Thursday, November 08, 2018

Another failure of peer review, due to corrupt temperature data from a single station | Watts Up With That?

Another failure of peer review, due to corrupt temperature data from a single station | Watts Up With That?
"...Notice anything odd? 
I sure did. 
As many of you know, I’ve spent years looking at weather stations around the world, spotting problems that contribute to temperature bias. 
This one has at least four visible biases that will likely cause it to read warmer than it should, especially in the overnight Tmin temperature.
Here are the issues:
  1. Metal roof is nonstandard. It looks like they used the same sheet roof as the buildings in the background.Stevenson Screens are defined to have a wooden roof, painted white. I would expect this metal roof to bias the Tmax upwards in days with direct sun.
  2. Closer to surface than normal. While I can’t absolutely confirm this with a measurement, it appears the based of the Stevenson screen is about 1 meter from the surface, based on my experience with inspecting weather stations.  The standard is supposed to be a minimum of 1.5 meters. This will bias both the Tmax and Tmin upwards if my observation is correct.
  3. Cattle guard surrounding station. This metal structure will act like a heat sink, biasing the Tmin temperature upwards as it dumps the heat it has absorbed from the sun during the day.
...it is clear to me that combined, these three observed issues at the Rekomitjie Research Station will likely contribute an upward bias effect on temperatures measured by this station.
4. But wait, there’s more..."
Read all!

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