Author Topic: 2014 sea ice area and extent data (Read 651513 times)

Jim Pettit · « **Reply #950 on:** August 26, 2014, 01:23:17 PM »

IJIS Extent:

5,304,377 km2 (25 August)

Down 9,144,039 km2 (63.29%) from 2014 maximum of 14,448,416 km2 on 20 March.

2,126,922 km2 above record minimum extent of 3,177,455 km2 (16 September 2012).

Down 34,281 km2 from previous day.

Down 370,484 km2 over past seven days (daily average: -52,926 km2).

Down 1,458,752 km2 for the month of August (daily average: -58,350 km2).

563,474 km2 below 2000s average for this date.

401,546 km2 above 2010s average for this date.

65,238 km2 below 2013 value for this date.

1,568,067 km2 above 2012 value for this date.

Fourth lowest August to-date average.

Fifth lowest value for the date.

11 days this year (4.64% year-to-date) have recorded the lowest daily extent.

14 days (5.91%) have recorded the second lowest.

56 days (23.63%) have recorded the third lowest.

81 days (34.18%) in total have been among the three lowest on record.

CT Area:

4,023,862 km2 (25 August [Day 0.6466])

Down 9,463,475 km2 (70.17%) from 2014 maximum of 13,487,337 km2 on 22 March [Day 0.2192].

1,789,853 km2 above record minimum area of 2,234,010 km2 (14 September 2012).

Down 44,076 km2 from previous day.

Down 507,979 km2 over past seven days (daily average: -72,568 km2).

Down 1,120,034 km2 for the month of August (daily average: -44,801 km2).

171,073 km2 below 2000s average for this date.

569,773 km2 above 2010s average for this date.

110,507 km2 above 2013 value for this date.

1,296,787 km2 above 2012 value for this date.

Eighth lowest August to-date average.

Eighth lowest value for the date.

12 days this year (5.06% year-to-date) have recorded the lowest daily area.

21 days (8.86%) have recorded the second lowest.

17 days (7.17%) have recorded the third lowest.

50 days in total (21.1%) have been among the lowest three on record.

SIA is now lower than the minima recorded in every year prior to 2006.

If the melt season ended today, 2014 would go down as 9th lowest on record.

Wipneus · « **Reply #951 on:** August 26, 2014, 04:26:13 PM »

From area calculated from NSIDC sea ice concentration I expect the following changes of CT-area:

Wed: -76k (no change)
Thu: +18k

The regional breakdown is as follows:

Regional Arctic Sea Ice Extent and Area calculated from NSIDC NASA Team concentration data Date: 2014-08-25 12:00 Values in 1000 km^2 Anomalies are from the 1981-2010 mean values Extent (value, one day change, anomaly): Arctic Basin East Siberian Sea Laptev Sea 4000.2 -10.5 -312.5 332.7 -12.2 -166.3 8.9 -6.3 -286.3 Kara Sea Barents Sea Greenland Sea 156.9 +19.3 -112.4 139.4 +11.7 +85.4 167.5 -15.7 -76.1 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 27.5 +1.7 -46.2 0.0 +0.0 +0.0 69.8 +30.9 -4.4 Canadian Archipelago Beaufort Sea Chukchi Sea 522.2 -23.8 +72.0 177.7 -2.5 -113.4 10.2 -3.8 -151.8 Bering Sea Sea of Okhotsk Lakes 0.0 +0.0 +0.0 0.0 +0.0 +0.0 146.4 +1.4 +14.3 Other regions Total (ex. lakes) 0.0 +0.0 +0.0 5613.1 -11.3 -1112.0 Area (value, one day change, anomaly): Arctic Basin East Siberian Sea Laptev Sea 3211.1 +19.8 -338.9 133.0 -4.9 -176.5 4.4 -1.6 -173.1 Kara Sea Barents Sea Greenland Sea 62.2 +7.6 -87.3 65.1 +1.7 +43.2 77.1 -8.4 -35.5 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 11.9 -0.2 -21.5 0.0 +0.0 +0.0 29.1 +16.5 +4.1 Canadian Archipelago Beaufort Sea Chukchi Sea 302.9 -11.1 +38.5 91.1 -7.1 -73.4 2.7 -0.9 -80.8 Bering Sea Sea of Okhotsk Lakes 0.0 +0.0 +0.0 0.0 +0.0 +0.0 85.8 +3.9 +28.4 Other regions Total (ex. lakes) 0.0 +0.0 +0.0 3990.5 +11.5 -901.2

crandles · « **Reply #952 on:** August 26, 2014, 04:57:37 PM »

CT area with Wipneus' updates:
4.024 - 0.076 =3.948 + 0.018 = 3.966

4.024 / 3.948 / 3.966 is 8th lowest year for area even if there is no further decline.

Next target is 3.554 so requires a further drop of 0.412.

compared with same day of year:
2012.6521 -2.3357551 2.5944920
2007.6521 -1.9366651 3.0380161
2011.6521 -1.8935559 3.0811253
2008.6521 -1.7312514 3.1989956
2010.6521 -1.4102585 3.5644226
2009.6521 -1.2165875 3.7580936
2013.6521 -1.1520052 3.8226759
2014_______________3.966
2005.6521 -0.7423565 4.2323246
2006.6521 -0.7128507 4.2618303
2002.6521 -0.6054909 4.3691902

Remains 8th lowest for day.
Up to 1372k above 2012.

Losses from day .6521 to minimum and where we end if losses from now on are the same
2005   0.141   3.825 (8th lowest)
2006   0.232   3.734 (8th lowest)
2007   0.119   3.847 (8th lowest)
2008   0.195   3.771 (8th lowest)
2009   0.333   3.633 (8th lowest)
2010   0.492   3.474 (7th lowest)
2011   0.176   3.790 (8th lowest)
2012   0.360   3.606 (8th lowest)
2013   0.268   3.698 (8th lowest)

07+Average___   0.278   3.688 (8th lowest)
07+Average+3sd   0.661   3.305 (6th lowest)
07+Average+2sd   0.533   3.433 (7th lowest)
07+Average+sd_   0.406   3.560 (8th lowest)
07+Average-sd_   0.150   3.816 (8th lowest)
07+Average-2sd   0.022   3.944 (8th lowest)
07+Average-3sd   -0.106   4.072 (projected 3.948 8th lowest)

Further CT losses for 2007 onwards range is down to 0.1 to 0.5. Typical reductions like years 2007 onwards using 1sd range results in 8th lowest area, using 2sd range leads to 7th to 8th lowest area, and using 3sd deviation range leads to 6th to 8th lowest area.

Jim Pettit · « **Reply #953 on:** August 27, 2014, 01:07:16 PM »

IJIS Extent:

5,279,124 km2 (26 August)

Down 9,169,292 km2 (63.46%) from 2014 maximum of 14,448,416 km2 on 20 March.

2,101,669 km2 above record minimum extent of 3,177,455 km2 (16 September 2012).

Down 25,253 km2 from previous day.

Down 335,584 km2 over past seven days (daily average: -47,941 km2).

Down 1,484,005 km2 for the month of August (daily average: -57,077 km2).

555,636 km2 below 2000s average for this date.

420,628 km2 above 2010s average for this date.

47,491 km2 below 2013 value for this date.

1,597,517 km2 above 2012 value for this date.

Sixth lowest August to-date average.

Sixth lowest value for the date.

11 days this year (4.62% year-to-date) have recorded the lowest daily extent.

14 days (5.88%) have recorded the second lowest.

56 days (23.53%) have recorded the third lowest.

81 days (34.03%) in total have been among the three lowest on record.

CT Area:

3,944,846 km2 (26 August [Day 0.6493])

Down 9,542,491 km2 (70.75%) from 2014 maximum of 13,487,337 km2 on 22 March [Day 0.2192].

1,710,836 km2 above record minimum area of 2,234,010 km2 (14 September 2012).

Down 79,016 km2 from previous day.

Down 550,904 km2 over past seven days (daily average: -78,701 km2).

NOTE: Largest ever decrease for the week (Day 0.6329-0.6493, inclusive).

Down 1,199,050 km2 for the month of August (daily average: -46,117 km2).

185,536 km2 below 2000s average for this date.

530,460 km2 above 2010s average for this date.

87,989 km2 above 2013 value for this date.

1,301,684 km2 above 2012 value for this date.

Eighth lowest August to-date average.

Eighth lowest value for the date.

12 days this year (5.04% year-to-date) have recorded the lowest daily area.

21 days (8.82%) have recorded the second lowest.

17 days (7.14%) have recorded the third lowest.

50 days in total (21.01%) have been among the lowest three on record.

CT SIA is now lower than the minima recorded in every year up to and including 2006

Wipneus · « **Reply #954 on:** August 27, 2014, 05:06:25 PM »

From area calculated from NSIDC sea ice concentration I expect the following changes of CT-area:

Thu: +18k (not changed)
Fri: -16k

Area and extent drop mostly due to the ESS.

The regional breakdown is as follows:

Regional Arctic Sea Ice Extent and Area calculated from NSIDC NASA Team concentration data Date: 2014-08-26 12:00 Values in 1000 km^2 Anomalies are from the 1981-2010 mean values Extent (value, one day change, anomaly): Arctic Basin East Siberian Sea Laptev Sea 3995.0 -5.2 -312.5 318.1 -14.6 -174.4 11.5 +2.5 -278.1 Kara Sea Barents Sea Greenland Sea 160.1 +3.2 -104.0 143.3 +3.9 +90.1 167.6 +0.1 -73.0 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 34.8 +7.2 -37.5 0.0 +0.0 +0.0 42.1 -27.7 -28.9 Canadian Archipelago Beaufort Sea Chukchi Sea 531.4 +9.2 +85.7 186.0 +8.3 -102.6 11.5 +1.3 -147.9 Bering Sea Sea of Okhotsk Lakes 0.0 +0.0 +0.0 0.0 +0.0 +0.0 152.9 +6.6 +20.0 Other regions Total (ex. lakes) 0.0 +0.0 +0.0 5601.3 -11.8 -1083.0 Area (value, one day change, anomaly): Arctic Basin East Siberian Sea Laptev Sea 3212.3 +1.1 -322.9 116.0 -17.1 -190.0 4.8 +0.4 -169.1 Kara Sea Barents Sea Greenland Sea 63.0 +0.9 -83.6 67.8 +2.6 +46.1 79.9 +2.9 -31.4 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 15.6 +3.7 -17.4 0.0 +0.0 +0.0 14.1 -15.0 -9.9 Canadian Archipelago Beaufort Sea Chukchi Sea 301.7 -1.1 +39.7 98.2 +7.1 -65.8 3.0 +0.3 -79.2 Bering Sea Sea of Okhotsk Lakes 0.0 +0.0 +0.0 0.0 +0.0 +0.0 85.2 -0.6 +27.5 Other regions Total (ex. lakes) 0.0 +0.0 +0.0 3976.3 -14.2 -883.6

crandles · « **Reply #955 on:** August 27, 2014, 07:35:06 PM »

CT area with Wipneus' updates:
3.945 + 0.018 - 0.016 = 3.947

3.945 is 8th lowest year for area even if there is no further decline.

Next target is 3.554 so requires a further drop of 0.393

compared with same day of year:
2012.6548 -2.3283741 2.569563
2007.6548 -1.8244559 3.1057911
2011.6548 -1.8083068 3.1219401
2008.6548 -1.6765082 3.2214293
2010.6548 -1.4392825 3.4909644
2009.6548 -1.2190710 3.7111759
2013.6548 -1.1637510 3.7664959
2014_______________3.947
2005.6548 -0.7000868 4.2301602
2006.6548 -0.6311361 4.2991109
2002.6548 -0.6148669 4.3153801

Remains 8th lowest for day.
Up to 1377k above 2012.

Losses from day .6548 to minimum and where we end if losses from now on are the same
2005   0.138   3.809 (8th lowest)
2006   0.269   3.678 (8th lowest)
2007   0.186   3.761 (8th lowest)
2008   0.218   3.729 (8th lowest)
2009   0.287   3.660 (8th lowest)
2010   0.419   3.528 (7th lowest)
2011   0.217   3.730 (8th lowest)
2012   0.336   3.611 (8th lowest)
2013   0.212   3.735 (8th lowest)

07+Average___   0.268   3.679 (8th lowest)
07+Average+3sd   0.521   3.426 (7th lowest)
07+Average+2sd   0.437   3.510 (7th lowest)
07+Average+sd_   0.352   3.595 (8th lowest)
07+Average-sd_   0.183   3.764 (8th lowest)
07+Average-2sd   0.099   3.848 (8th lowest)
07+Average-3sd   0.015   3.932 (8th lowest)

Further CT losses for 2007 onwards range is down to 0.2 to 0.4. Typical reductions like years 2007 onwards using 1sd range results in 8th lowest area, using 2sd range leads to 7th to 8th lowest area, and using 3sd deviation range leads to 7th to 8th lowest area.

deep octopus · « **Reply #956 on:** August 27, 2014, 11:15:47 PM »

One-day NSIDC extent is now below the 2002 minimum, bringing to 27 the number of years whose minima 2014 has passed: 1979, 1980, 1981, 1982, 1983, 1984, 1985, 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, and 2006.

2014 has now clinched a spot in the nine (9) lowest years on record. 2014 is about 300,000 km² above the 2005 minimum, the next year to be surpassed.

Jim Pettit · « **Reply #957 on:** August 28, 2014, 01:11:17 PM »

IJIS Extent:

5,264,442 km2 (27 August)

Down 9,183,974 km2 (63.56%) from 2014 maximum of 14,448,416 km2 on 20 March.

2,086,987 km2 above record minimum extent of 3,177,455 km2 (16 September 2012).

Down 14,682 km2 from previous day. (NOTE: smallest one-day decrease since 08 June)

Down 287,514 km2 over past seven days (daily average: -41,073 km2).

Down 1,498,687 km2 for the month of August (daily average: -55,507 km2).

535,322 km2 below 2000s average for this date.

446,498 km2 above 2010s average for this date.

1,865 km2 above 2013 value for this date.

1,619,256 km2 above 2012 value for this date.

7th August to-date average.

7th lowest value for the date.

11 days this year (4.6% year-to-date) have recorded the lowest daily extent.

14 days (5.86%) have recorded the second lowest.

56 days (23.43%) have recorded the third lowest.

81 days (33.89%) in total have been among the three lowest on record.

CT Area:

3,966,561 km2 (27 August [Day 0.6521])

Down 9,520,777 km2 (70.59%) from 2014 maximum of 13,487,337 km2 on 22 March [Day 0.2192].

1,732,551 km2 above record minimum area of 2,234,010 km2 (14 September 2012).

Up 21,715 km2 from previous day.

Down 441,834 km2 over past seven days (daily average: -63,119 km2).

Down 1,177,336 km2 for the month of August (daily average: -43,605 km2).

155,932 km2 below 2000s average for this date.

560,705 km2 above 2010s average for this date.

143,885 km2 above 2013 value for this date.

1,372,069 km2 above 2012 value for this date.

8th lowest August to-date average.

8th lowest value for the date.

12 days this year (5.02% year-to-date) have recorded the lowest daily area.

21 days (8.79%) have recorded the second lowest.

17 days (7.11%) have recorded the third lowest.

50 days in total (20.92%) have been among the lowest three on record.

Wipneus · « **Reply #958 on:** August 28, 2014, 04:50:48 PM »

From area calculated from NSIDC sea ice concentration I expect the following changes of CT-area:

Fri: -16k (-)
Sat: -28k

Area drop mostly due to the CAB. Extent changes are small.

The regional breakdown is as follows:

Regional Arctic Sea Ice Extent and Area calculated from NSIDC NASA Team concentration data Date: 2014-08-27 12:00 Values in 1000 km^2 Anomalies are from the 1981-2010 mean values Extent (value, one day change, anomaly): Arctic Basin East Siberian Sea Laptev Sea 3982.3 -12.7 -320.0 313.5 -4.6 -172.5 11.5 +0.0 -272.3 Kara Sea Barents Sea Greenland Sea 154.2 -5.9 -104.8 138.1 -5.2 +85.7 165.7 -1.9 -71.7 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 26.8 -8.0 -44.4 0.0 +0.0 +0.0 37.1 -5.0 -30.7 Canadian Archipelago Beaufort Sea Chukchi Sea 532.1 +0.7 +90.5 182.1 -3.9 -103.8 14.5 +3.0 -142.1 Bering Sea Sea of Okhotsk Lakes 0.0 +0.0 -0.0 0.0 +0.0 +0.0 179.8 +26.8 +45.3 Other regions Total (ex. lakes) 0.0 +0.0 +0.0 5558.0 -43.3 -1086.1 Area (value, one day change, anomaly): Arctic Basin East Siberian Sea Laptev Sea 3183.5 -28.8 -333.9 113.1 -2.8 -189.3 4.8 +0.0 -165.5 Kara Sea Barents Sea Greenland Sea 57.9 -5.2 -86.2 64.1 -3.6 +42.8 80.7 +0.8 -29.5 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 12.9 -2.7 -19.8 0.0 +0.0 +0.0 12.5 -1.5 -10.4 Canadian Archipelago Beaufort Sea Chukchi Sea 307.1 +5.4 +47.4 99.6 +1.4 -64.0 3.3 +0.3 -77.5 Bering Sea Sea of Okhotsk Lakes 0.0 +0.0 -0.0 0.0 +0.0 +0.0 90.8 +5.6 +32.6 Other regions Total (ex. lakes) 0.0 +0.0 +0.0 3939.5 -36.8 -886.0

crandles · « **Reply #959 on:** August 28, 2014, 05:08:36 PM »

CT area with Wipneus' updates:
3.967 - 0.016 - 0.028 = 3.923

3.945 / 3.923 is 8th lowest year for area even if there is no further decline.

Next target is 3.554 so requires a further drop of 0.369

compared with same day of year:
2012.6576 -2.3640003 2.5224240
2007.6576 -1.8338246 3.0641129
2011.6576 -1.8158386 3.0820990
2008.6576 -1.6389449 3.2474794
2010.6576 -1.5504491 3.3474884
2009.6576 -1.2314339 3.6665037
2013.6576 -1.1603646 3.7375729
2014_______________3.923
2002.6576 -0.6476676 4.2502699
2005.6576 -0.6431606 4.2547770
2006.6576 -0.5867937 4.3111439

Remains 8th lowest for day.
Up to 1401k above 2012.

Losses from day .6576 to minimum and where we end if losses from now on are the same
2005   0.163   3.760
2006   0.281   3.642
2007   0.145   3.778
2008   0.244   3.679
2009   0.242   3.681
2010   0.275   3.648
2011   0.177   3.746
2012   0.288   3.635
2013   0.183   3.740
All of these would be 8th lowest year for area.


07+Average___   0.222   3.701 (8th lowest)
07+Average+3sd   0.384   3.539 (7th lowest)
07+Average+2sd   0.330   3.593 (8th lowest)
07+Average+sd_   0.276   3.647 (8th lowest)
07+Average-sd_   0.168   3.755 (8th lowest)
07+Average-2sd   0.114   3.809 (8th lowest)
07+Average-3sd   0.060   3.863 (8th lowest)

Further CT losses for 2007 onwards range is down to 0.15 to 0.3. Typical reductions like years 2007 onwards using 1sd range results in 8th lowest area, using 2sd range leads to 8th lowest area, and using 3sd deviation range leads to 7th to 8th lowest area.

Jim Pettit · « **Reply #960 on:** August 29, 2014, 01:13:06 PM »

IJIS Extent:

5,243,796 km2 (28 August)

Down 9,204,620 km2 (63.71%) from 2014 maximum of 14,448,416 km2 on 20 March.

2,066,341 km2 above record minimum extent of 3,177,455 km2 (16 September 2012).

Down 20,646 km2 from previous day.

Down 246,201 km2 over past seven days (daily average: -35,172 km2).

Down 1,519,333 km2 for the month of August (daily average: -54,262 km2).

525,262 km2 below 2000s average for this date.

470,324 km2 above 2010s average for this date.

47,781 km2 above 2013 value for this date.

1,657,121 km2 above 2012 value for this date.

7th lowest August to-date average.

7th lowest value for the date.

11 days this year (4.58% year-to-date) have recorded the lowest daily extent.

14 days (5.83%) have recorded the second lowest.

56 days (23.33%) have recorded the third lowest.

81 days (33.75%) in total have been among the three lowest on record.

CT Area:

3,946,117 km2 (28 August [Day 0.6548])

Down 9,541,220 km2 (70.74%) from 2014 maximum of 13,487,337 km2 on 22 March [Day 0.2192].

1,712,108 km2 above record minimum area of 2,234,010 km2 (14 September 2012).

Down 20,443 km2 from previous day.

Down 367,421 km2 over past seven days (daily average: -52,489 km2).

Down 1,197,779 km2 for the month of August (daily average: -42,778 km2).

184,055 km2 below 2000s average for this date.

567,101 km2 above 2010s average for this date.

179,621 km2 above 2013 value for this date.

1,376,554 km2 above 2012 value for this date.

8th lowest August to-date average.

8th lowest value for the date.

12 days this year (5.% year-to-date) have recorded the lowest daily area.

21 days (8.75%) have recorded the second lowest.

17 days (7.08%) have recorded the third lowest.

50 days in total (20.83%) have been among the lowest three on record.

Wipneus · « **Reply #961 on:** August 29, 2014, 04:34:08 PM »

From area calculated from NSIDC sea ice concentration I expect the following changes of CT-area:

Sat: -28k (-)
Sun: -67k

Area drop mostly due to the CAB. Extent changes are small.

The regional breakdown is as follows:

Regional Arctic Sea Ice Extent and Area calculated from NSIDC NASA Team concentration data Date: 2014-08-28 12:00 Values in 1000 km^2 Anomalies are from the 1981-2010 mean values Extent (value, one day change, anomaly): Arctic Basin East Siberian Sea Laptev Sea 3970.8 -11.5 -326.4 317.4 +3.9 -162.4 22.3 +10.8 -256.0 Kara Sea Barents Sea Greenland Sea 145.8 -8.4 -108.3 136.4 -1.7 +84.8 169.9 +4.2 -64.6 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 18.3 -8.5 -51.9 0.0 +0.0 +0.0 53.3 +16.2 -11.1 Canadian Archipelago Beaufort Sea Chukchi Sea 515.3 -16.7 +77.8 181.5 -0.6 -101.7 7.6 -6.9 -146.3 Bering Sea Sea of Okhotsk Lakes 0.0 +0.0 -0.0 0.0 +0.0 +0.0 210.6 +30.8 +74.6 Other regions Total (ex. lakes) 0.0 +0.0 +0.0 5538.8 -19.2 -1066.1 Area (value, one day change, anomaly): Arctic Basin East Siberian Sea Laptev Sea 3118.7 -64.8 -381.4 116.7 +3.5 -182.5 7.4 +2.6 -159.5 Kara Sea Barents Sea Greenland Sea 54.7 -3.1 -86.9 60.4 -3.7 +39.4 77.2 -3.6 -31.9 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 9.7 -3.2 -22.6 0.0 +0.0 +0.0 16.9 +4.4 -4.9 Canadian Archipelago Beaufort Sea Chukchi Sea 308.8 +1.7 +51.5 85.9 -13.7 -77.1 2.0 -1.3 -77.5 Bering Sea Sea of Okhotsk Lakes 0.0 +0.0 -0.0 0.0 +0.0 +0.0 98.3 +7.4 +39.4 Other regions Total (ex. lakes) 0.0 +0.0 +0.0 3858.5 -81.0 -933.4

crandles · « **Reply #962 on:** August 29, 2014, 05:16:15 PM »

CT area with Wipneus' updates:
3.946 - 0.028 - 0.067 = 3.851

3.945 / 3.851 is 8th lowest year for area even if there is no further decline.

Next target is 3.554 so requires a further drop of 0.297

compared with same day of year:
2012.6603 -2.3358681 2.5261645
2007.6603 -1.7700362 3.1163881
2011.6603 -1.7574863 3.1289380
2008.6603 -1.5829846 3.2790480
2010.6603 -1.5688398 3.3175845
2009.6603 -1.2478883 3.6385360
2013.6603 -1.1503243 3.7361000
2014_______________3.851
2002.6603 -0.6824238 4.2040005
2005.6603 -0.6243064 4.2621179
2006.6603 -0.6127579 4.2736664

Remains 8th lowest for day.
Down to 1325k above 2012.

Losses from day .6603 to minimum and where we end if losses from now on are the same
2005   0.170   3.681
2006   0.244   3.607
2007   0.197   3.654
2008   0.275   3.576
2009   0.214   3.637
2010   0.245   3.606
2011   0.224   3.627
2012   0.292   3.559
2013   0.182   3.669
All of these would be 8th lowest year for area though a couple are close to 7th.

07+Average___   0.233   3.618 (8th lowest)
07+Average+3sd   0.354   3.497 (7th lowest)
07+Average+2sd   0.313   3.538 (7th lowest)
07+Average+sd_   0.273   3.578 (8th lowest)
07+Average-sd_   0.192   3.659 (8th lowest)
07+Average-2sd   0.152   3.699 (8th lowest)
07+Average-3sd   0.112   3.739 (8th lowest)

Further CT losses for 2007 onwards range is down to 0.18 to 0.3. Typical reductions like years 2007 onwards using 1sd range results in 8th lowest area, using 2sd range leads to 7th to 8th lowest area, and using 3sd deviation range leads to 7th to 8th lowest area.

Getting below 3.554 to become 7th lowest year for area is a 1.6 sd event.
Getting below 3.425 to become 6th lowest year for area is a 4.8 sd event.

Jim Pettit · « **Reply #963 on:** August 30, 2014, 03:43:24 PM »

IJIS Extent:

5,217,967 km2 (29 August)

Down 9,230,449 km2 (63.89%) from 2014 maximum of 14,448,416 km2 on 20 March.

2,040,512 km2 above record minimum extent of 3,177,455 km2 (16 September 2012).

Down 25,829 km2 from previous day.

Down 222,409 km2 over past seven days (daily average: -31,773 km2).

Down 1,545,162 km2 for the month of August (daily average: -53,281 km2).

517,918 km2 below 2000s average for this date.

487,487 km2 above 2010s average for this date.

102,825 km2 above 2013 value for this date.

1,667,254 km2 above 2012 value for this date.

7th lowest August to-date average.

7th lowest value for the date.

11 days this year (4.56% year-to-date) have recorded the lowest daily extent.

14 days (5.81%) have recorded the second lowest.

56 days (23.24%) have recorded the third lowest.

81 days (33.61%) in total have been among the three lowest on record.

Wipneus · « **Reply #964 on:** August 31, 2014, 08:38:26 AM »

Belated report 20140829

From area calculated from NSIDC sea ice concentration I expect the following changes of CT-area:

Sun: -67k (-)
Mon: -82k

Area drop mostly due to the CAB. Extent declined in the CAB and Beaufort Sea, and increased in the ESS.

The regional breakdown is as follows:

Regional Arctic Sea Ice Extent and Area calculated from NSIDC NASA Team concentration data Date: 2014-08-29 12:00 Values in 1000 km^2 Anomalies are from the 1981-2010 mean values Extent (value, one day change, anomaly): Arctic Basin East Siberian Sea Laptev Sea 3947.9 -22.9 -344.5 329.5 +12.1 -144.4 14.6 -7.7 -258.8 Kara Sea Barents Sea Greenland Sea 138.0 -7.8 -111.4 136.9 +0.4 +86.1 178.4 +8.5 -53.5 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 35.3 +16.9 -33.9 0.0 +0.0 +0.0 60.8 +7.4 -0.1 Canadian Archipelago Beaufort Sea Chukchi Sea 520.9 +5.6 +87.7 164.2 -17.3 -116.6 5.1 -2.5 -146.4 Bering Sea Sea of Okhotsk Lakes 0.0 +0.0 -0.0 0.0 +0.0 +0.0 153.9 -56.7 +16.7 Other regions Total (ex. lakes) 0.0 +0.0 +0.0 5531.5 -7.3 -1035.7 Area (value, one day change, anomaly): Arctic Basin East Siberian Sea Laptev Sea 3046.4 -72.3 -439.8 119.3 +2.7 -176.7 5.9 -1.5 -158.1 Kara Sea Barents Sea Greenland Sea 52.5 -2.2 -86.7 56.8 -3.6 +36.0 82.1 +4.9 -26.1 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 15.6 +5.8 -16.5 0.0 +0.0 +0.0 17.4 +0.5 -3.3 Canadian Archipelago Beaufort Sea Chukchi Sea 310.5 +1.7 +55.7 81.5 -4.4 -80.9 1.7 -0.3 -76.7 Bering Sea Sea of Okhotsk Lakes 0.0 +0.0 -0.0 0.0 +0.0 +0.0 86.1 -12.2 +26.7 Other regions Total (ex. lakes) 0.0 +0.0 +0.0 3789.7 -68.8 -973.1

crandles · « **Reply #965 on:** August 31, 2014, 12:50:15 PM »

CT area with Wipneus' updates:
3.858 - 0.082 = 3.776

3.858 / 3.776 is 8th lowest year for area even if there is no further decline.

Next target is 3.554 so requires a further drop of 0.222

compared with same day of year:
2012.6630 -2.3517206 2.4883084
2011.6630 -1.7423078 3.1197248
2007.6630 -1.6856986 3.1763339
2008.6630 -1.5553838 3.2846451
2010.6630 -1.5395056 3.3225269
2009.6630 -1.2055780 3.6564546
2014_______________3.776
2013.6630 -1.0746490 3.7873836
2005.6630 -0.7382352 4.1237974
2002.6630 -0.7373216 4.1247110
2006.6630 -0.5624983 4.2995343

To 7th lowest for day from 8th lowest.
Down to 1288k above 2012.

Losses from day .6630 to minimum and where we end if losses from now on are the same
2005   0.032   3.744 (8th lowest)
2006   0.270   3.506 (7th lowest)
2007   0.257   3.519 (7th lowest)
2008   0.281   3.495 (7th lowest)
2009   0.232   3.544 (7th lowest)
2010   0.250   3.526 (7th lowest)
2011   0.215   3.561 ~~(7th~~8th lowest)
2012   0.254   3.522 (7th lowest)
2013   0.233   3.543 (7th lowest)

07+Average___   0.246   3.530 (7th lowest)
07+Average+3sd   0.310   3.466 (7th lowest)
07+Average+2sd   0.289   3.487 (7th lowest)
07+Average+sd_   0.267   3.509 (7th lowest)
07+Average-sd_   0.225   3.551 (7th lowest)
07+Average-2sd   0.203   3.573 (8th lowest)
07+Average-3sd   0.182   3.594 (8th lowest)

Further CT losses for 2007 onwards range is down to 0.22 to 0.28. However note that decline in 2005 was only 0.032. Therefore I do not believe the standard deviation for post 2006 years is really as low as the calculation of a mere 0.0215 which would make 2005 decline a 10sd event. So I think the ranges should be rather wider than shown above and 6th lowest year and 8th lowest year are more likely than indicated.

Earlier it seemed more appropriate to use recent years as a guide. Now we are down to a 'depends on the weather' stage I should probably include more years to give a better range of the possible. (Or maybe there is some reason for post 2006 years all showing little variation in the decline from this date just 0.22 to 0.28?)

Jim Pettit · « **Reply #966 on:** August 31, 2014, 01:53:56 PM »

IJIS Extent:

5,215,532 km2 (30 August)

Down 9,232,884 km2 (63.9%) from 2014 maximum of 14,448,416 km2 on 20 March.

2,038,077 km2 above record minimum extent of 3,177,455 km2 (16 September 2012).

Down 2,435 km2 from previous day.

Down 177,209 km2 over past seven days (daily average: -25,316 km2).

Down 1,547,597 km2 for the month of August (daily average: -51,587 km2).

489,323 km2 below 2000s average for this date.

513,418 km2 above 2010s average for this date.

132,794 km2 above 2013 value for this date.

1,677,167 km2 above 2012 value for this date.

7th lowest August to-date average.

7th lowest value for the date.

11 days this year (4.55% year-to-date) have recorded the lowest daily extent.

14 days (5.79%) have recorded the second lowest.

56 days (23.14%) have recorded the third lowest.

81 days (33.47%) in total have been among the three lowest on record.

CT Area:

3,858,251 km2 (30 August [Day 0.6603])

Down 9,629,086 km2 (71.39%) from 2014 maximum of 13,487,337 km2 on 22 March [Day 0.2192].

1,624,242 km2 above record minimum area of 2,234,010 km2 (14 September 2012).

Down 59,232 km2 from previous day.

Down 297,825 km2 over past seven days (daily average: -42,546 km2).

Down 1,285,645 km2 for the month of August (daily average: -42,855 km2).

260,082 km2 below 2000s average for this date.

544,844 km2 above 2010s average for this date.

122,151 km2 above 2013 value for this date.

1,332,087 km2 above 2012 value for this date.

8th lowest August to-date average.

8th lowest value for the date.

12 days this year (4.96% year-to-date) have recorded the lowest daily area.

21 days (8.68%) have recorded the second lowest.

17 days (7.02%) have recorded the third lowest.

50 days in total (20.66%) have been among the lowest three on record.

Wipneus · « **Reply #967 on:** August 31, 2014, 04:28:46 PM »

From area calculated from NSIDC sea ice concentration I expect the following changes of CT-area:

Mon: -82k (-)
Tue: -76k

Area drop mostly due to the CAB.

Extent declined most in the Greenland Sea.

The regional breakdown is as follows:

Regional Arctic Sea Ice Extent and Area calculated from NSIDC NASA Team concentration data Date: 2014-08-30 12:00 Values in 1000 km^2 Anomalies are from the 1981-2010 mean values Extent (value, one day change, anomaly): Arctic Basin East Siberian Sea Laptev Sea 3934.7 -13.1 -353.2 342.3 +12.8 -125.8 15.3 +0.7 -253.8 Kara Sea Barents Sea Greenland Sea 141.2 +3.3 -103.2 134.4 -2.5 +84.3 148.1 -30.3 -81.5 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 43.9 +8.6 -24.1 0.0 +0.0 +0.0 35.4 -25.3 -20.9 Canadian Archipelago Beaufort Sea Chukchi Sea 507.0 -13.9 +78.7 163.6 -0.6 -115.0 5.1 -0.0 -144.1 Bering Sea Sea of Okhotsk Lakes 0.0 +0.0 -0.1 0.0 +0.0 +0.0 135.7 -18.2 -2.7 Other regions Total (ex. lakes) 0.0 +0.0 +0.0 5471.0 -60.5 -1058.7 Area (value, one day change, anomaly): Arctic Basin East Siberian Sea Laptev Sea 2986.3 -60.2 -488.5 123.8 +4.4 -169.6 5.8 -0.1 -155.5 Kara Sea Barents Sea Greenland Sea 52.1 -0.4 -84.6 63.2 +6.4 +42.7 71.4 -10.7 -36.0 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 17.2 +1.6 -14.4 0.0 +0.0 +0.0 11.5 -6.0 -8.0 Canadian Archipelago Beaufort Sea Chukchi Sea 306.0 -4.5 +53.9 78.3 -3.2 -83.3 1.7 +0.1 -75.5 Bering Sea Sea of Okhotsk Lakes 0.0 +0.0 -0.0 0.0 +0.0 +0.0 80.0 -6.1 +20.0 Other regions Total (ex. lakes) 0.0 +0.0 +0.0 3717.3 -72.4 -1018.8

crandles · « **Reply #968 on:** August 31, 2014, 05:01:45 PM »

CT area with Wipneus' updates:
3.858 - 0.082 - 0.076 = 3.700

3.858 / 3.700 is 8th lowest year for area even if there is no further decline.

Next target is 3.554 so requires a further drop of 0.146

compared with same day of year:
2012.6658 -2.2972641 2.5100865
2011.6658 -1.7686507 3.0713782
2007.6658 -1.6936508 3.1463780
2008.6658 -1.5929682 3.2143824
2010.6658 -1.5891443 3.2508845
2009.6658 -1.2689077 3.5711212
2014_______________3.700
2013.6658 -1.0590979 3.7809310
2005.6658 -0.7482306 4.0917983
2002.6658 -0.6900841 4.1499448
2006.6658 -0.5550061 4.2850227

Remains 7th lowest for day.
Down to 1190k above 2012.

Losses from day .6658 to minimum and where we end if losses from now on are the same
2005   0.000   3.700 (8th lowest)
2006   0.255   3.445 (7th lowest)
2007   0.227   3.473 (7th lowest)
2008   0.211   3.489 (7th lowest)
2009   0.147   3.553 (7th lowest)
2010   0.179   3.521 (7th lowest)
2011   0.167   3.533 (7th lowest)
2012   0.276   3.424 (6th lowest)
2013   0.227   3.473 (7th lowest)

07+Average___   0.205   3.495 (7th lowest)
07+Average+3sd   0.336   3.364 (6th lowest)
07+Average+2sd   0.293   3.407 (6th lowest)
07+Average+sd_   0.249   3.451 (7th lowest)
07+Average-sd_   0.161   3.539 (7th lowest)
07+Average-2sd   0.117   3.583 (8th lowest)
07+Average-3sd   0.073   3.627 (8th lowest)

Further CT losses for 2007 onwards range is down to 0.15 to 0.28. However note that further decline in 2005 was only 0.0. Therefore I do not believe the standard deviation for post 2006 years is really as low as the calculation of a mere 0.0438 though this is better than yesterdays 0.0215. 2005's decline still appears to be a 5sd event. So I think the ranges could still be rather wider than shown above and 6th lowest year and 8th lowest year are more likely than indicated.

Earlier it seemed more appropriate to use recent years as a guide. Now we are down to a 'depends on the weather' stage I should probably include more years to give a better range of the possible. (Or maybe there is some reason for post 2006 years all showing little variation in the decline from this date just 0.15 to 0.28?)

BornFromTheVoid · « **Reply #969 on:** August 31, 2014, 05:54:06 PM »

Update for the week to August 30th

The current 5 day mean is on 5,553,040km2 while the 1 day extent is at 5,481,640km2.

The daily anomaly (compared to 81-10) is at -1,046,530km2, a decrease from -1,076,060km2 last week. The anomaly compared to the 07, 11 and 12 average is at 1,136,990km2, a change from +1,041,190km2 last week. We're currently 8th lowest on record, the same as last week.

The average daily change over the last 7 days was -36.7k/day, compared to the long term average of -40.9k/day, and the 07, 11 and 12 average of -50.4k/day.
The average long term change over the next week is -33.2k/day, with the 07, 11, and 12 average being -40.1k/day.

The loss in the first 30 days of August have been the 15th smallest on record. To achieve the largest August loss on record, a drop of 1.13 million km2 is required for the final day, while an average loss requires -140.5k and the smallest loss needs an increase of 392.8k.

Steven · « **Reply #970 on:** August 31, 2014, 11:59:27 PM »

Quote from: crandles on August 31, 2014, 05:01:45 PM

Earlier it seemed more appropriate to use recent years as a guide. Now we are down to a 'depends on the weather' stage I should probably include more years to give a better range of the possible. (Or maybe there is some reason for post 2006 years all showing little variation in the decline from this date just 0.15 to 0.28?)

Yes, the total CT-area loss from this date to the minimum shows little variation over the last 7 or 8 years (see graph below). Maybe it is just a coincidence. A possible alternative is to use all the years from 1979 to 2013. (In the graph below, "September 1" refers to day .6658, the same day as in Crandles' post.)

Averaged over the last 35 years, the CT area loss from September 1 to the minimum is 0.221 million km². The standard deviation is 0.113 million km². 2005 reached its minimum at this date, so for the next days the "losses to minimum" for 2005 are considered to be zero?

crandles · « **Reply #971 on:** September 01, 2014, 12:39:29 AM »

Quote from: Steven on August 31, 2014, 11:59:27 PM

2005 reached its minimum at this date, so in the next days the "losses to minimum" for 2005 are considered to be zero?

2005.6658 -0.7482306 4.0917983 annual minimum
2005.6685 -0.7064844 4.1008663 subsequent minimum 1
2005.6713 -0.6539370 4.1348834
2005.6740 -0.6460241 4.1200414
2005.6768 -0.6425690 4.1130075 subsequent minimum 2
2005.6794 -0.5982562 4.1474872 subsequent minimum 3
2005.6823 -0.5483327 4.1852565 subsequent minimum 4
2005.6849 -0.4927960 4.2329435
...
2005.7014 -0.5507690 4.1987152 subsequent minimum 5

I think it makes sense to include subsequent falls. So what you should get is

Day, ______Subsequent decline, Explanation
2005.6658 0 at min
2005.6685 0 at sm1
2005.6713 0.022 (fall to sm2)
2005.6740 0.007 (fall to sm2)
2005.6768 0 at sm2
2005.6794 0 at sm3
2005.6823 0 at sm4
2005.6849 0.034 (fall to sm5)
...
2005.7014 0 at sm5

Usually the falls are small but does get up to 95k for 2005.6931 and 80k on 2005.7123. Of course if 2014 happens to have moved to 96k higher than a previous minimum in 2014 on these dates, then these subsequent declines wouldn't cause a new 2014 minimum.

It might of course be possible to decide on a different policy, but above is what makes sense to me. This might require adjustments to my wordings to explain what I am doing.

Jim Pettit · « **Reply #972 on:** September 01, 2014, 12:56:09 PM »

IJIS Extent:

5,218,262 km2 (31 August)

Down 9,230,154 km2 (63.88%) from 2014 maximum of 14,448,416 km2 on 20 March.

2,040,807 km2 above record minimum extent of 3,177,455 km2 (16 September 2012).

Up 2,730 km2 from previous day. [NOTE: first daily increase since 29 April; largest daily increase since 05 April]

Down 120,396 km2 over past seven days (daily average: -17,199 km2).

Down 1,544,867 km2 for the month of August (daily average: -49,834 km2).

455,412 km2 below 2000s average for this date.

538,363 km2 above 2010s average for this date.

166,159 km2 above 2013 value for this date.

1,708,876 km2 above 2012 value for this date.

7th lowest August average.

7th lowest value for the date.

11 days this year (4.53% year-to-date) have recorded the lowest daily extent.

14 days (5.76%) have recorded the second lowest.

56 days (23.05%) have recorded the third lowest.

81 days (33.33%) in total have been among the three lowest on record.

CT Area:

3,777,376 km2 (31 August [Day 0.663])

Down 9,709,961 km2 (71.99%) from 2014 maximum of 13,487,337 km2 on 22 March [Day 0.2192].

1,543,366 km2 above record minimum area of 2,234,010 km2 (14 September 2012).

Down 80,875 km2 from previous day.

Down 290,562 km2 over past seven days (daily average: -41,509 km2).

Down 1,366,520 km2 for the month of August (daily average: -44,081 km2).

310,472 km2 below 2000s average for this date.

478,312 km2 above 2010s average for this date.

10,008 km2 below 2013 value for this date.

1,289,068 km2 above 2012 value for this date.

8th lowest August average.

7th lowest value for the date.

12 days this year (4.94% year-to-date) have recorded the lowest daily area.

21 days (8.64%) have recorded the second lowest.

17 days (7.%) have recorded the third lowest.

50 days in total (20.58%) have been among the lowest three on record.

Jim Pettit · « **Reply #973 on:** September 01, 2014, 01:10:44 PM »

On a related note, CT SIA dropped a total of 718k km2 over the last 12 days. That is by a substantial amount the most area ever lost over the period. Only five previous years in the record fell by as much as half-a-million km2 over the same period, and the 1979-2013 average has been about -277k. With Wipneus' current NSIDC-to-SIA forecast, that stretch of late drops is going to extend at least a few more days.

CT SIA is already lower than the minima reached in any year on the record up to and including 2006, meaning that if the melt season ended today, 2014 would have attained 8th lowest. However, the 2013 minimum is now in shouting distance, so a 7th-place finish is very possible. Not so much further along is 2009's minimum. Besting any of the remaining years are almost certainly a statistical impossibility...

Wipneus · « **Reply #974 on:** September 01, 2014, 04:06:23 PM »

From area calculated from NSIDC sea ice concentration I expect the following changes of CT-area:

Tue: -76k (-)
Wed: -8k

No significant changes in area of any of the regions.

By extent the declines in the Barents and Kara Seas are biggest (-25k and -18k).

The regional breakdown is as follows:

Regional Arctic Sea Ice Extent and Area calculated from NSIDC NASA Team concentration data Date: 2014-08-31 12:00 Values in 1000 km^2 Anomalies are from the 1981-2010 mean values Extent (value, one day change, anomaly): Arctic Basin East Siberian Sea Laptev Sea 3921.6 -13.1 -362.1 342.9 +0.7 -119.5 13.4 -1.9 -251.6 Kara Sea Barents Sea Greenland Sea 123.7 -17.6 -115.9 109.6 -24.8 +60.2 156.2 +8.1 -71.3 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 32.5 -11.4 -34.3 0.0 +0.0 +0.0 26.6 -8.8 -24.9 Canadian Archipelago Beaufort Sea Chukchi Sea 521.4 +14.4 +98.2 166.2 +2.6 -110.3 7.0 +1.9 -140.1 Bering Sea Sea of Okhotsk Lakes 0.0 +0.0 -0.1 0.0 +0.0 +0.0 149.5 +13.8 +9.7 Other regions Total (ex. lakes) 0.0 +0.0 +0.0 5421.1 -49.9 -1071.8 Area (value, one day change, anomaly): Arctic Basin East Siberian Sea Laptev Sea 2975.6 -10.6 -488.8 124.3 +0.6 -166.6 5.3 -0.5 -153.6 Kara Sea Barents Sea Greenland Sea 47.9 -4.3 -86.4 55.0 -8.3 +34.7 75.2 +3.8 -31.5 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 13.3 -3.9 -17.9 0.0 +0.0 +0.0 8.3 -3.2 -9.8 Canadian Archipelago Beaufort Sea Chukchi Sea 309.6 +3.6 +60.5 87.1 +8.8 -73.7 2.0 +0.2 -74.2 Bering Sea Sea of Okhotsk Lakes 0.0 +0.0 -0.0 0.0 +0.0 +0.0 84.1 +4.1 +23.5 Other regions Total (ex. lakes) 0.0 +0.0 +0.0 3703.5 -13.8 -1007.4

crandles · « **Reply #975 on:** September 01, 2014, 08:07:59 PM »

CT area with Wipneus' updates:
3.777 - 0.082 - 0.008 = 3.687

3.687 / 3.777 is 8th lowest year for area even if there is no further decline.

Next target is 3.554 so requires a further drop of 0.133

compared with same day of year:
2012.6685 -2.3444469 2.4443736
2011.6685 -1.8137481 2.9936025
2007.6685 -1.7288101 3.0785406
2008.6685 -1.5959958 3.1928246
2010.6685 -1.5631285 3.2442222
2009.6685 -1.2118981 3.5954525
2014_______________3.687
2013.6685 -1.0599473 3.7474034
2002.6685 -0.7256046 4.0817461

Remains 7th lowest for day.
Up to 1243k above 2012.

Losses from day .6685 to subsequent minimum and where we end if movements this year follow the pattern of that years movements.
2005   0.009   3.678 (8th lowest)
2006   0.261   3.426 (7th lowest)
2007   0.159   3.528 (7th lowest)
2008   0.189   3.498 (7th lowest)
2009   0.171   3.516 (7th lowest)
2010   0.172   3.515 (7th lowest)
2011   0.089   3.598 (8th lowest)
2012   0.210   3.477 (7th lowest)
2013   0.193   3.494 (7th lowest)

07+Average___   0.169   3.518 (7th lowest)
07+Average+3sd   0.286   3.401 (6th lowest)
07+Average+2sd   0.247   3.440 (7th lowest)
07+Average+sd_   0.208   3.479 (7th lowest)
07+Average-sd_   0.130   3.557 (8th lowest)
07+Average-2sd   0.091   3.596 (8th lowest)
07+Average-3sd   0.052   3.635 (8th lowest)

Further CT losses for 2007 onwards range is down to 0.09 to 0.21. Note that the standard deviation of post 2006 years at 0.04 is far too low compared to Stevens calculation of 0.113 for 34 years. So I think the ranges should be nearly 3 times wider than shown above and 6th lowest year and 8th lowest year are more likely than indicated. I may get around to adjusting my calculations to calculate sd of subsequent falls on 34 years rather than just post 2006 years sometime.

Steven · « **Reply #976 on:** September 02, 2014, 12:08:25 AM »

Quote from: crandles on September 01, 2014, 12:39:29 AM

I think it makes sense to include subsequent falls.

Yes, certainly. I wasn't thinking clearly...

Quote from: crandles on September 01, 2014, 08:07:59 PM

Note that the standard deviation of post 2006 years at 0.04 is far too low compared to Stephens calculation of 0.113 for 35 years. So I think the ranges should be nearly 3 times wider than shown above and 6th lowest year and 8th lowest year are more likely than indicated.

Below is a graph of the standard deviation of the losses in the last 7 vs. 35 years. Currently the 7-year standard deviation (blue curve) is about 0.04 million km², while the 35-year standard deviation (green curve) is about 0.107 million km².

Note that the 7-year standard deviation (blue) fluctuated quite a bit during the last few months: currently it's at about 0.04 million km²; on August 23 it was 0.22; on August 9 it was 0.08, etc.

The losses from Sep 1 to minimum (in the graph I posted upthread yesterday) have a weak downward trend over the last 35 years: about -0.02 million km² per decade. But the "R-square" is only 0.04, and it turns out that detrending the data (by subtracting the long-term linear trend) has very little effect on the 35-year standard deviation.

crandles · « **Reply #977 on:** September 02, 2014, 12:24:43 AM »

Thanks Steven for the graph. I might just use 0.1 as an estimate for the standard deviation for the next week or two.

Steven · « **Reply #978 on:** September 02, 2014, 01:06:12 AM »

Here are the September 1-30 values of the green curve in the graph:

Sep 1 to 5: 0.113, 0.107, 0.110, 0.115, 0.121
Sep 6 to 10: 0.110, 0.107, 0.096, 0.091, 0.088
Sep 11 to 15: 0.093, 0.101, 0.110, 0.098, 0.085
Sep 16 to 20: 0.096, 0.133, 0.096, 0.079, 0.061
Sep 21 to 25: 0.052, 0.042, 0.034, 0.028, 0.015
Sep 26 to 30: 0.018, 0.016, 0.018, 0.017, 0.009

Forgot to mention: "next minimum" in the title of the graph refers to the lowest value of CT area between the given date (on the horizontal axis of the graph) and the end of the year. So during July and August the "next minimum" is nothing but the annual CT-area minimum; but during September it can be different, at least for the dates after the annual minimum.

Jim Pettit · « **Reply #979 on:** September 02, 2014, 12:47:47 PM »

IJIS Extent:

5,213,082 km2 (01 September)

Down 9,235,334 km2 (63.92%) from 2014 maximum of 14,448,416 km2 on 20 March.

2,035,627 km2 above record minimum extent of 3,177,455 km2 (16 September 2012).

Down 5,180 km2 from previous day.

Down 91,295 km2 over past seven days (daily average: -13,042 km2).

Down 5,180 km2 for the month of September (daily average: -5,180 km2).

433,446 km2 below 2000s average for this date.

546,147 km2 above 2010s average for this date.

175,921 km2 above 2013 value for this date.

1,737,265 km2 above 2012 value for this date.

7th lowest September to-date average.

7th lowest value for the date.

11 days this year (4.51% year-to-date) have recorded the lowest daily extent.

14 days (5.74%) have recorded the second lowest.

56 days (22.95%) have recorded the third lowest.

81 days (33.2%) in total have been among the three lowest on record.

CT Area:

3,706,530 km2 (01 September [Day 0.6658])

Down 9,780,808 km2 (72.52%) from 2014 maximum of 13,487,337 km2 on 22 March [Day 0.2192].

1,472,520 km2 above record minimum area of 2,234,010 km2 (14 September 2012).

Down 70,846 km2 from previous day.

Down 317,333 km2 over past seven days (daily average: -45,333 km2).

Down 70,846 km2 for the month of September (daily average: -70,846 km2).

342,308 km2 below 2000s average for this date.

442,568 km2 above 2010s average for this date.

74,401 km2 below 2013 value for this date.

1,196,443 km2 above 2012 value for this date.

7th lowest September to-date average.

7th lowest value for the date.

12 days this year (4.92% year-to-date) have recorded the lowest daily area.

21 days (8.61%) have recorded the second lowest.

17 days (6.97%) have recorded the third lowest.

50 days in total (20.49%) have been among the lowest three on record.

Wipneus · « **Reply #980 on:** September 02, 2014, 04:13:28 PM »

From area calculated from NSIDC sea ice concentration I expect the following changes of CT-area:

Wed: -8k (-)
Thu: +5k

CAB is a big contributor (+22k) to the area change, offset by small negative changes in other regions.

By extent Beaufort makes a big drop (-20k), Greenland Sea increases (+19k).

The regional breakdown is as follows:

Regional Arctic Sea Ice Extent and Area calculated from NSIDC NASA Team concentration data Date: 2014-09-01 12:00 Values in 1000 km^2 Anomalies are from the 1981-2010 mean values Extent (value, one day change, anomaly): Arctic Basin East Siberian Sea Laptev Sea 3919.2 -2.5 -360.4 349.4 +6.5 -108.0 10.2 -3.2 -251.5 Kara Sea Barents Sea Greenland Sea 130.7 +7.1 -104.5 106.4 -3.3 +57.8 174.7 +18.6 -51.0 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 21.4 -11.0 -44.3 0.0 +0.0 +0.0 10.3 -16.3 -36.9 Canadian Archipelago Beaufort Sea Chukchi Sea 503.6 -17.8 +85.1 146.4 -19.8 -127.9 5.0 -2.0 -140.0 Bering Sea Sea of Okhotsk Lakes 0.0 +0.0 -0.1 0.0 +0.0 +0.0 150.3 +0.8 +10.0 Other regions Total (ex. lakes) 0.0 +0.0 +0.0 5377.5 -43.6 -1081.8 Area (value, one day change, anomaly): Arctic Basin East Siberian Sea Laptev Sea 2997.6 +22.0 -458.7 125.1 +0.7 -163.5 5.1 -0.3 -151.9 Kara Sea Barents Sea Greenland Sea 50.5 +2.6 -81.7 53.4 -1.5 +33.4 82.2 +7.0 -24.0 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 11.7 -1.6 -19.2 0.0 +0.0 +0.0 4.7 -3.6 -12.2 Canadian Archipelago Beaufort Sea Chukchi Sea 295.4 -14.2 +49.0 79.1 -8.0 -80.9 1.9 -0.1 -73.4 Bering Sea Sea of Okhotsk Lakes 0.0 +0.0 -0.0 0.0 +0.0 +0.0 87.3 +3.2 +26.4 Other regions Total (ex. lakes) 0.0 +0.0 +0.0 3706.6 +3.1 -983.0

Wipneus · « **Reply #981 on:** September 02, 2014, 04:54:38 PM »

I haven't posted the regional graphs for a while. Here they are with the freezing season nearby.

crandles · « **Reply #982 on:** September 03, 2014, 12:51:40 AM »

CT area with Wipneus' updates:
3.707 - 0.008 + 0.005 = 3.704

3.699 / 3.707 is 8th lowest year for area even if there is no further decline.

Next target is 3.554 so requires a further drop of 0.150

compared with same day of year:
2012.6713 -2.3938458 2.3722196
2011.6713 -1.7766131 3.0122073
2007.6713 -1.7279214 3.0608990
2008.6713 -1.6200191 3.1460464
2010.6713 -1.5888051 3.2000153
2009.6713 -1.1481949 3.6406255
2013.6713 -1.0859689 3.7028515
2014_______________3.704
2002.6713 -0.6585165 4.1303039

To 8th lowest for day (from 7th lowest).
Up to 1335k above 2012.

Losses from day .6713 to subsequent minimum and where we end if movements this year follow the pattern of that years movements.
2005   0.043   3.664 (8th lowest)
2006   0.298   3.409 (6th lowest)
2007   0.141   3.566 (8th lowest)
2008   0.142   3.565 (8th lowest)
2009   0.216   3.491 (7th lowest)
2010   0.128   3.579 (8th lowest)
2011   0.107   3.600 (8th lowest)
2012   0.138   3.569 (8th lowest)
2013   0.148   3.559 (8th lowest)

07+Average___   0.146   3.561 (8th lowest)
07+Average+3sd   0.476   3.231 (6th lowest)
07+Average+2sd   0.366   3.341 (6th lowest)
07+Average+sd_   0.256   3.451 (7th lowest)
07+Average-sd_   0.036   3.671 (8th lowest)
07+Average-2sd   -0.074   3.781 (8th lowest)
07+Average-3sd   -0.184   3.891 (8th lowest)

Further CT losses for 2007 onwards range is down to 0.1 to 0.21 using just post 2006 years. Note that I am using Stevens SD figures for all 35 years but I am using post 2006 years average decline which is inconsistent but convenient for the moment.

Typical reductions using 1sd range results in 7th to 8th lowest area, using 2sd range leads to 6th to 8th lowest area, and using 3sd deviation range leads to 6th to 8th lowest area

Jim Pettit · « **Reply #983 on:** September 03, 2014, 01:19:00 PM »

IJIS Extent:

5,200,157 km2 (02 September)

Down 9,248,259 km2 (64.01%) from 2014 maximum of 14,448,416 km2 on 20 March.

2,022,702 km2 above record minimum extent of 3,177,455 km2 (16 September 2012).

Down 12,925 km2 from previous day.

Down 78,967 km2 over past seven days (daily average: -11,281 km2).

Down 18,105 km2 for the month of September (daily average: -9,053 km2).

427,503 km2 below 2000s average for this date.

554,623 km2 above 2010s average for this date.

183,459 km2 above 2013 value for this date.

1,754,284 km2 above 2012 value for this date.

7th lowest September to-date average.

7th lowest value for the date.

11 days this year (4.49% year-to-date) have recorded the lowest daily extent.

14 days (5.71%) have recorded the second lowest.

56 days (22.86%) have recorded the third lowest.

81 days (33.06%) in total have been among the three lowest on record.

CT Area:

3,685,204 km2 (02 September [Day 0.6685])

Down 9,802,133 km2 (72.68%) from 2014 maximum of 13,487,337 km2 on 22 March [Day 0.2192].

1,451,195 km2 above record minimum area of 2,234,010 km2 (14 September 2012).

Down 21,326 km2 from previous day.

Down 259,642 km2 over past seven days (daily average: -37,092 km2).

Down 92,172 km2 for the month of September (daily average: -46,086 km2).

335,085 km2 below 2000s average for this date.

462,243 km2 above 2010s average for this date.

62,199 km2 below 2013 value for this date.

1,240,830 km2 above 2012 value for this date.

7th lowest September to-date average.

7th lowest value for the date.

12 days this year (4.9% year-to-date) have recorded the lowest daily area.

21 days (8.57%) have recorded the second lowest.

17 days (6.94%) have recorded the third lowest.

Wipneus · « **Reply #984 on:** September 03, 2014, 04:12:23 PM »

From area calculated from NSIDC sea ice concentration I expect the following changes of CT-area:

Thu: +5k (-)
Fri: -29k

CAB is the biggest contributor to the area and extent change.

The regional breakdown is as follows:

Regional Arctic Sea Ice Extent and Area calculated from NSIDC NASA Team concentration data Date: 2014-09-02 12:00 Values in 1000 km^2 Anomalies are from the 1981-2010 mean values Extent (value, one day change, anomaly): Arctic Basin East Siberian Sea Laptev Sea 3893.4 -25.8 -382.1 360.2 +10.8 -92.4 17.9 +7.7 -241.2 Kara Sea Barents Sea Greenland Sea 124.9 -5.8 -106.4 109.7 +3.3 +62.1 180.0 +5.3 -44.5 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 20.8 -0.7 -44.1 0.0 +0.0 +0.0 14.4 +4.1 -28.9 Canadian Archipelago Beaufort Sea Chukchi Sea 493.6 -10.0 +79.8 137.4 -9.0 -134.8 3.8 -1.2 -139.2 Bering Sea Sea of Okhotsk Lakes 0.0 +0.0 -0.1 0.0 +0.0 +0.0 176.7 +26.4 +36.9 Other regions Total (ex. lakes) 0.0 +0.0 +0.0 5356.2 -21.3 -1071.8 Area (value, one day change, anomaly): Arctic Basin East Siberian Sea Laptev Sea 2982.7 -14.9 -467.8 128.8 +3.7 -157.2 6.1 +1.0 -149.2 Kara Sea Barents Sea Greenland Sea 48.1 -2.4 -82.0 52.4 -1.0 +32.8 82.8 +0.6 -23.2 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 11.4 -0.3 -19.3 0.0 +0.0 +0.0 5.7 +1.0 -10.0 Canadian Archipelago Beaufort Sea Chukchi Sea 280.3 -15.1 +36.3 67.5 -11.5 -91.6 1.2 -0.6 -73.4 Bering Sea Sea of Okhotsk Lakes 0.0 +0.0 -0.0 0.0 +0.0 +0.0 93.4 +6.1 +32.7 Other regions Total (ex. lakes) 0.0 +0.0 +0.0 3667.0 -39.6 -1004.6

crandles · « **Reply #985 on:** September 03, 2014, 04:43:27 PM »

CT area with Wipneus' updates:
3.685 + 0.005 - 0.029 = 3.661

3.685 / 3.661 is 8th lowest year for area even if there is no further decline.

Next target is 3.554 so requires a further drop of 0.107

compared with same day of year:
2012.6740 -2.3790140 2.3765626
2007.6740 -1.7725419 2.9935236
2011.6740 -1.7472275 3.0188379
2010.6740 -1.6041313 3.1619341
2008.6740 -1.5772314 3.1783452
2009.6740 -1.1281060 3.6379595
2014_______________3.661
2013.6740 -1.0774010 3.6886644
2005.6740 -0.6460241 4.1200414

To 7th lowest for day (from 8th lowest).
Down to 1285k above 2012.

Losses from day .6740 to subsequent minimum and where we end if movements this year follow the pattern of that years movements.
2005   0.028   3.633 (8th lowest)
2006   0.378   3.283 (6th lowest)
2007   0.074   3.587 (8th lowest)
2008   0.175   3.486 (7th lowest)
2009   0.213   3.448 (7th lowest)
2010   0.090   3.571 (8th lowest)
2011   0.114   3.547 (7th lowest)
2012   0.143   3.518 (7th lowest)
2013   0.134   3.527 (7th lowest)

07+Average___   0.135   3.526 (7th lowest)
07+Average+3sd   0.480   3.181 (6th lowest)
07+Average+2sd   0.365   3.296 (6th lowest)
07+Average+sd_   0.250   3.411 (6th lowest)
07+Average-sd_   0.020   3.641 (8th lowest)
07+Average-2sd   -0.095   3.756 (8th lowest)
07+Average-3sd   -0.210   3.871 (8th lowest)

Further CT losses for 2007 onwards range is down to 0.07 to 0.21 using just post 2006 years. Note that I am using Stevens SD figures for all 35 years but I am using post 2006 years average decline which is inconsistent but convenient for the moment.

Typical reductions using 1sd range results in 6th to 8th lowest area, using 2sd range leads to 6th to 8th lowest area, and using 3sd deviation range leads to 6th to 8th lowest area.

Jim Pettit · « **Reply #986 on:** September 04, 2014, 12:36:33 PM »

IJIS Extent:

5,179,456 km2 (03 September)

Down 9,268,960 km2 (64.15%) from 2014 maximum of 14,448,416 km2 on 20 March.

2,002,001 km2 above record minimum extent of 3,177,455 km2 (16 September 2012).

Down 20,701 km2 from previous day.

Down 84,986 km2 over past seven days (daily average: -12,141 km2).

Down 38,806 km2 for the month of September (daily average: -12,935 km2).

434,181 km2 below 2000s average for this date.

565,869 km2 above 2010s average for this date.

189,535 km2 above 2013 value for this date.

1,734,245 km2 above 2012 value for this date.

7th lowest September to-date average.

7th lowest value for the date.

11 days this year (4.47% year-to-date) have recorded the lowest daily extent.

14 days (5.69%) have recorded the second lowest.

56 days (22.76%) have recorded the third lowest.

81 days (32.93%) in total have been among the three lowest on record.

CT Area:

3,677,823 km2 (03 September [Day 0.6713])

Down 9,809,514 km2 (72.73%) from 2014 maximum of 13,487,337 km2 on 22 March [Day 0.2192].

1,443,814 km2 above record minimum area of 2,234,010 km2 (14 September 2012).

Down 7,381 km2 from previous day.

Down 288,738 km2 over past seven days (daily average: -41,248 km2).

Down 99,553 km2 for the month of September (daily average: -33,184 km2).

323,055 km2 below 2000s average for this date.

484,800 km2 above 2010s average for this date.

25,028 km2 below 2013 value for this date.

1,305,604 km2 above 2012 value for this date.

7th lowest September to-date average.

7th lowest value for the date.

12 days this year (4.88% year-to-date) have recorded the lowest daily area.

21 days (8.54%) have recorded the second lowest.

17 days (6.91%) have recorded the third lowest.

50 days in total (20.33%) have been among the lowest three on record.

Wipneus · « **Reply #987 on:** September 04, 2014, 04:49:34 PM »

From area calculated from NSIDC sea ice concentration I expect the following changes of CT-area:

Fri: -29k (-)
Sat: -21k

CAB is the biggest contributor to the area change.

The CAA and Kara significantly increase extent.

The regional breakdown is as follows:

Regional Arctic Sea Ice Extent and Area calculated from NSIDC NASA Team concentration data Date: 2014-09-03 12:00 Values in 1000 km^2 Anomalies are from the 1981-2010 mean values Extent (value, one day change, anomaly): Arctic Basin East Siberian Sea Laptev Sea 3876.3 -17.1 -395.1 354.5 -5.7 -93.6 10.2 -7.7 -246.9 Kara Sea Barents Sea Greenland Sea 138.5 +13.6 -89.2 112.3 +2.6 +65.8 166.3 -13.8 -57.4 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 31.6 +10.8 -32.4 0.0 +0.0 +0.0 14.0 -0.5 -25.4 Canadian Archipelago Beaufort Sea Chukchi Sea 528.3 +34.7 +119.2 135.6 -1.9 -134.8 3.2 -0.6 -137.8 Bering Sea Sea of Okhotsk Lakes 0.0 +0.0 -0.2 0.0 +0.0 +0.0 165.7 -11.0 +27.2 Other regions Total (ex. lakes) 0.0 +0.0 +0.0 5370.6 +14.4 -1027.8 Area (value, one day change, anomaly): Arctic Basin East Siberian Sea Laptev Sea 2955.8 -26.9 -490.7 128.8 -0.0 -154.5 4.6 -1.5 -149.4 Kara Sea Barents Sea Greenland Sea 52.1 +4.0 -76.1 55.7 +3.3 +36.5 76.4 -6.4 -29.6 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 13.9 +2.5 -16.6 0.0 +0.0 +0.0 5.7 +0.0 -8.8 Canadian Archipelago Beaufort Sea Chukchi Sea 284.1 +3.8 +42.7 71.2 +3.6 -87.1 1.0 -0.2 -73.0 Bering Sea Sea of Okhotsk Lakes 0.0 +0.0 -0.0 0.0 +0.0 +0.0 90.1 -3.3 +30.0 Other regions Total (ex. lakes) 0.0 +0.0 +0.0 3649.3 -17.7 -1006.8

crandles · « **Reply #988 on:** September 04, 2014, 06:20:36 PM »

CT area with Wipneus' updates:
3.678 - 0.029 - 0.021 = 3.628

3.678 / 3.628 is 8th lowest year for area even if there is no further decline.

Next target is 3.554 so requires a further drop of 0.074

compared with same day of year:
2012.6768 -2.3822103 2.3635330
2011.6768 -1.7537520 3.0018246
2007.6768 -1.7422707 3.0133059
2008.6768 -1.6474488 3.0982945
2010.6768 -1.5608788 3.1946979
2009.6768 -1.1723168 3.5832598
2013.6768 -1.1277027 3.6278739
2014_______________3.628
2002.6768 -0.6670317 4.0885448

To 8th lowest for day (from 7th lowest).
Down to 1264k above 2012.

Losses from day .6768 to subsequent minimum and where we end if movements this year follow the pattern of that years movements.
2005   0.021   3.607 (8th lowest)
2006   0.339   3.289 (6th lowest)
2007   0.094   3.534 (7th lowest)
2008   0.095   3.533 (7th lowest)
2009   0.159   3.469 (7th lowest)
2010   0.123   3.505 (7th lowest)
2011   0.097   3.531 (7th lowest)
2012   0.130   3.498 (7th lowest)
2013   0.073   3.555 (8th lowest)

07+Average___   0.110   3.518 (7th lowest)
07+Average+3sd   0.473   3.155 (6th lowest)
07+Average+2sd   0.352   3.276 (6th lowest)
07+Average+sd_   0.231   3.397 (6th lowest)
07+Average-sd_   -0.011   3.639 (8th lowest)
07+Average-2sd   -0.132   3.760 (8th lowest)
07+Average-3sd   -0.253   3.881 (8th lowest)

Further CT losses for 2007 onwards range is down to 0.07 to 0.16 using just post 2006 years. Note that I am using Stevens SD figures for all 35 years but I am using post 2006 years average decline which is inconsistent but convenient for the moment.

Typical reductions using 1sd range results in 6th to 8th lowest area, using 2sd range leads to 6th to 8th lowest area, and using 3sd deviation range leads to 6th to 8th lowest area.

Jim Pettit · « **Reply #989 on:** September 05, 2014, 12:53:16 PM »

IJIS Extent:

5,142,812 km2 (04 September)

Down 9,305,604 km2 (64.41%) from 2014 maximum of 14,448,416 km2 on 20 March.

1,965,357 km2 above record minimum extent of 3,177,455 km2 (16 September 2012).

Down 36,644 km2 from previous day.

Down 100,984 km2 over past seven days (daily average: -14,426 km2).

Down 75,450 km2 for the month of September (daily average: -18,863 km2).

446,701 km2 below 2000s average for this date.

568,266 km2 above 2010s average for this date.

185,078 km2 above 2013 value for this date.

1,728,762 km2 above 2012 value for this date.

7th lowest September to-date average.

7th lowest value for the date.

11 days this year (4.45% year-to-date) have recorded the lowest daily extent.

14 days (5.67%) have recorded the second lowest.

56 days (22.67%) have recorded the third lowest.

81 days (32.79%) in total have been among the three lowest on record.

CT Area:

3,645,369 km2 (04 September [Day 0.674])

Down 9,841,969 km2 (72.97%) from 2014 maximum of 13,487,337 km2 on 22 March [Day 0.2192].

1,411,359 km2 above record minimum area of 2,234,010 km2 (14 September 2012).

Down 32,455 km2 from previous day.

Down 300,749 km2 over past seven days (daily average: -42,964 km2).

Down 132,007 km2 for the month of September (daily average: -33,002 km2).

344,973 km2 below 2000s average for this date.

467,095 km2 above 2010s average for this date.

43,296 km2 below 2013 value for this date.

1,268,806 km2 above 2012 value for this date.

7th lowest September to-date average.

7th lowest value for the date.

12 days this year (4.86% year-to-date) have recorded the lowest daily area.

21 days (8.5%) have recorded the second lowest.

17 days (6.88%) have recorded the third lowest.

50 days in total (20.24%) have been among the lowest three on record.

Wipneus · « **Reply #990 on:** September 05, 2014, 05:20:46 PM »

From area calculated from NSIDC sea ice concentration I expect the following changes of CT-area:

Sat: -21k (-)
Sun: -47k

CAB is the biggest contributor to the area change.

The CAA and Kara significantly decline extent (opposite yesterday), ESS increases.

The regional breakdown is as follows:

Regional Arctic Sea Ice Extent and Area calculated from NSIDC NASA Team concentration data Date: 2014-09-04 12:00 Values in 1000 km^2 Anomalies are from the 1981-2010 mean values Extent (value, one day change, anomaly): Arctic Basin East Siberian Sea Laptev Sea 3873.6 -2.7 -394.0 372.4 +17.9 -71.7 10.8 +0.6 -244.7 Kara Sea Barents Sea Greenland Sea 114.5 -24.0 -110.0 110.2 -2.0 +64.9 153.2 -13.0 -69.8 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 27.3 -4.2 -35.9 0.0 +0.0 +0.0 12.2 -1.8 -23.6 Canadian Archipelago Beaufort Sea Chukchi Sea 501.5 -26.8 +96.8 138.7 +3.2 -129.6 2.5 -0.6 -136.6 Bering Sea Sea of Okhotsk Lakes 0.0 +0.0 -0.2 0.0 +0.0 +0.0 151.8 -13.9 +14.7 Other regions Total (ex. lakes) 0.0 +0.0 +0.0 5317.1 -53.6 -1054.5 Area (value, one day change, anomaly): Arctic Basin East Siberian Sea Laptev Sea 2922.2 -33.6 -521.7 139.9 +11.1 -141.2 4.8 +0.1 -148.4 Kara Sea Barents Sea Greenland Sea 45.3 -6.8 -81.3 55.9 +0.2 +37.2 74.1 -2.3 -32.1 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 12.4 -1.5 -18.0 0.0 +0.0 +0.0 5.6 -0.1 -7.9 Canadian Archipelago Beaufort Sea Chukchi Sea 272.2 -12.0 +33.0 70.6 -0.5 -86.8 0.9 -0.1 -72.6 Bering Sea Sea of Okhotsk Lakes 0.0 +0.0 -0.0 0.0 +0.0 +0.0 87.2 -2.9 +27.6 Other regions Total (ex. lakes) 0.0 +0.0 +0.0 3603.9 -45.4 -1039.8

crandles · « **Reply #991 on:** September 05, 2014, 06:15:07 PM »

CT area with Wipneus' updates:
3.645 - 0.021 -0.047 = 3.577

3.678 / 3.628 is 8th lowest year for area even if there is no further decline.

Next target is 3.554 so requires a further drop of 0.023 (less than half the latest drop).
Following target is 3.425 so requires a further drop of 0.152

compared with same day of year:
2012.6794 -2.3834982 2.3500910
2011.6794 -1.7693100 2.9764333
2007.6794 -1.7643862 2.9813571
2008.6794 -1.6265607 3.1070285
2010.6794 -1.5989542 3.1467891
2009.6794 -1.1708345 3.5749087
2014_______________3.577
2013.6794 -1.1211905 3.6245527

To 7th lowest for day (from 8th lowest).
Down to 1227k above 2012.

Losses from day .6794 to subsequent minimum and where we end if movements this year follow the pattern of that years movements.
2005   0.056   3.521 (7th lowest)
2006   0.303   3.274 (6th lowest)
2007   0.062   3.515 (7th lowest)
2008   0.103   3.474 (7th lowest)
2009   0.150   3.427 (7th lowest)
2010   0.075   3.502 (7th lowest)
2011   0.072   3.505 (7th lowest)
2012   0.116   3.461 (7th lowest)
2013   0.070   3.507 (7th lowest)

07+Average____   0.093   3.484 (7th lowest)
07+Average+3sd   0.423   3.154 (6th lowest)
07+Average+2sd   0.313   3.264 (6th lowest)
07+Average+sd_   0.203   3.374 (6th lowest)
07+Average-sd_   -0.017   3.594 (8th lowest)
07+Average-2sd   -0.127   3.704 (8th lowest)
07+Average-3sd   -0.237   3.814 (8th lowest)

Further CT losses for 2007 onwards range is down to 0.06 to 0.15 using just post 2006 years. Note that I am using Stevens SD figures for all 35 years but I am using post 2006 years average decline which is inconsistent but convenient for the moment.

Typical reductions using 1sd range results in 6th to 8th lowest area, using 2sd range leads to 6th to 8th lowest area, and using 3sd deviation range leads to 6th to 8th lowest area.

deep octopus · « **Reply #992 on:** September 05, 2014, 06:45:41 PM »

One-day NSIDC extent is brushing very closely with the 2005 daily minimum, with a difference of only 8,790 km². I wholly expect 2014 to drop below the 2005 minimum any day now. It's almost certain that the September average will be less than the 2005 September average as well, though having been positioned slightly above 2009 and 2013 for a while, may well remain above them for the majority of the month. In addition, it would take a 250,000 km² drop for the extent to match the 2013 daily minimum, and another 20,000 km² to match 2009's daily minimum. This is looking to be an increasingly unlikely feat.

I now expect that the extent (whether looking at single-day minimum or the average) of 2014 will finish in 8th place (therefore, less than 2005, but above 2009 and 2013), whereas area is well-positioned to be in 7th place (thus, below 2013, but above 2009), which is just as well.

Jim Pettit · « **Reply #993 on:** September 06, 2014, 02:14:44 PM »

IJIS Extent:

5,092,841 km2 (05 September)

Down 9,355,575 km2 (64.75%) from 2014 maximum of 14,448,416 km2 on 20 March.

1,915,386 km2 above record minimum extent of 3,177,455 km2 (16 September 2012).

Down 49,971 km2 from previous day.

Down 125,126 km2 over past seven days (daily average: -17,875 km2).

Down 125,421 km2 for the month of September (daily average: -25,084 km2).

474,742 km2 below 2000s average for this date.

559,666 km2 above 2010s average for this date.

150,602 km2 above 2013 value for this date.

1,726,848 km2 above 2012 value for this date.

7th lowest September to-date average.

7th lowest value for the date.

11 days this year (4.44% year-to-date) have recorded the lowest daily extent.

14 days (5.65%) have recorded the second lowest.

56 days (22.58%) have recorded the third lowest.

81 days (32.66%) in total have been among the three lowest on record.

Wipneus · « **Reply #994 on:** September 06, 2014, 04:18:56 PM »

From area calculated from NSIDC sea ice concentration I expect the following changes of CT-area:

Sun: -47k (-)
Mon: +24k

CAB is the biggest contributor with a big uptick in area (+37k) partly offset by the ESS (-15k).

The CAA, ESS and Kara significantly decline in extent, in the Beaufort extent increases.

The regional breakdown is as follows:

Regional Arctic Sea Ice Extent and Area calculated from NSIDC NASA Team concentration data Date: 2014-09-05 12:00 Values in 1000 km^2 Anomalies are from the 1981-2010 mean values Extent (value, one day change, anomaly): Arctic Basin East Siberian Sea Laptev Sea 3865.7 -7.9 -398.1 356.4 -16.0 -84.4 8.3 -2.6 -246.3 Kara Sea Barents Sea Greenland Sea 99.5 -15.0 -122.2 102.4 -7.8 +58.1 154.6 +1.3 -68.0 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 20.7 -6.6 -42.0 0.0 +0.0 +0.0 10.9 -1.3 -22.2 Canadian Archipelago Beaufort Sea Chukchi Sea 462.7 -38.8 +61.3 154.6 +15.8 -111.5 2.5 +0.0 -134.9 Bering Sea Sea of Okhotsk Lakes 0.0 +0.0 -0.2 0.0 +0.0 +0.0 167.1 +15.4 +30.8 Other regions Total (ex. lakes) 0.0 +0.0 +0.0 5238.4 -78.7 -1110.1 Area (value, one day change, anomaly): Arctic Basin East Siberian Sea Laptev Sea 2959.4 +37.2 -482.9 125.3 -14.5 -154.2 4.0 -0.8 -148.8 Kara Sea Barents Sea Greenland Sea 41.3 -4.1 -84.1 55.9 +0.0 +37.6 75.2 +1.1 -31.4 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 11.8 -0.6 -18.6 0.0 +0.0 +0.0 5.2 -0.4 -7.5 Canadian Archipelago Beaufort Sea Chukchi Sea 265.9 -6.3 +28.4 79.7 +9.0 -76.7 0.9 -0.1 -72.2 Bering Sea Sea of Okhotsk Lakes 0.0 +0.0 -0.0 0.0 +0.0 +0.0 91.4 +4.2 +32.1 Other regions Total (ex. lakes) 0.0 +0.0 +0.0 3624.5 +20.6 -1010.4

crandles · « **Reply #995 on:** September 06, 2014, 04:37:08 PM »

CT area with Wipneus' updates:
3.626 -0.047 = 3.579 + 0.024 = 3.603

3.626 / 3.579 / 3.603 is 8th lowest year for area even if there is no further decline.

Next target is 3.554 so requires a further drop of 0.049.
Following target is 3.425 so requires a further drop of 0.178

compared with same day of year:
2012.6823 -2.4275291 2.2982104
2011.6823 -1.8160963 2.9174929
2007.6823 -1.7964566 2.9371326
2008.6823 -1.6755341 3.0502055
2010.6823 -1.6237273 3.1098619
2009.6823 -1.1407342 3.5928550
2013.6823 -1.1417730 3.5918162
2014_______________3.603
2002.6823 -0.6988788 4.0347104

To 8th lowest for day (from 7th lowest).
Up to 1305k above 2012.

Losses from day .6823 to subsequent minimum and where we end if movements this year follow the pattern of that years movements.
2005   ~~0.093   3.510 (7th lowest)~~ 0 3.603 (8th lowest)
2006 ~~0.294   3.309 (6th lowest)~~ 0.306 3.297 (6th lowest)
2007   0.018   3.585 (8th lowest)
2008   0.047   3.556 (8th lowest)
2009   0.168   3.435 (7th lowest)
2010   0.038   3.565 (8th lowest)
2011   0.013   3.590 (8th lowest)
2012   0.064   3.539 (7th lowest)
2013   0.037   3.566 (8th lowest)

07+Average____   0.055   3.548 (7th lowest)
07+Average+3sd   0.385   3.218 (6th lowest)
07+Average+2sd   0.275   3.328 (6th lowest)
07+Average+sd_   0.165   3.438 (7th lowest)
07+Average-sd_   -0.055   3.658 (8th lowest)
07+Average-2sd   -0.165   3.768 (8th lowest)
07+Average-3sd   -0.275   3.878 (8th lowest)

Further CT losses for 2007 onwards range is down to 0.02 to 0.17 using just post 2006 years. Note that I am using Stevens SD figures for all 35 years but I am using post 2006 years average decline which is inconsistent but convenient for the moment.

Typical reductions using 1sd range results in 7th to 8th lowest area, using 2sd range leads to 6th to 8th lowest area, and using 3sd deviation range leads to 6th to 8th lowest area.

Yesterday, seemed almost certain to get down to 7th lowest year for area. Just one day later and 5 out of last 7 years' movements wouldn't get down to 7th lowest.

Thanks to Steven for corrections.

Jim Pettit · « **Reply #996 on:** September 07, 2014, 02:36:21 PM »

IJIS Extent:

5,050,369 km2 (06 September)

Down 9,398,047 km2 (65.05%) from 2014 maximum of 14,448,416 km2 on 20 March.

1,872,914 km2 above record minimum extent of 3,177,455 km2 (16 September 2012).

Down 42,472 km2 from previous day.

Down 165,163 km2 over past seven days (daily average: -23,595 km2).

Down 167,893 km2 for the month of September (daily average: -27,982 km2).

497,367 km2 below 2000s average for this date.

554,474 km2 above 2010s average for this date.

126,397 km2 above 2013 value for this date.

1,725,131 km2 above 2012 value for this date.

7th lowest September to-date average.

7th lowest value for the date.

11 days this year (4.42% year-to-date) have recorded the lowest daily extent.

14 days (5.62%) have recorded the second lowest.

56 days (22.49%) have recorded the third lowest.

81 days (32.53%) in total have been among the three lowest on record.

CT Area:

3,583,640 km2 (06 September [Day 0.6794])

Down 9,903,697 km2 (73.43%) from 2014 maximum of 13,487,337 km2 on 22 March [Day 0.2192].

1,349,631 km2 above record minimum area of 2,234,010 km2 (14 September 2012).

Down 42,622 km2 from previous day.

Down 274,611 km2 over past seven days (daily average: -39,230 km2).

Down 193,736 km2 for the month of September (daily average: -32,289 km2).

393,805 km2 below 2000s average for this date.

447,339 km2 above 2010s average for this date.

40,913 km2 below 2013 value for this date.

1,233,549 km2 above 2012 value for this date.

7th lowest September to-date average.

7th lowest value for the date.

12 days this year (4.82% year-to-date) have recorded the lowest daily area.

21 days (8.43%) have recorded the second lowest.

17 days (6.83%) have recorded the third lowest.

50 days in total (20.08%) have been among the lowest three on record.

Wipneus · « **Reply #997 on:** September 07, 2014, 05:11:10 PM »

From area calculated from NSIDC sea ice concentration I expect the following changes of CT-area:

Mon: +24k (-)
Tue: -23k

It is the CAB and ESS that contribute most to that decline, despite a big increase of "lake ice" (+16k).

By extent it is mostly the ESS that does it. The huge increase in "lake ice" (+68k) is wisely not included in the NSIDC sea ice extent.

The regional breakdown is as follows:

Regional Arctic Sea Ice Extent and Area calculated from NSIDC NASA Team concentration data Date: 2014-09-06 12:00 Values in 1000 km^2 Anomalies are from the 1981-2010 mean values Extent (value, one day change, anomaly): Arctic Basin East Siberian Sea Laptev Sea 3857.2 -8.5 -402.5 333.1 -23.3 -105.0 9.6 +1.3 -244.7 Kara Sea Barents Sea Greenland Sea 86.5 -13.0 -133.0 109.0 +6.6 +65.7 157.8 +3.2 -64.1 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 25.8 +5.1 -36.4 0.0 +0.0 +0.0 14.6 +3.7 -17.0 Canadian Archipelago Beaufort Sea Chukchi Sea 472.3 +9.6 +73.6 148.8 -5.7 -114.3 2.5 +0.0 -133.2 Bering Sea Sea of Okhotsk Lakes 0.0 +0.0 -0.2 0.0 +0.0 +0.0 235.5 +68.4 +99.3 Other regions Total (ex. lakes) 0.0 +0.0 +0.0 5217.3 -21.1 -1111.2 Area (value, one day change, anomaly): Arctic Basin East Siberian Sea Laptev Sea 2933.3 -26.1 -509.2 108.0 -17.4 -170.7 4.8 +0.8 -148.0 Kara Sea Barents Sea Greenland Sea 38.2 -3.0 -86.2 55.9 -0.0 +37.9 76.1 +1.0 -30.7 Baffin/Newfoundland Bay St. Lawrence Hudson Bay 14.0 +2.2 -16.4 0.0 +0.0 +0.0 6.7 +1.5 -5.5 Canadian Archipelago Beaufort Sea Chukchi Sea 263.1 -2.7 +27.1 77.5 -2.2 -77.7 0.9 +0.0 -71.8 Bering Sea Sea of Okhotsk Lakes 0.0 +0.0 -0.0 0.0 +0.0 +0.0 107.7 +16.3 +48.5 Other regions Total (ex. lakes) 0.0 +0.0 +0.0 3578.6 -45.9 -1051.2

crandles · « **Reply #998 on:** September 07, 2014, 06:14:15 PM »

CT area with Wipneus' updates:
3.584 + 0.024 - 0.023 = 3.585

3.584 / 3.585 is 8th lowest year for area even if there is no further decline.

Next target is 3.554 so requires a further drop of 0.031 (14 of last 25 years 56% do larger subsequent declines.)
Following target is 3.425 so requires a further drop of 0.160 (6 of last 25 years 24% do larger subsequent declines.)

compared with same day of year:
2012.6849 -2.4267466 2.2937613
2007.6849 -1.8063005 2.9194391
2011.6849 -1.7806035 2.9451361
2008.6849 -1.6914377 3.0290701
2010.6849 -1.6380459 3.0876937
2009.6849 -1.1864814 3.5392582
2013.6849 -1.1540672 3.5716724
2014_______________3.585
2002.6849 -0.6890846 4.0366550

Remains 8th lowest for day.
Down to 1291k above 2012.

Losses from day .6849 to subsequent minimum and where we end if movements this year follow the pattern of that years movements.
2005   0.034   3.551 (7th lowest)
2006   0.227   3.358 (6th lowest)
2007   0.000   3.585 (8th lowest)
2008   0.026   3.559 (8th lowest)
2009   0.115   3.470 (7th lowest)
2010   0.016   3.569 (8th lowest)
2011   0.040   3.545 (7th lowest)
2012   0.060   3.525 (7th lowest)
2013   0.017   3.568 (8th lowest)

07+Average____   0.039   3.546 (7th lowest)
07+Average+3sd   0.296   3.289 (6th lowest)
07+Average+2sd   0.210   3.375 (6th lowest)
07+Average+sd_   0.125   3.460 (7th lowest)
07+Average-sd_   -0.046   3.631 (8th lowest)
07+Average-2sd   -0.132   3.717 (8th lowest)
07+Average-3sd   -0.218   3.803 (8th lowest)

Further CT losses for 2007 onwards range is down to 0.0 to 0.12 using just post 2006 years.
Note that I am now using the last 20 years for average subsequent decline of 0.075 and standard deviation of 0.0855

Typical reductions using 1sd range results in 7th to 8th lowest area, using 2sd range leads to 6th to 8th lowest area, and using 3sd deviation range leads to 6th to 8th lowest area.

jdallen · « **Reply #999 on:** September 08, 2014, 08:01:15 AM »

Quote from: crandles on September 07, 2014, 06:14:15 PM

CT area with Wipneus' updates:
<snippage>
2010.6849 -1.6380459 3.0876937
2009.6849 -1.1864814 3.5392582
2013.6849 -1.1540672 3.5716724
2014_______________3.585
2002.6849 -0.6890846 4.0366550

The differences between 2014, 2013 and 2009 are close to being statistically insignificant, considering measurement error probability.

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Author Topic: 2014 sea ice area and extent data (Read 651513 times)