Good article:
http://www.smh.com.au/environment/climate-change/remarkable-year-whats-behind-the-record-low-sea-ice-in-antarctica-20161125-gsxo4p.htmlEdit: sorry, I didn't notice that Steven had already linked to this above.
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GIOMAS modelled Antarctic sea ice volume until 2012, as plotted by Wipneus:
https://sites.google.com/site/arctischepinguin/home/giomasSome papers about thickness/volume of Antarctic sea ice:
Thickness distribution of Antarctic sea ice:
http://onlinelibrary.wiley.com/doi/10.1029/2007JC004284/fullA model reconstruction of the Antarctic sea ice thickness and volume changes over
1980–2008 using data assimilation:
http://nora.nerc.ac.uk/501476/1/massonnet_etal_OCMOD13.pdfSatellite observations of Antarctic sea ice thickness and volume:
http://onlinelibrary.wiley.com/doi/10.1029/2012JC008141/fullAntarctic sea-ice freeboard retrieval using CryoSat-2: possibilities, limitations, uncertainties:
http://epic.awi.de/37542/About the consistency between Envisat and CryoSat-2 radar freeboard retrieval over Antarctic sea ice:
http://epic.awi.de/41243/ICESat measurements of sea ice freeboard and estimates of sea ice thickness in the Weddell Sea:
http://onlinelibrary.wiley.com/doi/10.1029/2007JC004284/full--------------------------------------------------------------------------------------------
I think it's also worth remembering that ESMR passive microwave satellite data are available for 1972-1976. For instance:
Maps available here:
http://ntrs.nasa.gov/search.jsp?R=19840002650ESMR extent data from Cavalieri et al. 2003 available here:
ftp://sidads.colorado.edu/pub/DATASETS/nsidc0192_seaice_trends_climo/total-ice-area-extent/esmr-smmr-ssmi-merged/ (these data need a small upward adjustment to match NSIDC Sea Ice Index numbers from 1978:
ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/)
For comparison purposes, this is the latest map from Uni Bremen:
1976 is currently the second lowest year, as we can see at the graph below, that shows some of the lowest years of the 1973-2016 time series (2016 updated until November 28th):
I have also found an interesting paper by Ackley (1981,
http://hydrologie.org/redbooks/a131/iahs_131_0127.pdf) who presents data compiled by Kukla et al. (1977). The graph below shows late November Antarctic sea ice extent from 1967 to 1976. I think this graph is very intereresting because, as far as I know, it is the only contemporary attempt to present a "long" time series. It's also remarkable because it is the only time series that covers the 1972-1973 boundary between visible imagery and passive microwave data:
I have extracted the data from that graph, and compare them against ESMR Cavalieri numbers for 1972-1976. They match very well with November 25th ESMR numbers, so I have been able to plot the graph below. Late November Antarctic sea ice extent from 1967 to 2016:
The current Antarctic sea ice extent is the lowest for late November from 1967 as well.
There is a small downward trend from 1967 to 2016, although taking into account the larger error margins of the 67-72 numbers and the high interannual variability, maybe we should understand that the trend 1967-2016 is basically flat.