Register entry: docs/studio/OPEN_QUESTIONS.md → SCIENCE-6. Raised by task 0.5.
The question. What is the galactic-cosmic-ray ion-pair production rate as a function of altitude, latitude and solar-cycle phase?
Where it stands today. ion_pair_rate is a bare 30.0 cm⁻³ s⁻¹ in the paper ensemble (run_ensemble.py:102), documented in TABLE_microphysics_parameters.md as "galactic cosmic rays at ~20 km" with no citation. The model's own default is 0.0, which disables ion-induced nucleation entirely (coupled/coupled_scenario.py:117). So the two available values are an uncited constant and a value that switches off a physical process.
Why it matters. It feeds the ion-induced channels of Dunne et al. (2016) nucleation, and nucleation is the most sensitive part of this system — the ensemble varies the nucleation rate scale over four orders of magnitude precisely because of that. GCR ionisation varies by roughly a factor of two between solar maximum and minimum, and strongly with latitude and altitude (geomagnetic cutoff rigidity). A single number is wrong nearly everywhere except where it was read off.
What 0.5 does in the meantime. studio/science/gcr.py exposes PAPER_ENSEMBLE_ION_PAIR_RATE = 30.0 as a documented constant with its source, and ion_pair_production_rate(altitude_km, latitude_deg, solar_cycle_phase) raises NotImplementedError naming this issue. It does not return a plausible-looking interpolation of an uncited number (ADR-005).
Done when: either a citable parameterisation is agreed (e.g. a published ionisation-rate model or tabulated CRII data) and implemented with its reference, or the decision is recorded that the fixed ensemble value stands, with the constant's provenance stated and the sensitivity to it quantified.
Register entry:
docs/studio/OPEN_QUESTIONS.md→ SCIENCE-6. Raised by task 0.5.The question. What is the galactic-cosmic-ray ion-pair production rate as a function of altitude, latitude and solar-cycle phase?
Where it stands today.
ion_pair_rateis a bare30.0cm⁻³ s⁻¹ in the paper ensemble (run_ensemble.py:102), documented inTABLE_microphysics_parameters.mdas "galactic cosmic rays at ~20 km" with no citation. The model's own default is0.0, which disables ion-induced nucleation entirely (coupled/coupled_scenario.py:117). So the two available values are an uncited constant and a value that switches off a physical process.Why it matters. It feeds the ion-induced channels of Dunne et al. (2016) nucleation, and nucleation is the most sensitive part of this system — the ensemble varies the nucleation rate scale over four orders of magnitude precisely because of that. GCR ionisation varies by roughly a factor of two between solar maximum and minimum, and strongly with latitude and altitude (geomagnetic cutoff rigidity). A single number is wrong nearly everywhere except where it was read off.
What 0.5 does in the meantime.
studio/science/gcr.pyexposesPAPER_ENSEMBLE_ION_PAIR_RATE = 30.0as a documented constant with its source, andion_pair_production_rate(altitude_km, latitude_deg, solar_cycle_phase)raisesNotImplementedErrornaming this issue. It does not return a plausible-looking interpolation of an uncited number (ADR-005).Done when: either a citable parameterisation is agreed (e.g. a published ionisation-rate model or tabulated CRII data) and implemented with its reference, or the decision is recorded that the fixed ensemble value stands, with the constant's provenance stated and the sensitivity to it quantified.