Several models for estimating sporadic-E intensity from Global Navigation
Satellite System (GNSS) radio occultation (RO) observation have previously
been developed using a single perturbation or intensity parameter, such as
phase-based total electron content (TEC) or the amplitude-based S4 index.
Here, we outline two new models that use a combination of phase and
amplitude parameters for the L1 and L2 signals. These models show a significant
improvement over the baseline models used for comparison. Furthermore,
the GNSS-RO parameters are compared with several different ionosonde
intensity parameters including the direct foEs and fbEs measurements along
with the metallic-ion based foμEs and fbμEs parameters which account for
the background E-region density. Interestingly, the phase-based σϕ scintillation
index shows the strongest correlation to foEs and fbEs while amplitude-based S4
shows the strongest correlation to foμEs and fbμEs. While the metallic-ion based
foμEs and fbμEs parameters are physically ideal for GNSS-RO observations,
we show difficulties in practical implementation due to the reliance on a
background E-region density estimate using a model such as the International
Reference Ionosphere (IRI). Ultimately, we provide two improved sporadic-E
intensity models that can be used for future GNSS-RO based studies along with
a recommendation to compare against the ionosonde-based foEs parameter.
Improved models for estimating sporadic-E intensity from GNSS radio occultation measurements
Emmons, D.J., D.L. Wu, N. Swarnalingam, A.F. Ali, J.A. Ellis, K.E. Fitch, and K.S. Obenberger (2024), Improved models for estimating sporadic-E intensity from GNSS radio occultation measurements, Frontiers in Astronomy and Space Sciences, doi:10.3389/fspas.2023.1327979.
Abstract
PDF of Publication
Download from publisher's website
Research Program
Climate Variability and Change Program
Mission
GNSS
Funding Sources
CSDA
Disclaimer: This material is being kept online for historical purposes. Though accurate at the time of publication, it is no longer being updated. The page may contain broken links or outdated information, and parts may not function in current web browsers. Visit https://espo.nasa.gov for information about our current projects.