Proposition 06: Probably False

A fairly simple check to see compare two years’ annual mean temperatures:

rmw42@pandora:~/NOAA$ cat Averages.txt | ./compareyears 1934 1998
12 stations had 1934 warmer than 1998
3 stations did not have 1934 warmer than 1998
15139 stations rejected for having insufficient data

As expected, 1934 is warmer, but there aren’t many stations that far back in the daily data – the daily records only start in 1929. This would need to be confirmed against the raw monthly GHCN figures, which are more complete for the ’30s.

The deltas are:

1.7F, 0.3F, 1.2F, 0.3F, 0.0F, -0.8F, 3.4F, -0.8F, -0.4F, 1.5F, 1.7F, 3.6F, 3.1F, 8.5F, 1.7F

These give a mean difference of +1.66F, median of +1.49F, and quartiles of +0.04F and +3.06F.

0.01C is 0.018F, which is less than the lower quartile, so at least 75% of the results (actually 80%) are greater than the claimed difference. 15 samples is about the minimum required to assume that a Gaussian approximation is valid, and these results strongly suggests that the claim is false, but more data would be helpful.

Provisional result: 1934 was warmer than 1998 by 0.8-0.9 degrees Celsius.

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