Single‐Column Emulation of Reanalysis of the Northeast Pacific Marine Boundary Layer

• Published in: Geophysical research letters Vol. 46; no. 16; pp. 10053 - 10060
• Main Authors: McGibbon, J., Bretherton, C. S.
• Format: Journal Article
• Language: English
• Published: Washington John Wiley & Sons, Inc 28.08.2019; American Geophysical Union (AGU)
• Subjects: Artificial neural networks; boundary layer; Boundary layer structure; Boundary layer transition; Boundary layers; Climate variability; Climatology; Cloud properties; Clouds; Computer simulation; Cumulus clouds; emulation; Heating; machine learning; Mathematical models; neural network; Neural networks; Profiles; Properties; Radiative heating; reanalysis; Stratocumulus clouds; Weather forecasting
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2019GL083646

An artificial neural network is trained to reproduce thermodynamic tendencies and boundary layer properties from European Center for Medium‐Range Weather Forecasts Reanalysis 5th Generation high resolution realization reanalysis data over the summertime northeast Pacific stratocumulus to trade cumulus transition region. The network is trained prognostically using 7‐day forecasts rather than using diagnosed instantaneous tendencies alone. The resulting model, Machine‐Assisted Reanalysis Boundary Layer Emulation, skillfully reproduces the boundary layer structure and cloud properties of the reanalysis data in 7‐day single‐column prognostic simulations over withheld testing periods. Radiative heating profiles are well simulated, and the mean climatology and variability of the stratocumulus to cumulus transition are accurately reproduced. Machine‐Assisted Reanalysis Boundary Layer Emulation more closely tracks the reanalysis than does a comparable configuration of the underlying forecast model. Key Points A new machine learning boundary layer parameterization, MARBLE, is developed from ERA5 reanalysis data for the summertime northeast Pacific Used in a single‐column model, MARBLE reproduces ERA5 thermodynamic structure and cloud properties over 7‐day simulation periods MARBLE reproduces the regional climatology of the stratocumulus to cumulus transition