by A. May, Mar 15, 2022 in WUWT
In the Great Climate Change Debate between Professor David Karoly and Professor Will Happer, Glenn Tamblyn was called upon to finish the consensus side of the debate after Karoly backed out. The details are described in my latest book. The debate contained an illuminating exchange of opinions on satellite versus surface temperature measurements. This is Glenn Tamblyn’s opinion:
“Stitching together raw data from multiple satellites is very complex. Thus, the satellite datasets are much less accurate than the surface temperature datasets.
Professor Happer’s stronger emphasis on satellite temperature measurements does not agree with the experts on the subject.”
Satellites measure microwave radiation emitted from oxygen atoms in the atmosphere to estimate the “brightness” temperature, which can then be converted to an actual atmospheric temperature. No correlation to any other measurements is required. The measured brightness is compared to the brightness temperature of deep space (-455°F) and a target of known temperature within the satellite to compute the actual temperature in the atmosphere.[1]
Due to interference and clouds, this technique does not work close to the surface, so satellite atmospheric temperatures cannot be directly compared to surface measurements. The satellite measurements are best for measuring air temperatures in the mid-troposphere and the lower stratosphere.
The Hadley Centre has estimated that their best current estimate of global monthly average SST accuracy(sea surface temperature average uncertainty from 2000 to 2021) is about ±0.033°C and David Karoly supplied an estimate of ±0.1°C. This is a bit less accurate than the accuracy Roy Spencer and John Christy estimate for their satellite measurements of ±0.011°C for a monthly average.[1]