Bibliography

Longitudinal Variation of Postsunset Plasma Depletions From the Global-Scale Observations of the Limb and Disk (GOLD) Mission

The Global-scale Observations of the Limb and Disk (GOLD) mission, launched in 2018, aims to investigate the low latitude ionosphere from a geostationary orbit at 47.5°W. It uses two identical spectrometers measuring the wavelength range from 134.0 to 163.0 nm. The configuration of the Earth s magnetic field shows that the largest offset between geographic and geomagnetic equators occurs in the longitude sectors sampled by GOLD. In an attempt to investigate the longitude dependence of the occurrence rate and time of onset of plasma bubbles, or plasma depletions, GOLD data were separated in three sectors: 65°-55°W, 50°-40°W, and 10°W–0°. Observations of the nighttime emissions in 135.6 nm on November 2018 and March 2019 show plasma depletions occurring very frequently at these longitudes. The growth rate of the Rayleigh-Taylor instability was computed at these longitudes under similar low solar activity conditions, assuming an empirical model of upward plasma drifts. The time and value of the maximum growth rates obtained cannot always explain the observations. On average, the observed occurrence rate of plasma depletions is high, with a maximum of 73\% (observed during November 2018 at ∼45°W). Most of the depletions observed in November at 45°W and 60°W occur within 1 h after sunset. When compared with the November 2018 observations, depletions in March 2019 occur at later times.

Martinis, C.; Daniell, R.; Eastes, R.; Norrell, J.; Smith, J.; Klenzing, J.; Solomon, S.; Burns, A.;

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

YEAR: 2021     DOI: 10.1029/2020JA028510

F region; longitude variability; plasma bubbles; Plasma depletions; upward drifts

Spatial and temporal ion drift variability in the high -latitude F region during southward IMF

The purpose of the following research is to investigate the role and contribution of variability or structure in the ion drift to the overall Joule heating rate during times of southward interplanetary magnetic field (IMF). This investigation is limited to southward IMF because the convection patterns are generally more stable and reproducible than those seen for a northward IMF. This allows us to organize the data according to features of the convection pattern and thus produce results that can be used in model simulations of the ionosphere-thermosphere. The contribution of variability or structure in the ion drift to the overall Joule heating is organized into two parts. The first part focuses on the characteristic spatial structure in the ion drift in the F-region ionosphere and how it relates to the bulk ion flow, the large-scale spatial gradient in the bulk ion flow, and the ion temperature. We consider separately the polar cap and auroral zone during the summer and the winter at dawn and dusk during times of steady southward IMF. The second part of this investigation examines the spatial and temporal variability in the ion drift and its contribution to the total Joule heating rate in the F-region ionosphere in the summer and the winter at all magnetic local times (MLT) that are sampled by our data set. This second investigation includes more data than the first investigation by relaxing the stability conditions for southward IMF as well as allowing weaker southward IMF. These topics are investigated utilizing data from the Dynamics Explorer 2 (DE-2) satellite.

Johnson, Eric;

Published by: ProQuest Dissertations and Theses      Published on:

YEAR: 2005     DOI:

Pure sciences; F region; High-latitude; interplanetary magnetic field; Ion drift; atmosphere; 0725:Atmospheric sciences