Walsh and Chapman sea ice data

[skierinvermont]

I decided to create a separate thread for this because the question comes up so often.

I am ashamed to admit that when I first started posting here 5 years ago I dismissed this data because other posters argued that 'it looked funny' (too smooth) and so it couldn't be accurate. But a couple years later I actually bothered to read more about it and why the data appeared so smooth. The answer is basically that the data has been intentionally smoothed because there isn't enough data to form year to year estimates, but there is enough data to form fairly accurate 5 or 10 year averages.

Walsh and Chapman 2001: ftp://128.208.240.87...-walsh_2001.pdf

[The_Global_Warmer]

Thanks for the link. There is quite a few datasets there. Even if the data isn't exactly accurate. It's obvious when 2 or more offices with data going back to the 1900s- 1970s you can get an idea that the errors with the year to year data will be larger than the larger means.

This Also would be backed by temp data sets and glaciers.

This also shows the Ice extent, thickness and volume can be much larger with an active sun.