Validation of FORMOSAT-7/COSMIC2 IVM ion density and TGRS orbit electron density

Chou, Min‐Yang; Braun, John; Wu, Qian; Heelis, R. A.; Zakharenkova, Irina; Cherniak, Iurii; Pedatella, Nicholas; Stoneback, R.

doi:10.3319/tao.2021.06.22.01

Cited by 9 publications

(3 citation statements)

References 35 publications

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“…In this paper we use the F7/C2 IVM Level 2 (ivmLv2) les. The ion density by F7/C2 IVM broadly agrees with orbit electron density by the Tri-GNSS radio occultation (RO) System (TGRS) (Chou et al, 2021, Chen et al, 2021. The IVM provides three-dimensional ion drift velocity for magnetic coordinates.…”

Section: Instrumentssupporting

confidence: 53%

Giant ionospheric density hole near the 2022 Hunga-Tonga volcanic eruption: Multi-point satellite observations

Choi

Lin

Rajesh

et al. 2023

Preprint

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A giant ionospheric hole was simultaneously detected in the in-situ measurements of FORMOSAT-7/COSMIC-2 (F7/C2), Ionospheric Connection Explorer (ICON), Swarm missions, and ground-based total electron content (TEC) by global navigation satellite system receivers, and F7/C2 Global Ionosphere Specification (GIS) data near Tonga, following the explosive volcano eruption on 15 January 2022. The TEC maps displayed the huge depletions that developed near Tonga after the eruption and gradually evolved. The ICON IVM, F7/C2 IVM and Swarm-LP detected large depletions not only near Tonga but also in the EIA trough region. The GIS observations clearly show the ionospheric hole that extends spatially near Tonga, especially strongly south/southward. The simultaneous observations showed that the ionosphere hole near Tonga combined with the EIA trough and finally evolved into a giant ionosphere hole around 07 UT. The ionospheric hole, which occurred at 05 UT near Tonga, extended over a wide area of 160°-200°E and 25°S-20°N and lasted for about 11 hours. The F7/C2 and ICON satellites overpasses showed large ion density depletions by the hole at orbit altitudes, accompanied by enhancements in ion temperature and field-aligned and vertical ion drift. Such a long-lasting giant ionospheric hole by a seismic event has not been reported earlier, creating a unique ionospheric environment near Tonga after the eruption. The strong successive impulses by multiple volcano eruptions, together with O/N2 decrease in the summer hemisphere, interhemispheric wind, and water vapor injection into high altitudes apparently yielded such a giant ionospheric hole, 4 ~ 6 times larger than that observed during the Tohoku earthquake.

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Section: Instrumentssupporting

confidence: 53%

Giant ionospheric density hole near the 2022 Hunga-Tonga volcanic eruption: Multi-point satellite observations

Choi

Lin

Rajesh

et al. 2023

Preprint

View full text Add to dashboard Cite

show abstract

“…In this paper we use the F7/C2 IVM Level 2 (ivmLv2) files. The ion density by F7/C2 IVM broadly agrees with orbit electron density by the Tri-GNSS radio occultation (RO) System (TGRS) (Chou et al 2021;Chen et al 2021). The IVM provides three-dimensional ion drift velocity for magnetic coordinates.…”

Section: Instrumentssupporting

confidence: 53%

Giant ionospheric density hole near the 2022 Hunga-Tonga volcanic eruption: multi-point satellite observations

Choi,

Lin,

Rajesh

et al. 2023

Earth Planets Space

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A giant ionospheric hole was simultaneously detected in the in situ measurements of FORMOSAT-7/COSMIC-2 (F7/C2), Ionospheric Connection Explorer (ICON), Swarm missions, and ground-based total electron content (TEC) by global navigation satellite system receivers, and F7/C2 Global Ionosphere Specification (GIS) data near Tonga, following the explosive volcano eruption on 15 January 2022. The TEC maps displayed the huge depletions that developed near Tonga after the eruption and gradually evolved. The ICON IVM, F7/C2 IVM and Swarm-LP detected large depletions not only near Tonga, but also in the EIA trough region. The GIS observations clearly show the ionospheric hole that extends spatially near Tonga, especially strongly south/southward. The simultaneous observations showed that the ionosphere hole near Tonga combined with the EIA trough and finally evolved into a giant ionosphere hole around 07 UT. The ionospheric hole, which occurred at 05 UT near Tonga, extended over a wide area of 160°-200°E and 25°S-20°N and lasted for about 11 h. The F7/C2 and ICON satellites overpasses showed large ion density depletions by the hole at orbit altitudes, accompanied by enhancements in ion temperature and field-aligned and perpendicular ion drift. Such a long-lasting giant ionospheric hole by a seismic event has not been reported earlier, creating a unique ionospheric environment near Tonga after the eruption. The strong successive impulses by multiple volcano eruptions, together with O/N2 decrease in the summer hemisphere, interhemispheric wind, and water vapor injection into high altitudes apparently yielded such a giant ionospheric hole, 4–6 times larger than that observed during the Tohoku earthquake. Graphical Abstract

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“…Note that the low orbit coefficients for FM5 and FM6 are the average results of FM1 to FM4. The correlation coefficients between the two data sets are as high as 0.99, which is higher than those of between the IVM and inverted F7/C2 electron density profiles, which are about 0.95 (Chou et al., 2021). That is understandable as the comparison with inverted electron density profiles include spatial and temporal variations as well as the breakdown of the horizontal homogeneity assumption in the inversion of the electron profiles (e.g., Chou et al., 2017).…”

Section: Ivm and Tgrs Density Comparisonmentioning

confidence: 99%

Comparisons of Ion Density From IVM With the GNSS Differential TEC‐Derived Electron Density on the FORMOSAT‐7/COSMIC‐2 Mission

Pedatella

Braun

et al. 2022

JGR Space Physics

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We report on a new method to derive the on‐orbit electron density using the Tri Global Navigation Satellite System (GNSS) Radio‐occultation System (Tri‐GNSS Radio occultation System (TGRS)) differential total electron content data and compare it to the Constellation Observing System for Meteorology Ionosphere and Climate‐2 Ion Velocity Meter (IVM) ion density data. We found that the IVM ion density is about 8%–15% lower than the TGRS derived density at the insertion orbit (∼710 km) and 5% higher at the mission operation orbit (∼540 km) for reasons that are currently unknown. Using a linear coefficient, we scaled the IVM data to remove the offset between TGRS‐derived electron density and the IVM ion density for the two orbital heights. We believe the scaled IVM densities eliminate any inter‐spacecraft discrepancy, making the IVM data suitable for use in high precision multi‐satellite scientific investigations of longitudinal and local time variations of non‐migrating tides, planetary waves and space weather operational applications.

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Validation of FORMOSAT-7/COSMIC2 IVM ion density and TGRS orbit electron density

Abstract: The comparison between the TGRS and IVM density observations show a good agreement.2. The morphologies of the topside ionosphere in TGRS and IVM are nearly identical.3. Relative errors between the TGRS and IVM density are evaluated with OSSEs.

Cited by 9 publications

References 35 publications

Giant ionospheric density hole near the 2022 Hunga-Tonga volcanic eruption: Multi-point satellite observations

Giant ionospheric density hole near the 2022 Hunga-Tonga volcanic eruption: Multi-point satellite observations

Giant ionospheric density hole near the 2022 Hunga-Tonga volcanic eruption: multi-point satellite observations

Comparisons of Ion Density From IVM With the GNSS Differential TEC‐Derived Electron Density on the FORMOSAT‐7/COSMIC‐2 Mission

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