CCPP Framework Meeting Minutes 2021 01 05

Agenda

• capgen.py progress
  • Advection feature (w/ NRL)
  • Organization for code modularity (e.g., diagnostic code)
• Transition to capgen.py
• Other business

capgen.py progress

• Need plan yet how to handle optional arguments (Dom to reach out to developers - EMC, GSL, Robert & Dustin, Phil, NRL)
• DTC needs to develop a mechanism to avoid using the field_table - use an internal field table approach, similar to the internal input file? --> Dom to create issue in UFS
• where to put little helper libraries such as a hash table etc?
  • for now, make a submodule of ccpp-framework
• CCPP error handler (another lightweight module)
  • when switch over from current error handling variables?
  • probably best after the transition to capgen.py
  • possibility for a smooth transition (could use either new error handler or keep using errmsg and errflg in scheme, framework does the rest)

Transition to capgen.py

• Updated DTC timeline and resource chart (https://docs.google.com/spreadsheets/d/1XbSF1ejYcPMrVtZtk1OSiMX-vI5srLkwEUhyAirGr8k/edit?usp=sharing)
• Things that need to happen for transitioning UFS to capgen.py (https://docs.google.com/document/d/1M3mCO3ESR9OJqLyUbQf-ahJtmfmGKilZlWaBTxsfMRk/edit?usp=sharing)
• timestep_init and timestep_final implementation will be merged mid January
• Transition at the end of February
• Dictionary of standard names:
  • https://meet.google.com/linkredirect?authuser=0&dest=https%3A%2F%2Fdocs.google.com%2Fspreadsheets%2Fd%2F1kWDC7_2sagm-PTP_tXaGyI3O3sJFK8FY9FElQbb6V3o%2Fedit%23gid%3D1778121391
  • largely in agreement, a few clarifications and suggestions for abbreviations, what is the default if not explicitly spelled out
  • binary mask versus other types of masks (three categories, ...)
  • flag, option, switch, control, ... --> use flag for boolean true/false, control for integer
  • CCPP error handling variables - better standard names
  • need a convention on how to order the components that make up a standard name: variable name, at xyz, for abc, ...; where does "tendency_of" go?
  • CF does define rules for the order of standard name components
• Is the active attribute implementation in ccpp_prebuild.py a good one, or the implementation in capgen.py? What is the best way forward?
  • current implementation in ccpp_prebuild.py: https://ccpp-techdoc.readthedocs.io/en/latest/

Other business

• Physics interoperability / shared code - example NoahMP
  • error handling
• Suite definition file examples from the UFS: https://github.com/NOAA-EMC/fv3atm/tree/develop/ccpp/suites