Scenario kind pagesEdit on GitHubSource: docs/kinds/by-kind/space-weather.md

space-weather (scenario kind)

Scenario kind of the engine v0.38.0, family GNSS measurements, positioning and integrity. Advisory: analysis output from a research and engineering tool, not type-approved navigation equipment and not a safety-of-life service. Every label here is the engine's or the verification matrix's; a kind is MODELLED unless the matrix says otherwise (how a label is earned: the README's Evidence section).

What it does#

Space-weather environment model: solar (F10.7/F10.7a) and geomagnetic (Kp, with the definitional Kp↔ap table) activity indices, the Jacchia-1971 exospheric temperature they drive (validated vs published solar-min/mean/max), and the Jacchia-1971 thermospheric neutral density at the diurnal-mean exospheric temperature against the activity-free static profile at a set of altitudes — the solar-cycle density dependence the static atmosphere omits. MODELLED: the density agrees with accelerometer-derived densities (TOLEOS CHAMP and GRACE) within a factor 2 at solar maximum but is about 1.7x too dense in the 2008 solar minimum.

One run of scenarios/space-weather.toml summarises as: space-weather: F10.7=180 F10.7a=165 Kp=4.0 (ap=27) -> T_inf=1047 K; density x1.49 at 300 km (MODELLED)

Inputs#

From the schema (kshana kinds --json):

  • Required fields: none
  • Optional fields: f107, f107a, kp, altitudes_km

The example scenarios/space-weather.toml sets, among others:

Field Value Unit
altitudes_km [300, 400, 500, 600, 800] km
f107 180 sfu
f107a 165 sfu
kind space-weather text
kp 4 1

Run it#

kshana scenarios/space-weather.toml

What it gives#

The scalar results of that run, with the units the engine states:

Result Value Unit
ap 27 2 nT
exospheric_temperature_k 1046.737945 K
f107 180 sfu
f107a 165 sfu
kp 4 1
mean_exospheric_temperature_k 1186.737445 K

Result label (the engine's): MODELLED — solar/geomagnetic indices, Jacchia-71 exospheric temperature and Jacchia-71 static density at the diurnal-mean temperature

The chart the engine writes for scenarios/space-weather.toml, kind space-weather

Evidence#

MODELLED: the verification matrix rows that name this kind.

  • MODELLED Solar/geomagnetic indices (definitional Kp↔ap table), the Jacchia-1971 exospheric temperature, and the Jacchia 1971 thermospheric density (SAO Special Report 332: static diffusion profiles reproducing its Table 7, with the diurnal, geomagne

The rows the run itself exercised, with the oracle the matrix gives each (the public sources are named there):

  • MODELLED Deterministic, scenario-hashed, SBOM + cross-platform golden gates. Oracle (ExternalDataset): SBOM conformance to the official CycloneDX 1.5 JSON Schema (+ valid SPDX identifiers) — an external published standard, zero validation errors over the full dependency graph; the FoM-determinism / byte-reproducibility part remains a pinned self-consistency check, so the row stays MODELLED
  • MODELLED Solar/geomagnetic indices (definitional Kp↔ap table), the Jacchia-1971 exospheric temperature, and the Jacchia 1971 thermospheric density (SAO Special Report 33. Oracle (ExternalDataset): Definitional Kp↔ap table + Jacchia-1971 exospheric-temperature closed form (matched to <1 K vs the published anchors, tests/space_weather_reference.rs); the density is characterised against pymsis NRLMSISE-00 (an independent NRL model): the 800 km solar-cycle swing is 10.4x against NRLMSISE-00 13.6x. 0.30 revision: the calibrated first-order activity factor was replaced by Jacchia 1971 (default scenario density at 40

Limitations#

What the run's own report says is not modelled or not validated:

  • MODELLED — solar/geomagnetic indices, Jacchia-71 exospheric temperature and Jacchia-71 static density at the diurnal-mean temperature (result label)
  • MODELLED: the density agrees with accelerometer-derived densities (TOLEOS CHAMP and GRACE) within a factor 2 at solar maximum but is about 1.7x too dense in the 2008 solar minimum. (kind catalogue (kshana kinds --json))
  • HONEST SCOPE: MODELLED. The Kp<->ap conversion is the definitional IAGA table and the exospheric temperature is validated against published solar-min/mean/max magnitudes, but the density correction is a CALIBRATED FIRST-ORDER scale-height coupling — it captures the right sign, monotonicity and order of magnitude, NOT the absolute accuracy of a data-validated (NRLMSISE-00) atmosphere. Run: kshana scenarios/space-weath (scenario file comment, lines 10 to 15)
  • Reproducibility & software assurance is MODELLED, not validated: a sub-claim is externally checked, but the whole capability composes modelled pieces, so the capability stays Modelled. (verification matrix (docs/MODELLED-RATIONALE.md))
  • Space-weather environment & activity-driven thermospheric density is MODELLED, not validated: a sub-claim is externally checked, but the whole capability composes modelled pieces, so the capability stays Modelled. (verification matrix (docs/MODELLED-RATIONALE.md))

See also#