and stayed so through May and June (except some days for 2011).

So I don't think that, by itself, it is such a relevant indicator. I have no real physical argument to say so,  just what the data of these other years say.

[seaicesailor]

I'd posit the low numbers are a direct outcome of ice missing from areas which previously, typically, would start melting out at this point in the season.

Hard to imagine another explanation, considering the anomalous persistent heat we have seen going back all the way to the end of last year's melt season.

Could a possibility be that the anomalous heat over winter not affect the extent, but the thickness or rottenness of the ice? If that were the case then it would be still too cold for true melt off to occur. But latter in the season once the temps get high enough, then we could get a big melt off as the thickness/rottenness of the ice comes into effect.

Chances are the ice temperature right now is higher of what would have been with lower winter temps, since this is way enthalpy anomaly during winter is retained; thickness would be lower too. However one cannot say for sure without knowledge of how much heat radiated back to space. I dont think it would affect ice or snow health or rottenness

[Neven]

(I have to think of a better one for June  ).

Junction June? When we start to really see where the season is going.

That's a good one. I'll have to remember that. 

The DMI 80+ temp anomaly did become negative around day 120 for 2012, 2007, and 2011 as well, and stayed so through May and June (except some days for 2011).

So I don't think that, by itself, it is such a relevant indicator. I have no real physical argument to say so,  just what the data of these other years say.

You're absolutely right. Somehow I didn't look further back past 2013, or if I did, didn't pay enough attention. I often think people make too much out of the DMI 80N temp graph, and here I go doing it myself. Must be them spectacular spikes.

[jai mitchell]

we're one week away when the trend line went negative in 2013 and 2014 and stayed that way for practically the entire melting season, but more importantly: during that crucial first phase of the melting season: Melt Pond May and Jolly June (I have to think of a better one for June  ).

2009-2011 also had similar dips, 2012 and 2007 had dips below the trend at earlier dates and then recovered just slightly above the trend just as it was crossing the average 0C line.

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

[Neven]

2009-2011 also had similar dips, 2012 and 2007 had dips below the trend at earlier dates and then recovered just slightly above the trend just as it was crossing the average 0C line.

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

There is indeed a slight difference in that 2013 and 2014 stay firmly below average, where other years from Junction June onwards hover around it.

But anyway, this should be in the melting season topic. I wasn't paying attention.

[seaicesailor]

2009-2011 also had similar dips, 2012 and 2007 had dips below the trend at earlier dates and then recovered just slightly above the trend just as it was crossing the average 0C line.

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

There is indeed a slight difference in that 2013 and 2014 stay firmly below average, where other years from Junction June onwards hover around it.

But anyway, this should be in the melting season topic. I wasn't paying attention.

Hi Neven, I posted a comment on this in the Melting season thread to stay on topic.

[Jim Pettit]

IJIS Extent:

12,707,016 km2 (30 April)

Down 1,235,044 km2 (8.86%) from 2015 maximum of 13,942,060 km2 on 15 February.

9,529,561 km2 above record minimum extent of 3,177,455 km2 (16 September 2012).

Down 23,313 km2 from previous day.

Down 505,384 km2 over past seven days (daily average: -72,198 km2).

Down 958,295 km2 for the month of April (daily average: -31,943 km2).

439,986 km2 below 2000s average for this date.

278,716 km2 below 2010s average for this date.

186,699 km2 below 2014 value for this date.

451,695 km2 below 2012 value for this date.

3rd lowest April average.

2nd lowest value for the date.

33 days this year (27.5% year-to-date) have recorded the lowest daily extent.

27 days (22.5%) have recorded the second lowest.

21 days (17.5%) have recorded the third lowest.

81 days (67.5%) in total have been among the three lowest on record.

[Wipneus]

While waiting for CT to restore its data stream, here is my approximation of it, with a solid century this Monday:


Sun       12.653315
Mon +43.7 12.697045
Tue +62.2 12.759217
Wed -92.9 12.666365
Thu -35.7 12.630620
Fri -9.4 12.621183
Sat -64.4 12.556754
Sun -22.0 12.534755
Mon +37.9 12.572678
Tue -45.7 12.526964
Wed -74.4 12.452570
Thu -39.8 12.412783
Fri -42.0 12.370804
Sat -40.1 12.330725
Sun -116.7 12.214050
Mon -187.4 12.026666
Tue -26.7 11.999984
Wed -14.9 11.985108
Thu +8.4 11.993483
Fri +13.9 12.007337
Sat -1.2 12.006169
Sun -7.0 11.999147
Mon -146.1 11.853065

[crandles]

Mon .3342
2006 11.5360041
2008 11.7168293
1990 11.7926712
2007 11.8036528
2013 11.8037691
2015 11.853065
2014 11.8846378
2004 11.9914856
2010 11.9924707

so 6th lowest for date

[BornFromTheVoid]

Update for the week to May 3rd

The current 5 day mean is on 13,317,400km2 while the 1 day extent is at 13,111,000km2.
The daily anomaly (compared to 81-10) is at -687,360km2, an increase from -512,730km2 last week. The anomaly compared to the 07, 11 and 12 average is at -269,070km2, an increase from -135,400km2 last week. We're currently 3rd lowest on record, down from 6th lowest last week.



The average daily change over the last 7 days was -79.7k/day, compared to the long term average of -54.8k/day, and the 07, 11 and 12 average of -60.6k/day.
The average long term change over the next week is -50.7k/day, with the 07, 11, and 12 average being -49.4k/day.



The loss so far this May is the 4th largest on record. To achieve the largest monthly drop, a daily loss of at least 67.0k/day is required, while the smallest drop requires less than 20.3k/day and an average drop requires 43.5k/day.



The extent loss this April was the 8th smallest on record, while the average monthly extent was the 3rd lowest on record.

[Jim Pettit]

IJIS Extent:

12,523,337 km2 (05 May)

Down 1,418,723 km2 (10.18%) from 2015 maximum of 13,942,060 km2 on 15 February.

9,345,882 km2 above record minimum extent of 3,177,455 km2 (16 September 2012).

Down 65,661 km2 from previous day.

Down 292,433 km2 over past seven days (daily average: -41,776 km2).

Down 183,679 km2 for the month of May (daily average: -36,736 km2).

387,229 km2 below 2000s average for this date.

196,172 km2 below 2010s average for this date.

91,075 km2 below 2014 value for this date.

306,069 km2 below 2012 value for this date.

3rd lowest May to-date average.

3rd lowest value for the date.

33 days this year (26.4% year-to-date) have recorded the lowest daily extent.

29 days (23.2%) have recorded the second lowest.

24 days (19.2%) have recorded the third lowest.

86 days (68.8%) in total have been among the three lowest on record.

NOTE: Cryosphere Today updated their file this morning, so all SIA data here are now official, including those data from Day 0.2767 forward.

CT Area:

11,796,725 km2 (05 May [Day 0.3397])

Down 1,477,830 km2 (11.13%) from 2015 maximum of 13,274,555 km2 on 17 February [Day 0.1288].

9,562,716 km2 above record minimum area of 2,234,010 km2 (14 September 2012).

Down 36,581 km2 from previous day.

Down 188,061 km2 over past seven days (daily average: -26,866 km2).

Down 209,744 km2 for the month of May (daily average: -41,949 km2).

186,942 km2 below 2000s average for this date.

53,701 km2 above 2010s average for this date.

2,427 km2 above 2014 value for this date.

153,401 km2 below 2012 value for this date.

7th lowest May to-date average.

8th lowest value for the date.

7 days this year (5.6% year-to-date) have recorded the lowest daily area.

15 days (12%) have recorded the second lowest.

15 days (12%) have recorded the third lowest.

37 days in total (29.6%) have been among the lowest three on record.

[Wipneus]

CT is back again!

My last prediction, calculated fro NSIDC sea ice concentration data, was:


Wed -36.6 11.797073


Today CT reported:

-36k6 11.796725

That is 0.3k off (about half a "pixel" at 100%)

For Friday another century is coming:


Wed       11.796725
Thu -34.5 11.762206
Fri -169.4 11.592817

[Tor Bejnar]

With no 'truth testing', so to speak, for a month (was it that long?), that tiny discrepancy is not only cool, but outstandingly frosty!  (Cool and frosty being good for Arctic ice and therefore good for children.)

[oren]

CT is back again!

My last prediction, calculated fro NSIDC sea ice concentration data, was:


Wed -36.6 11.797073


Today CT reported:

-36k6 11.796725

That is 0.3k off (about half a "pixel" at 100%)

For Friday another century is coming:


Wed       11.796725
Thu -34.5 11.762206
Fri -169.4 11.592817

To say that your precision is impressive would be an understatement

[Jim Pettit]

IJIS Extent:

12,390,148 km2 (07 May)

Down 1,551,912 km2 (11.13%) from 2015 maximum of 13,942,060 km2 on 15 February.

9,212,693 km2 above record minimum extent of 3,177,455 km2 (16 September 2012).

Down 34,962 km2 from previous day.

Down 316,868 km2 over past seven days (daily average: -45,267 km2).

Down 316,868 km2 for the month of May (daily average: -45,267 km2).

418,541 km2 below 2000s average for this date.

240,662 km2 below 2010s average for this date.

134,713 km2 below 2014 value for this date.

421,854 km2 below 2012 value for this date.

3rd lowest May to-date average.

3rd lowest value for the date.

33 days this year (25.98% year-to-date) have recorded the lowest daily extent.

29 days (22.83%) have recorded the second lowest.

26 days (20.47%) have recorded the third lowest.

88 days (69.29%) in total have been among the three lowest on record.

CT Area:

11,593,455 km2 (07 May [Day 0.3452])

Down 1,681,100 km2 (12.66%) from 2015 maximum of 13,274,555 km2 on 17 February [Day 0.1288].

9,359,446 km2 above record minimum area of 2,234,010 km2 (14 September 2012).

Down 169,345 km2 from previous day.

Down 413,014 km2 over past seven days (daily average: -59,002 km2).

Down 413,014 km2 for the month of May (daily average: -59,002 km2).

326,905 km2 below 2000s average for this date.

66,950 km2 below 2010s average for this date.

150,433 km2 below 2014 value for this date.

271,646 km2 below 2012 value for this date.

6th lowest May to-date average.

3rd lowest value for the date.

7 days this year (5.51% year-to-date) have recorded the lowest daily area.

15 days (11.81%) have recorded the second lowest.

16 days (12.6%) have recorded the third lowest.

38 days in total (29.92%) have been among the lowest three on record.

[Buddy]

421,854 km2 below 2012 value for this date.

THAT....will continue to be the interesting statistic to track as we head towards a new record low come September.

The only thing in my mind.....is how much lower than 2012 will it be.

[andy_t_roo]

CT is back again!

My last prediction, calculated fro NSIDC sea ice concentration data, was:


Wed -36.6 11.797073


Today CT reported:

-36k6 11.796725

That is 0.3k off (about half a "pixel" at 100%)

Do you think that this indicates that numbers displayed to that precision present false certainty?
Perhaps the last 2 didgets could be removed, leaving the last significant figure at 0.1k, or less than 1/4 a pixel. Given the resolution and noise of the data, this difference could even be caused by floating point error accumulations on a even a perfect match of the actual underlying maths. I don't believe these last 2 figures tell us anything