An Intercomparison of VLF and Sounding Rocket Techniques for Measuring the Daytime D Region Ionosphere: Theoretical Implications

D.E. Siskind, K.A. Zawdie, Fabrizio Sassi, D. Drob, Martin Friedrich

Research output: Contribution to journalArticleResearchpeer-review

Abstract

We compare the two approaches that have been used to measure the lowermost ionosphere,
the measurement of the propagation of very low frequency (VLF) radio waves and the in situ sampling
by sounding rockets. We focus on the altitude, latitude, and zenith angle variation of the electron density
profiles inferred from these two observational techniques as compared with a theoretical photochemical
model. Our results show that below 68–70 km, the VLF data and the model agree better with each other
than with the sounding rocket profile. At the lowest altitudes, near 60 km, both the VLF data and the model
show a greater electron density at higher latitudes, consistent with a cosmic ray flux that increases with
latitude, whereas the limited rocket data show a maximum at the tropics. Above 68–70 km, the VLF data and
the sounding rockets agree better and at tropical latitudes, the model fails to reproduce the observations.
Specifically, the calculated electron density is lower than the data by up to a factor of 2. Possible reasons
for the model deficit include underestimates of the solar Lyman alpha flux, the solar X-ray flux and the
mesospheric nitric oxide density. Once these three factors are mitigated, the model is in agreement with the
observations between 60 and 80 km.
Original languageEnglish
Pages (from-to)8688-8697
Number of pages10
JournalJournal of Geophysical Research / Space physics
Volume123
Issue number10
DOIs
Publication statusPublished - 2018

Fingerprint

D region
Sounding rockets
sounding rockets
very low frequencies
Ionosphere
daytime
ionospheres
ionosphere
electrons
Fluxes
Carrier concentration
radio waves
electron density
Tropics
Radio waves
Cosmic rays
low altitude
zenith
nitric oxide
Rockets

Keywords

    Cite this

    An Intercomparison of VLF and Sounding Rocket Techniques for Measuring the Daytime D Region Ionosphere: Theoretical Implications. / Siskind, D.E.; Zawdie, K.A.; Sassi, Fabrizio; Drob, D.; Friedrich, Martin.

    In: Journal of Geophysical Research / Space physics, Vol. 123, No. 10, 2018, p. 8688-8697.

    Research output: Contribution to journalArticleResearchpeer-review

    @article{82f9fa62261645468e0b4f6125e18835,
    title = "An Intercomparison of VLF and Sounding Rocket Techniques for Measuring the Daytime D Region Ionosphere: Theoretical Implications",
    abstract = "We compare the two approaches that have been used to measure the lowermost ionosphere,the measurement of the propagation of very low frequency (VLF) radio waves and the in situ samplingby sounding rockets. We focus on the altitude, latitude, and zenith angle variation of the electron densityprofiles inferred from these two observational techniques as compared with a theoretical photochemicalmodel. Our results show that below 68–70 km, the VLF data and the model agree better with each otherthan with the sounding rocket profile. At the lowest altitudes, near 60 km, both the VLF data and the modelshow a greater electron density at higher latitudes, consistent with a cosmic ray flux that increases withlatitude, whereas the limited rocket data show a maximum at the tropics. Above 68–70 km, the VLF data andthe sounding rockets agree better and at tropical latitudes, the model fails to reproduce the observations.Specifically, the calculated electron density is lower than the data by up to a factor of 2. Possible reasonsfor the model deficit include underestimates of the solar Lyman alpha flux, the solar X-ray flux and themesospheric nitric oxide density. Once these three factors are mitigated, the model is in agreement with theobservations between 60 and 80 km.",
    keywords = "ionosphere atmosphere",
    author = "D.E. Siskind and K.A. Zawdie and Fabrizio Sassi and D. Drob and Martin Friedrich",
    year = "2018",
    doi = "10.1029/2018JA025807",
    language = "English",
    volume = "123",
    pages = "8688--8697",
    journal = "Journal of Geophysical Research / Space physics",
    issn = "0148-0227",
    publisher = "Wiley-Blackwell",
    number = "10",

    }

    TY - JOUR

    T1 - An Intercomparison of VLF and Sounding Rocket Techniques for Measuring the Daytime D Region Ionosphere: Theoretical Implications

    AU - Siskind, D.E.

    AU - Zawdie, K.A.

    AU - Sassi, Fabrizio

    AU - Drob, D.

    AU - Friedrich, Martin

    PY - 2018

    Y1 - 2018

    N2 - We compare the two approaches that have been used to measure the lowermost ionosphere,the measurement of the propagation of very low frequency (VLF) radio waves and the in situ samplingby sounding rockets. We focus on the altitude, latitude, and zenith angle variation of the electron densityprofiles inferred from these two observational techniques as compared with a theoretical photochemicalmodel. Our results show that below 68–70 km, the VLF data and the model agree better with each otherthan with the sounding rocket profile. At the lowest altitudes, near 60 km, both the VLF data and the modelshow a greater electron density at higher latitudes, consistent with a cosmic ray flux that increases withlatitude, whereas the limited rocket data show a maximum at the tropics. Above 68–70 km, the VLF data andthe sounding rockets agree better and at tropical latitudes, the model fails to reproduce the observations.Specifically, the calculated electron density is lower than the data by up to a factor of 2. Possible reasonsfor the model deficit include underestimates of the solar Lyman alpha flux, the solar X-ray flux and themesospheric nitric oxide density. Once these three factors are mitigated, the model is in agreement with theobservations between 60 and 80 km.

    AB - We compare the two approaches that have been used to measure the lowermost ionosphere,the measurement of the propagation of very low frequency (VLF) radio waves and the in situ samplingby sounding rockets. We focus on the altitude, latitude, and zenith angle variation of the electron densityprofiles inferred from these two observational techniques as compared with a theoretical photochemicalmodel. Our results show that below 68–70 km, the VLF data and the model agree better with each otherthan with the sounding rocket profile. At the lowest altitudes, near 60 km, both the VLF data and the modelshow a greater electron density at higher latitudes, consistent with a cosmic ray flux that increases withlatitude, whereas the limited rocket data show a maximum at the tropics. Above 68–70 km, the VLF data andthe sounding rockets agree better and at tropical latitudes, the model fails to reproduce the observations.Specifically, the calculated electron density is lower than the data by up to a factor of 2. Possible reasonsfor the model deficit include underestimates of the solar Lyman alpha flux, the solar X-ray flux and themesospheric nitric oxide density. Once these three factors are mitigated, the model is in agreement with theobservations between 60 and 80 km.

    KW - ionosphere atmosphere

    U2 - 10.1029/2018JA025807

    DO - 10.1029/2018JA025807

    M3 - Article

    VL - 123

    SP - 8688

    EP - 8697

    JO - Journal of Geophysical Research / Space physics

    JF - Journal of Geophysical Research / Space physics

    SN - 0148-0227

    IS - 10

    ER -