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Gaussian process regression-based Bayesian optimisation (G-BO) of model parameters - a WRF model case study of southeast Australia heat extremes
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  • P. Jyoteeshkumar Reddy,
  • Sandeep Chinta,
  • Harish Baki,
  • Richard J. Matear,
  • John Taylor
P. Jyoteeshkumar Reddy
CSIRO Australia

Corresponding Author:[email protected]

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Sandeep Chinta
Massachusetts Institute of Technology
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Harish Baki
Delft University of Technology
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Richard J. Matear
CSIRO Marine and Atmospheric Research
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John Taylor
Australian National University
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Abstract

In Numerical Weather Prediction (NWP) models, such as the Weather Research and Forecasting (WRF) model, parameter uncertainty in physics parameterization schemes significantly impacts model output. Our study adopts a Bayesian probabilistic approach, building on prior research that identified temperature (T) and relative humidity (Rh) as sensitive to three key WRF parameters during southeast Australia’s extreme heat events. Using Gaussian process regression-based Bayesian Optimisation (G-BO), we accurately estimated the optimal distributions for these parameters. Results show that the default values are outside their corresponding optimal distribution bounds for two of the three parameters, suggesting the need to reconsider these default values. Additionally, the robustness of the optimal parameter distributions is validated by their application to an independent extreme heat event, not included in the optimisation process. In this test, the optimised parameters substantially improved the simulation of T and Rh, highlighting their effectiveness in enhancing simulation accuracy during extreme heat conditions.
09 Jul 2024Submitted to ESS Open Archive
15 Jul 2024Published in ESS Open Archive