more interest to track a floe that disintegrates to see how much of it can be accounted for.
That's a hard way to go. For starters, imagery for that does not exist (short of paying for hugely expensive commercial satellite coverage). Even if it did, substantial cloud cover, variably thick and thin, often interferes for many days in a row.
If one pixel on the best available daily optical image is 250 m pixels on a side, it would not be feasible to follow a floe quantitatively below a few sq km in area. As small floes change appearance and mingle with other pieces, they become difficult to track reliably.
Higher resolution imagery such as Sentinel 2A at 10 m, has an orbital return time of ten days. Make that 20, 30 or more considering clouds for comparable viewing geometry. The coverage of the Beaufort Sea by S2A is largely circum-coastal, meaning floes will drift out of view in successive images. Sentinel 1A radar penetrates the clouds ok but presents similar issues.
Even if the resolution were at hand, the area of a five sq km floe is mostly interior with little periphery. If the water is so cold that it is not melting off (or capable of abrading) the edges of the larger floes, why then is it warm enough to melt the edges off the smaller floes?
In past years, we've looked at how peripheral area grows with floe fragmentation relative to (fixed) floe bottom area -- not very fast because non-freeboard ice is just a meter or two thick.
While floe fracturing on the edge of the Beaufort Gyre is a significant process, it is not seen so often in more interior floes (where most of the ice is). The fracturing there happens early on when very large rigid blocks are torqued. After the initial events, no mechanism remains to transmit force to free-floating pieces other than waves, but here the fetch is too short, unlike that now along the Alaskan coast.
JimH posted a very interesting account yesterday of wave action observed by researchers fortuitously on the scene with deployed instrumentation. The usual dramatic mechanical break-up was seen but the actual consequential impact came from wave action bringing up warm water from 25 m depth. Which makes one wonder about those ubiquitous deep & stable Atlantic Water cartoons of the Arctic Ocean.
By coincidence I have been tracking the smaller floe just south (on the 27th) of the one measured above
By coincidence, I was just taking a closer look at some of seaicesailor's floes ... note the flanking ambiguous areas of gray which could be new thin ice or older ice now awash in water. In addition to AndreasT's floes breaking along previous lines of refreezing, there are also floes fragmenting along unmotivated lines. On the other hand, the very largest floe, for which we have numerous posts, is a patchwork of older joins but is yet to do any fracturing. It originated back at Prince Patrick whereas the floe above split off by Banks.
