be cause: can only guestimate area that heads out of the basin but it is a lot
Right. Wind-driven ice motion has been extraordinary this freeze/melt season. By translocating thicker, older ice into zones that will melt out later in the summer, or exporting ice altogether out of the basin via the Fram, Nares and Svalbard-FJL chain plus blocking Kara Sea ice on the import side, wind-driven ice motion may challenge conventional bottom and top melt this year as the leading ice volume loss mechanism.
The first image below shows on mid-basin Atlantic-side feature drift (boundary between old and new ice) over the the last 195 days using twenty-day contours.
A similar area of ice ahead of the front has been (or will be if wind patterns keeps up) irreversibly displaced out of the basin. This area can be measured, not adjusting for compression or extension, by lifting geo-referenced Ascat images onto Google Earth Pro for its ellipsoidal (WGS84) area and length calculations (2nd image shows the 7.109 million sq km polygon of relevant Arctic Ocean.
Wx predictions are the proverbial drunk looking for her car keys under the street lamp because the light is better there -- winds thousands of meters above the ice are easier to predict than the 0m winds, yet only the latter actually move the ice pack (by coupling to pressure ridges and floe edges rather than flat pan).
You can see this on any given day by comparing ice motion vectors observed by OSISAF/NSIDC to winds GFS or ECMWF are showing, before or after reanalysis (3rd image). Surface currents are negligible (or as oceanographer R Woodward notes, induced by ice keels) outside the intake funnels of the Nares and Fram and inconsistent Bering Strait flows to/from the Chukchi. Note the ice pack has a certain amount of mechanical rigidity, leading to cohesive motion despite a heterogeneous stress field.
The Arctic Ocean is seriously 'under-instrumented', meaning models have never had sufficient calibration or feedback guidance. On the rare instances an instrumented ship has been out there in May (eg N-ICE spring 2015), measurements departed markedly even from nearby land stations like Ny-Ă…lesund. However nobody ever fixed a weather model or reanalysis based on a basin instrument account.
Help is in sight (with a 2-3 year delay?): this Sept, AWI's Polarstern will drift for a full year on a thick Siberian-side floe (lol !) to collect "direct in-situ observations of the climate processes that couple the atmosphere, ocean, sea ice, bio-geochemistry and ecosystem ... to enhance understanding of the regional and global consequences of Arctic climate change and sea-ice loss and improve weather and climate predictions.
https://www.mosaic-expedition.orgThis won't be meagre point weather and ice properties because they are going out to a 50 km swath radius on both sides of the drift track. The 4th image shows a hypothetic drift trajectory. They'd have been home early this year whereas in 2017/18 the ship would hardly have moved in the hoped-for direction:
233 days of anti-transpolar drift 2017-2018.mp4
https://forum.arctic-sea-ice.net/index.php/topic,2278.msg155398.html#msg155398The Oden made a remarkable observation of open water at the north pole on 25 Aug 18, photographing a walrus there, messing with a research sled. Ask yourself how much open water there had to be regionally for a walrus to swim to the NP on that date and when it last ate: the water is 4,087 m deep whereas the deepest walrus dive ever recorded is 500m.
This and a few little things like ice thickness went seriously under-reported (except by Jim Hunt and twitter). This has really got to change -- scientists chewing on their cud for years (buffing their journal articles) while leaving everyone else in the dark.
I had an identical experience trying to get even the most mundane CTD casts from the Polarstern when by great good fortune they were able to reach the Weddell Sea during that unprecedented reversal of the Fram in Feb 18 attributed to a sudden stratospheric warming. A cr*ppy article by another research group ensued who also couldn't get the data. Where is the public benefit in hoarding?