Many interesting posts this morning, I'm making a bulk response.
Looks like 3,000km or more of fast ice just broke free of NE Greenland by the polynya.
https://go.nasa.gov/2uoILzQ
Nice spotting stackmaster.
For what it's worth, this animation more or less shows the difference in extent for 2016 and 17 for this day (from Polar Portal) A bit rough, but, ie. 2016 extent that 2017 does not have, and 2017 extent that 2016 did not have.
Thanks for this TB. Great animation. 2016 had all the advantage on the Atlantic side, which I believe is relatively easy ice that will go anyway this year. Therefore 2017 has much less chance of stalling like 2016 did.
One aspect of this part of the melting season I do not have a good grasp of is the 'practical' relation of sea ice area (SIA) and sea ice extent (SIE). I know it is 'all about' grid size, but that's 'theory' to me. In practical terms, can someone show a 'real live' grid with 15% SIA so I can see what it looks like? For example, when we look at the North Pole to Greenland image, how many grids are along the 30W longitude line? (10s or 1000s?) Off the NE corner of Greenland, are there ice-free grids right now? (If so, about how many?)
Tor, this depends on the grid. the distance from the North pole to Kap Moris Jesup (northernmost Greenland point) is 711 km. In NSIDC (25km grid) you get <30 grid points covering this distance. In AMSR2 (3.25km grid) you get >200 grid points. Wipneus' wonderful AMSR2 animations on the home brew thread give a grasp of the level of detail of this grid, almost better than sat images.
You can easily understand the meaning of the coarser grids by toggling sea ice concentration in worldview, one of the layers gives you the 25km grid concentration, there's another giving you a 12 km AMSR concentration, toggle it against the actual images. Check out Nares for example.
JAXA volume just dropped to about 6,000 km3, which is surprisingly low when you consider the JAXA average thickness of Arctic sea ice.
Compare to PIOMAS average thickness.
TT, JAXA volume is quite meaningless at this time of year, and certainly not comparable to PIOMAS. The satellite cannot measure ice thickness in summer, and only partially in winter IIRC.