The invaluable Arctic Sea Ice Blog reports:
The PIOMAS graphs at the Polar Science Center of the Applied Physics Laboratory at the University of Washington have been updated. I’d like to start by showing Larry Hamilton’s excellent graph that gives the best perspective:
It’s already below last year’s very low low. In other words, a new record minimum volume.
Here is the current volume as modeled by the folks from the APL/PSC:
And the volume anomaly:
Let me stress that these volume numbers aren’t observed data, but are calculated using the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS, Zhang and Rothrock, 2003). The real numbers probably aren’t off by much, and I base this on some snippets of information like the ice thicknessmeasured at the North Pole by the Polarstern crew and buoy information, but we can’t know for sure until the CryoSat-2 team starts churning out some well-calibrated numbers and ice thickness maps.
Most recent northern sea ice NSIDC ice extent below. As you can see, we have most likely not hit the bottom yet. Stay tuned.
Are there any estimates for before 1979? I guess no direct measurements exist?
Would it be safe to say that only a 1/3 (possibly less) of the Arctic ocean volume remains?
I should rephrase my second question:
Would it be safe to say that the remaining Arctic ice volume is only 1/3 of what it was 30 years ago?