@JimHunt
Estimate of likely course of melt season using the following graph from DOSBAT.
http://dosbat.blogspot.com.au/2014/05/piomas-april-2014-gridded-data.htmlThe volume of ice for each thickness band was estimated using a crude measurement from the graph. The area of ice this represents was calculated Volume / Thickness. Dates are estimates by correlating against actual declines over the past three years. The melt rate based on thickness has been fairly consistent over this time.
April Ice
Thickness Estimated Volume (km3) Estimated Area (Kkm2)
(cm) 2011 2012 2013 2014 2011 2012 2013 2014
0.05 30 30 30 30 600 600 600 600
0.15 60 60 50 60 400 400 333 400
0.25 90 90 70 90 360 360 280 360
0.35 100 125 90 100 286 357 257 286
0.45 160 160 140 125 356 356 311 278
Jun 1 Estimate Total Loss 2001 2073 1782 1923
0.55 210 210 160 125 382 382 291 227
0.65 210 240 180 160 323 369 277 246
0.75 160 375 260 210 213 500 347 280
Jun 15 Estimated loss previous 2 weeks 918 1251 915 753
0.85 240 430 260 240 282 506 306 282
0.95 300 320 280 260 316 337 295 274
1.05 430 270 330 375 410 257 314 357
1.15 450 375 450 500 391 326 391 435
1.25 500 620 680 450 400 496 544 360
Jul 1 Estimated loss previous 2 weeks 1799 1922 1950 1708
1.35 625 770 700 625 463 570 519 463
1.45 720 1000 720 720 497 690 497 497
1.55 1000 900 750 670 645 581 484 432
Jul 15 Estimated loss previous 2 weeks 1605 1841 1499 1392
1.65 950 830 550 950 576 503 333 576
1.75 1250 750 1250 1950 714 429 714 1114
1.85 1670 875 1500 2250 903 473 811 1216
Aug 1st Estimated loss previous 2 weeks 2193 1405 1858 2906
Aug 1st Total accumulated loss 8516 8491 7904 8683
1.95 2000 740 2600 2000 1026 379 1333 1026
2.05 1450 950 2650 1550 707 463 1293 756
2.15 1950 1150 1150 1500 907 535 535 698
2.25 1350 1500 975 1250 600 667 433 556
2.35 850 2100 1000 750 362 894 426 319
Based on these figures we can see that with thickness loss at the rate of the past three years, 2014 ice extent will be above the other three years until the ice has lost an average 1.55m of thickness. From 1.55 to 1.85 m loss however, 2014 will catch and surpass the other three years. All of the past three years have lost more than 1.85 m of thickness. The final figure will be dependent on the total thickness loss, however 2012 appears to have lost about 2.30 m, which if repeated would put the final figure in the region 2-2.5 MKm2, even 2.10m will surpass the 2012 final figures.