Bibliography

First Results From the Retrieved Column O/N2 Ratio From the Ionospheric Connection Explorer (ICON): Evidence of the Impacts of Nonmigrating Tides

In near-Earth space, variations in thermospheric composition have important implications for thermosphere-ionosphere coupling. The ratio of O to N2 is often measured using far-UV airglow observations. Taking such airglow observations from space, looking below the Earth s limb allows for the total column of O and N2 in the ionosphere to be determined. While these observations have enabled many previous studies, determining the impact of nonmigrating tides on thermospheric composition has proved difficult, owing to a small contamination of the signal by recombination of ionospheric O+. New ICON observations of far-UV are presented here, and their general characteristics are shown. Using these, along with other observations and a global circulation model, we show that during the morning hours and at latitudes away from the peak of the equatorial ionospheric anomaly, the impact of nonmigrating tides on thermospheric composition can be observed. During March–April 2020, the column O/N2 ratio was seen to vary by 3–4\% of the zonal mean. By comparing the amplitude of the variation observed with that in the model, both the utility of these observations and a pathway to enable future studies is shown.

England, Scott; Meier, R.; Frey, Harald; Mende, Stephen; Stephan, Andrew; Krier, Christopher; Cullens, Chihoko; Wu, Yen-Jung; Triplett, Colin; Sirk, Martin; Korpela, Eric; Harding, Brian; Englert, Christoph; Immel, Thomas;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2021     DOI: 10.1029/2021JA029575

airglow; atmospheric composition; Atmospheric tides; thermosphere

Deducing Non-Migrating Diurnal Tides in the Middle Thermosphere With GOLD Observations of the Earth's far Ultraviolet Dayglow From Geostationary Orbit

The global-scale observations of the limb and disk (GOLD) Mission images middle thermosphere temperature and the vertical column density ratio of oxygen to molecular nitrogen (O/N2) using its far ultraviolet imaging spectrographs in geostationary orbit. Since GOLD only measures these quantities during daylight, and only over the ∼140° of longitude visible from geostationary orbit, previously developed tidal analysis techniques cannot be applied to the GOLD data set. This paper presents a novel approach that deduces two specified non-migrating diurnal tides using simultaneous measurements of temperature and O/N2. DE3 (diurnal eastward propagating wave 3) and DE2 (diurnal eastward propagating wave 2) during October 2018 and January 2020 are the focus of this paper. Sensitivity analyses using TIE-GCM simulations reveal that our approach reliably retrieves the true phases, whereas a combination of residual contributions from secondary tides, the restriction in longitude, and random uncertainty can lead to ∼50\% error in the retrieved amplitudes. Application of our approach to GOLD data during these time periods provides the first observations of non-migrating diurnal tides in measurements taken from geostationary orbit. We identify discrepancies between GOLD observations and TIE-GCM modeling. Retrieved tidal amplitudes from GOLD observations exceed their respective TIE-GCM amplitudes by a factor of two in some cases.

Krier, Christopher; England, Scott; Greer, Katelynn; Evans, Scott; Burns, Alan; Eastes, Richard;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2021     DOI: 10.1029/2021JA029563

airglow; composition; temperature; thermosphere; tides

Tidal and Ionospheric Contributions in GUVI O/N2 wave-4 Signals and Implications for F-region Plasma Density Variability

Oberheide, Jens; Krier, Christopher; Gan, Quan; Nischal, Nirmal; Zhang, Yongliang; Chang, Loren;

Published by:       Published on:

YEAR: 2017     DOI: