CCPP-ize tropopause_find

[jimmielin]

Issue tracking for CCPP porting of tropopause_find from https://github.com/ESCOMP/CAM/blob/cam_development/src/physics/cam/tropopause.F90 into this repository.

[jimmielin]

Metadata standard names unavailable in CPP for use in tropopause_find:

Time quantities

• calday current calendar day (from get_curr_calday()). Proposing name: fractional_calendar_days_on_end_of_current_timestep

Physical quantities

Not in CF:

• tropLev troposphere level (unit: 1). Proposing name: model_level_number_at_tropopause

In CF:

• tropP using CF name tropopause_air_pressure (unit: Pa)
• tropT using CF name tropopause_air_temperature (unit: K)
• tropZ using CF name tropopause_altitude (unit: m)

with modifiers

Several physical quantities with the same name but using different tropopause finding methods are used in old CAM. In order to have History output for all of them, the same quantities have modifiers denoting which method they were obtained with.

• Default: model_level_number_at_tropopause, etc. - default method in CAM, using lapse rate ("TWMO") tropopause backed with climatology
• Only climatological tropopause: model_level_number_at_tropopause_assuming_climatology, etc. Often used in chemistry packages.
• Only cold point tropopause: model_level_number_at_tropopause_assuming_cold_point, etc. is used in PUMAS microphysics for diagnosis of bias. The possible presence of missing values, i.e. tropopause level equal to -1, is intended behavior for this diagnostic.
• Hybridstobie tropopause backed by climatology: model_level_number_at_tropopause_assuming_hybridstobie_and_climatology, etc. is used by chemistry and RRTMG.

hstobie output for chemistry

The hybridstobie option has additional diagnostics used by old CAM. These diagnostics are intended to be time-averaged to create a unit of "fraction of model time".

• hstobie_trop denotes lowest level with stratospheric chemistry. Proposed name: lower_bound_of_model_level_number_for_stratospheric_chemistry
• hstobie_linoz denotes lowest possible Linoz level. Proposed name: lower_bound_of_model_level_number_for_linoz_chemistry
• hstobie_tropop denotes troposphere boundary calculated in chemistry. Proposed name: model_level_number_at_tropopause_for_chemistry.

other output fields

These probably need changing...

• Relative tropopause height. Currently using tropopause_altitude_relative
• Probability distribution of tropopause (for time-averaged tape). Currently using probability_distribution_of_model_level_number_at_tropopause
• Boolean flag for if tropopause is found. Currently using tropopause_found

Namelist quantities / input datasets

• tropopause_climo_file absolute pathname for tropopause climatology dataset. Proposing name: filename_of_tropopause_climatology
• tropp_p_loc climatological tropopause pressures, dimensions (pcols, ntimes=12) (unit: Pa). Proposing name: tropopause_air_pressure_from_climatology
• tropp_days date slices from said climatological file, dimensions (ntimes=12) (unit: 1). Proposing name: tropopause_calendar_days_from_climatology
• Number of months in year, used for tropopause climatology. Proposing name: number_of_months_in_year