FaradayInternationalReferenceIonosphere is a collection of convenience functions for working with Faraday-International Reference Ionosphere (FIRI) model profiles.

The underlying FIRI-2018 model DATA, HEADER, and ALTITUDE's can be accessed as e.g. FIRI.HEADER. The unit of ALTITUDE is meters and DATA is electrons per cubic meter.

Only the function firi is exported, but also see FIRI.quantile and FIRI.extrapolate.


For shorthand, load this package like julia using FaradayInternationalReferenceIonosphere import FaradayInternationalReferenceIonosphere as FIRIto reference the package asFIRI`.


Friedrich, M., Pock, C., & Torkar, K. (2018). FIRI-2018, an updated empirical model of the lower ionosphere. Journal of Geophysical Research: Space Physics, 123, 6737-6751. doi: 10.1029/2018JA025437

extrapolate([z,] profile, newz)

Return profile, originally defined at sorted altitudes z, exponentially interpolated and extrapolated to altitudes of newz.

If z is not specified, it is assumed that profile is defined at FIRI.ALTITUDE when the package is loaded as import FaradayInternationalReferenceIonosphere as FIRI.

firi(chi, lat; f10_7=(75, 200), month=(1, 12))

Return the average FIRI profile across the model parameters selected by the keyword arguments and interpolated at solar zenith angle chi and latitude lat.

quantile(chi, lat, p; f10_7=(75, 200), month=(1, 12))

Compute the quantile(s) p at each ALTITUDE with data columns selected by keyword arguments and interpolated to solar zenith angle chi and latitude lat.

selectprofiles(chi, lat; f10_7=(75, 200), month=(1, 12))

Return matrix of selected model profiles interpolated at solar zenith angle chi and latitude lat.

No extrapolation is performed for chi greater than 130°. If chi is greater than 130°, it will be substituted by chi = 130.

twoclosest(s, v)

Return: - the two closest values of vector s to v if v is outside of the range of values in s (extrapolating) - or the closest value on each side of v in column s if interpolating - or [v, v] if v is exactly in s.

The two values are sorted.