Brad Ferrier Lecture: Past and Recent Developments in Microphysical Modeling

Greg Thompson
  5 Oct, 2pm

Brad Ferrier was a pioneer in developing a two-moment bulk microphysical parameterization for numerical weather prediction, and much of his seminal 1994 paper has been coded into numerous schemes of the past 25 years. Unfortunately, computational resources always forced simplifications of his complex scheme to adapt into the NCEP operational environment. In his own words, this was the infamous "Physics Wheel of Pain." Nevertheless, Brad found ways to incorporate major concepts from his higher-moment scheme into NCEP's Eta and NMM (NAM) models for operations. Today's computers are now permitting his earlier vision to take shape. For example, the Thompson and Eidhammer (2014) aerosol-aware scheme has been run operationally in the RAP/HRRR/RRFS models while the predecessor Thompson et al (2008) scheme is likely to be used in the GFSv17. The most recent developments in these schemes will be shown including: 1) aerosol/cloud/precipitation interactions, 2) highlights from the ICICLE (2019) winter field campaign, and 3) what happens when you perturb the most uncertain parts within a microphysics scheme to produce new outcomes. Finally, the talk will conclude with ideas for future improvements to model clouds and precipitation.