G'day Count,
Thank you for the link by the way.
I'm not sure what you meant though. The data analysis at this link still relies on monthly averages from data sets. As best as I can determine the underlying data is still the GHCN II data set for the SAT (but I could be wrong on this - it simply says that the SAT data is a monthly average of about 3,000 stations). What is different is the use of several other data sets, including sea surface temperature.
I'm not at all sure I agree that "estimates", which is a scientific term for a guess, are small in the latter data sets since the actuall method of how they account for urban effect is available presumably only in the full research paper and it is not one I have. I'll have a look at it in a little while however because it is directly in the area that I have the most interest.
Regards
Richard
