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Jacchia-Bowman 2008

This is an empirical thermospheric density model based on the Jacchia theory. It was published in:

Bowman, B. R., Tobiska, W. K., Marcos, F. A., Huang, C. Y., Lin, C. S., Burke, W. J (2008). A new empirical thermospheric density model JB2008 using new solar and geomagnetic indices. In the proeceeding of the AIAA/AAS Astrodynamics Specialist Conference, Honolulu, Hawaii.

For more information, visit http://sol.spacenvironment.net/jb2008.

In this package, we can evaluate the model using the following functions:

AtmosphericModels.jb2008(instant::DateTime, ϕ_gd::Number, λ::Number, h::Number[, F10::Number, F10ₐ::Number, S10::Number, S10ₐ::Number, M10::Number, M10ₐ::Number, Y10::Number, Y10ₐ::Number, DstΔTc::Number]) -> JB2008Output{Float64}
AtmosphericModels.jb2008(jd::Number, ϕ_gd::Number, λ::Number, h::Number[, F10::Number, F10ₐ::Number, S10::Number, S10ₐ::Number, M10::Number, M10ₐ::Number, Y10::Number, Y10ₐ::Number, DstΔTc::Number]) -> JB2008Output{Float64}

where:

  • jd::Number: Julian day to compute the model.
  • instant::DateTime: Instant to compute the model represent using DateTime.
  • ϕ_gd: Geodetic latitude [rad].
  • λ: Longitude [rad].
  • h: Altitude [m].
  • F10: 10.7-cm solar flux [sfu] obtained 1 day before jd.
  • F10ₐ: 10.7-cm averaged solar flux using a 81-day window centered on input time obtained 1 day before jd.
  • S10: EUV index (26-34 nm) scaled to F10.7 obtained 1 day before jd.
  • S10ₐ: EUV 81-day averaged centered index obtained 1 day before jd.
  • M10: MG2 index scaled to F10.7 obtained 2 days before jd.
  • M10ₐ: MG2 81-day averaged centered index obtained 2 day before jd.
  • Y10: Solar X-ray & Ly-α index scaled to F10.7 obtained 5 days before jd.
  • Y10ₐ: Solar X-ray & Ly-α 81-day averaged centered index obtained 5 days before jd.
  • DstΔTc: Temperature variation related to the Dst.

If we omit all space indices, the system tries to obtain them automatically for the selected day jd or instant. However, the indices must be already initialized using the function SpaceIndices.init().

These functions return an object of type JB2008Output{Float64} that contains the following fields:

  • total_density::T: Total atmospheric density [1 / m³].
  • temperature::T: Temperature at the selected position [K].
  • exospheric_temperature::T: Exospheric temperature [K].
  • N2_number_density::T: Number density of N₂ [1 / m³].
  • O2_number_density::T: Number density of O₂ [1 / m³].
  • O_number_density::T: Number density of O [1 / m³].
  • Ar_number_density::T: Number density of Ar [1 / m³].
  • He_number_density::T: Number density of He [1 / m³].
  • H_number_density::T: Number density of H [1 / m³].

Examples

julia> AtmosphericModels.jb2008(
           DateTime("2022-06-19T18:35:00"),
           deg2rad(-22),
           deg2rad(-45),
           700e3,
           79,
           73.5,
           55.1,
           53.8,
           78.9,
           73.3,
           80.2,
           71.7,
           50
       )Jacchia-Bowman 2008 Atmospheric Model Result:
      Total density :    5.19343e-15  kg / m³
        Temperature :         826.77  K
   Exospheric Temp. :         819.72  K
  N₂ number density :    2.65437e+07  1 / m³
  O₂ number density :         193998  1 / m³
  O  number density :    7.67489e+10  1 / m³
  Ar number density :        13.3774  1 / m³
  He number density :    4.64209e+11  1 / m³
  H  number density :    4.07234e+10  1 / m³
julia> SpaceIndices.init()
julia> AtmosphericModels.jb2008(DateTime("2022-06-19T18:35:00"), deg2rad(-22), deg2rad(-45), 700e3)Jacchia-Bowman 2008 Atmospheric Model Result:
      Total density :    2.68424e-14  kg / m³
        Temperature :        1092.62  K
   Exospheric Temp. :        1082.63  K
  N₂ number density :    2.34404e+09  1 / m³
  O₂ number density :     3.4325e+07  1 / m³
  O  number density :    8.34197e+11  1 / m³
  Ar number density :        9466.08  1 / m³
  He number density :    6.86234e+11  1 / m³
  H  number density :    5.86519e+09  1 / m³

If we use the automatic space index fetching mechanism, it is possible to obtain the fetched values by turning on the debugging logs according to the Julia documentation:

julia> using Logging
julia> with_logger(ConsoleLogger(stderr, Logging.Debug)) do
           AtmosphericModels.jb2008(DateTime("2022-06-19T18:35:00"), deg2rad(-22), deg2rad(-45), 700e3)
       end┌ Debug: JB2008 - Fetched Space Indices
│   Daily F10.7           : 140.2 sfu
│   81-day averaged F10.7 : 127.25679012345678 sfu
│   Daily S10             : 113.8
│   81-day averaged S10   : 107.2
│   Daily M10             : 164.0
│   81-day averaged M10   : 138.5
│   Daily Y10             : 150.7
│   81-day averaged Y10   : 143.7
│   Exo. temp. variation  : 64.58333330073704
└ @ SatelliteToolboxAtmosphericModels.AtmosphericModels ~/work/SatelliteToolboxAtmosphericModels.jl/SatelliteToolboxAtmosphericModels.jl/src/jb2008/jb2008.jl:84
Jacchia-Bowman 2008 Atmospheric Model Result:
      Total density :    2.68424e-14  kg / m³
        Temperature :        1092.62  K
   Exospheric Temp. :        1082.63  K
  N₂ number density :    2.34404e+09  1 / m³
  O₂ number density :     3.4325e+07  1 / m³
  O  number density :    8.34197e+11  1 / m³
  Ar number density :        9466.08  1 / m³
  He number density :    6.86234e+11  1 / m³
  H  number density :    5.86519e+09  1 / m³