Experiments / Project 702 / Write ups

WBGT Extrapolation Experiments – Summary

I have been working on the WBGT calculation with some success.


  • Iterative method can be described by a linear function
  • Using this function, WBGT can be calculated directly
  • The calculation is much much faster than iterating (important for Matthias’ volume)
  • The function is suitably accurate ( +/- 0.5 degrees) for over 90 % of the cru database (and 100 % of 2010, 2011 data)
  • The accuracy of the fit depends on the relative values of Ta and Td
  • A simple adjustment factor has been found that improves the fit.

While the fit isn’t perfect, it is potentially a viable alternative to the iterative method. Further experimentation and refinement would be required to prove this claim.



Since this post, we have found that we can use a linear model for WBGT to significantly reduce the number of iterations required to reach an accurate approximation of WBGT. We were able to derive an initial value of WBGT (w`) that was very close to the final value (wf)and then refine w` until it neared the limit of wf. One day I will write this up properly.


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