I think you might be interested in my study of Arctic sea ice extent. I put most of it together some time back and have finally managed to revisit it adding some of the things that should have been there first time around. The data sources have not been updated since I wrote it originally.
It now contains calculations of difference between the satellites. Whilst the trend is a little on the high side, probably due to the apparent more rapid decline in the overlapping time frame, it does suggest that all the apparent Arctic sea ice extent decline might be accounted for by measurement drift.
How Fast is Arctic Sea Ice Declining?
by Jonathan Drake
Day after day we are bombarded with images of polar bears on ice bergs and collapses of ice sheet into the ocean with apocalyptic headlines that the Arctic ice will vanish within a few years. It is of particular interest that, according to Dr. Vicky Pope, head of Climate Change at the UK Met Office, “Recent headlines have proclaimed that Arctic summer sea ice has decreased so much in the past few years that it has reached a tipping point and will disappear very quickly. The truth is that there is little evidence to support this. Indeed, the record-breaking losses in the past couple of years could easily be due to natural fluctuations in the weather, with summer sea ice increasing again over the next few years.” Met Office: Stop misleading climate claims
So, on that basis, what is going on? Could there be some kind of misinterpretation of the data? Might someone have made a wild extrapolation? With these questions in mind the Arctic sea ice records are examined to see what, if anything can be learnt.
The two commonly cited measures for sea ice are extent and area. Many people are unaware that there are two different measures, let alone a difference or what it is and so a simplified definition would seem useful. Both are presently derived from satellite and calculated from images. Each pixel of the image is assigned an area.
Download PDF file from Trevoole.co.uk to read FULL report by Jonathan Drake