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Correcting a coarse-grid climate model in multiple climates by machine learning from global 25-km resolution simulations
  • +6
  • Spencer K. Clark,
  • Noah D. Brenowitz,
  • Brian Henn,
  • Anna Kwa,
  • Jeremy McGibbon,
  • W. Andre Perkins,
  • Oliver Watt-Meyer,
  • Christopher S. Bretherton,
  • Lucas M. Harris
Spencer K. Clark
Allen Institute for Artificial Intelligence / NOAA-GFDL

Corresponding Author:[email protected]

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Noah D. Brenowitz
Allen Institute for Artificial Intelligence
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Brian Henn
Allen Institute for Artificial Intelligence
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Anna Kwa
Allen Institute for Artificial Intelligence
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Jeremy McGibbon
Allen Institute for Artificial Intelligence
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W. Andre Perkins
Allen Institute for Artificial Intelligence
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Oliver Watt-Meyer
Allen Institute for Artificial Intelligence
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Christopher S. Bretherton
Allen Institute for Artificial Intelligence
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Lucas M. Harris
NOAA-GFDL
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Abstract

Bretherton et al. (2022, https://doi.org/10.1029/2021MS002794) demonstrated a successful approach for using machine learning (ML) to help a coarse-resolution global atmosphere model with real geography (a ~200 km version of NOAA’s FV3GFS) evolve more like a fine-resolution model. This study extends that work for application in multiple climates and multi-year ML-corrected simulations. Here four fine-resolution (~25 km) two-year reference simulations are run using FV3GFS with climatological sea surface temperatures perturbed uniformly by -4 K, 0 K, +4 K, and +8 K. A dataset of state-dependent corrective tendencies is then derived through nudging the ~200 km model to the coarsened state of the fine-resolution simulations in each climate. Along with the surface radiative fluxes, the nudging tendencies of temperature and specific humidity are machine-learned as functions of the column state. ML predictions for the fluxes and corrective tendencies are applied in 5.25 year ~200 km resolution simulations in each climate, and improve the spatial pattern errors of land precipitation by 17% to 30% and land surface temperature by 20% to 23% across the four climates. The ML has a neutral impact on the pattern error of oceanic precipitation.