Yesterday, The Cheefio mentioned “During the times I was looking at GIStemp, I’d noticed that GHCN had reduced the high altitude coverage. Thermometers had fled the mountains for lower elevations.”
I’ve been using the Berkley Earth dataset, quality controlled. (not that I trust it for reasons demonstrated here) .
So I thought I would take a quick and dirty snapshot of the BEST data elevation. I looked all stations that had an elevation and had 12 months of data at the decadal rollover (1900, 1910 … 2010).
It looks like the Cheefio was right, with the peak year being near 1940 and then dropping for the next 60 years . (Of course the Elevation may have peaked slightly higher before or after 1940 … I didn’t do every year).
According to a lapse rate calculator I found online, a 46m drop would raise temperature by .45C from 1940 to 2000. I’m not quite sure what to make of the big drop in stations in 2010 and subsequent rise in elevation. The number drops back to 423m in 2010 if you change the criteria to any data in 2010. I must assume many of the stations were incomplete for 2010.