Coordinated Observations of Rocket Exhaust Depletion: GOLD, Madrigal TEC, and Multiple Low‐Earth‐Orbit Satellites

Abstract

A plasma density hole was created in the ionosphere by a rocket launch from Cape Canaveral, Florida near local sunset on 30 August 2020, which is called rocket exhaust depletion (RED). The hole persisted for several hours into the night and was observed in total electron content (TEC) maps, the Global‐scale Observations of the Limb and Disk (GOLD) imager, and multiple low‐earth‐orbit satellites. The RED created a nightglow pit in the GOLD 135.6 nm image. Swarm satellites found that the RED exhibited insignificant changes in electron/ion temperature and field‐aligned currents. On the other hand, magnetic field strength was enhanced inside the RED by a few tenths of a nanotesla. Assimilation data products of the Constellation Observing System for Meteorology, Ionosphere, and Climate 2 (COSMIC‐2) mission reveal that ionospheric slab thickness increased at the center of the RED, which is supported by combined analyses of the GOLD and TEC data. The RED did not host conspicuous substructures that are stronger and longer‐lasting than the ambient plasma did.

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

“…Figure 2b and 2e reveals the early stage of the depletion near Tonga after the eruption. The depletion caused by the eruption is almost identical to a rocketinduced ionospheric hole (e.g., Chou et al 2018;Lin et al 2017a, b;Park et al 2022b). Since the ionospheric hole near Tonga appears in the observations even before sunset, it is unlikely to be the depletion signature of the equatorial plasma bubble, which generally occurs after sunset (e.g., Woodman 2009).…”

“…The Tonga volcanic eruption also injected a large amount of water vapor into the thermosphere, affecting the UV emissions observed by DMSP F-16/SSUSI over Tonga (Paxton et al, 2022).This may have a scenario similar to the ionospheric holes resulting from rocket launches (Bernhardt et al 2001;Chou et al 2018;Lin et al 2014;2017a, b;Liu et al 2018;Park et al 2016;2022b), due to the recombination of ionospheric oxygen ions and water molecules in the rocket exhaust, which reduces the oxygen ion and electron densities. The water vapor induced photochemical processes likely resulted in the absorption of the thermospheric emissions at different wavelengths, such as 121.6 nm, 135.6 nm and 130.4 nm (not shown here), causing a decrease in their intensities.…”

Numerical Modeling and GNSS Observations of Ionospheric Depletions Due To a Small‐Lift Launch Vehicle

“…These ions readily undergo neutralization reactions, reducing ionospheric electron densities. Ionospheric depletions following rocket launches have been observed using a variety of methods, including ionosonde soundings (Booker, 1961), Faraday rotation of satellite signals (Mendillo et al., 1975), air glow images (Mendillo & Baumgardner, 1982), incoherent scatter radar measurements (Wand & Mendillo, 1984), Global Navigation Satellite System (GNSS) signal delays (Furuya & Heki, 2008), satellite Langmuir probe measurements (Park et al., 2016), and satellite ultraviolet spectrograph images (Park et al., 2022).…”

“…These ions readily undergo neutralization reactions, reducing ionospheric electron densities. Ionospheric depletions following rocket launches have been observed using a variety of methods, including ionosonde soundings (Booker, 1961), Faraday rotation of satellite signals (Mendillo et al, 1975), air glow images (Mendillo & Baumgardner, 1982), incoherent scatter radar measurements (Wand & Mendillo, 1984), Global Navigation Satellite System (GNSS) signal delays (Furuya & Heki, 2008), satellite Langmuir probe measurements (Park et al, 2016), and satellite ultraviolet spectrograph images (Park et al, 2022).Several approaches to modeling ionospheric depletions due to rocket exhaust have been described in the literature. Bernhardt et al (1975) derived a formula for exhaust concentration considering diffusion in a stationary stratified atmosphere and computed resulting depletions along a flux tube based on production and loss processes.…”

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

“…al., 2001;Chou et al, 2018;Lin et al, 2014;Liu et al, 2018;Park et al, 2016;2022b), due to the recombination of ionospheric oxygen ions and water molecules in the rocket exhaust, which reduces the oxygen ion and electron densities. The Tonga volcanic eruption injected a large amount of water vapor into the mesosphere, affecting the UV emissions observed by DMSP F-16/SSUSI over Tonga(Paxton et al, 2022).…”