This time the Sea Ice Volume Series offers an interactive feature to explore sea ice reduction in 2012. Just hover your mouse over the months below to load the indicated map.
PIOMAS shows significant reduction in thickest ice category North of Greenland and the Archipelago in December. An overall thinning compared to December 2011 is also observable, but less surprising, because that's the trend.-> continue reading
A new installment of the sea ice volume/thickness series, this time it's from latest the 2007 IPCC AR4 Report, Working Group I: The Physical Science Basis, chapter 18.104.22.168 Evidence of Changes in Arctic Pack Ice Thickness from Submarine Sonar:
Estimates of thickness change over limited regions are possible when submarine transects are repeated (e.g., Wadhams, 1992). The North Pole is a common waypoint in many submarine cruises and this allowed McLaren et al. (1994) to analyse data from 12 submarine cruises near the pole between 1958 and 1992. They found considerable interannual variability, but no significant trend. Shy and Walsh (1996) examined the same data in relation to ice drift and found that much of the thickness variability was due to the source location and path followed by the ice prior to arrival at the pole.-> continue reading
Since the draft of latest +1000 pages US Climate Assessment completely ignores volume as a dimension of Arctic sea ice - probably assuming constant thickness during satellite era - I'll start here a series of findings to give evidence sea ice volume is not an unknown thing to science.
To be fair, the search term 'sea ice thickness' appears once in Chapter 12, Tribal, Indigenous, and Native Lands and Resources
Scientists across the Arctic have documented regional warming over the past few decades at twice the global rate, and indigenous Arctic communities have been observing the changes in their daily lives. This warming is accompanied by significant reductions in sea ice thickness and extent, increased permafrost thaw, more extreme weather and severe storms, changes in seasonal ice melt/freeze of lakes and rivers, water temperature, flooding patterns, erosion, and snowfall timing and type
Later this spring the series will result in a comment to the draft and hopefully the key message with a projection of an ice free Arctic earliest in the middle of the century got revised.
Here is the first part of the series, a paper presented for discussion earlier this week, written by V. A. Alexeev, V. V. Ivanov, R. Kwok and L. H. Smedsrud and titled: North Atlantic warming and declining volume of arctic sea ice, [full text] The article tries to estimate the eﬀect of the recent North Atlantic warming on the ice melting processes happening at the outlet of the Arctic Ocean near Fram Strait, Svalbard and Franz Joseph Land.-> continue reading