CCPP Framework Meeting Minutes 2021 11 18

Agenda

• Transition to capgen.py
• Dictionary of standard names
• CCPP requirements document
• Other business

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Transition to capgen.py

Dictionary of standard names

• Start using dictionary and standard name rules in CCPP Framework?
  • use standard name to determine mass mixing ratio (rule 5) or volume mixing ratio (rule6)?
  • Current Thompson scheme wrapper uses internal conversion to local variables
  • Move towards using rules with interstitial routines to provide conversion
  • Eventually move towards auto-insertion of interstitial routines
  • How to handle arrays of constituents in the meantime?
• Inconsistency of naming mass mixing ratios vs. volume mixing ratios
  • cloud_liquid_water_mixing_ratio_wrt_moist_air but volume_mixing_ratio_of_ch4
  • Why not mixing_ratio_of_cloud_liquid_water_wrt_moist_air or ch4_volume_mixing_ratio?
• Why is standard name dictionary organized by GFS type?
• Is specific humidity the mass mixing ratio of vapor with respect to moist air or with respect to total mass (rule 5)?
• The lengthy discussion about units for dimensionless quantities (all triggered by relative humidity - https://github.com/ESCOMP/CCPPStandardNames/issues/26)

CCPP requirements document

• https://dtcenter.org/community-code/common-community-physics-package-ccpp/requirements
• https://docs.google.com/presentation/d/1ZYnxxKK70tb2muPn5Os7V1Z23Rwj2Q5EcdqzqHx7Kpg/edit#slide=id.g102054263e9_0_21
• Ligia: Recap from yesterdays code-management meeting. Requirements need udpating.
  • Matt asked if requirements necessary, does it serve our needs? Current document is long and complicated.
  • Alternative is to reference current technical documentation
  • Future requirements could be stored in GitHub as issues (or discussions?)
  • Ligia thinks that we have moved past the skeptical phase of the CCPP
  • Proposal to replace requirements document with section of CCPP technical documentation
  • Take proposal back to CCPP Code Management committee

Other business

• Handling constituent information originating from a physics scheme
  • Postponed discussion
• Specifying a data source for an input variable (see #413)
  • Postponed
• Looking into the (distant? may be not so much) future: 3D physics
  • Steve: Is timestep_init and timestep_final good enough?
  • Dom Hannah Barnes mentioned high-res convection (3-10 km) scheme and radiation schemes
  • Great if we could have CCPP participation in physics discussions
• Looking into the very near future: Who will prepare and run the framework meetings in Dom's absence?
  • Dom will participate until Feb 27, 2022, but stop preparing and leading the meeting by the end of 2021