Data · dataset · 2026
Formation of the equatorial thermosphere anomaly trough: Local time and solar cycle variations
Listed in National Center for Atmospheric Research
This paper evaluates the formation and behavior of the equatorial thermosphere anomaly (ETA) trough in neutral temperature and mass density using the National Center for Atmospheric Research thermosphere-ionosphere electrodynamics general circulation model under quiet geomagnetic activity and March equinox conditions.
Description
The driving mechanism for the generation of the ETA trough in the model is field-aligned ion drag. In our simulations, during the daytime, field-aligned ion drag on the north-south flanks of the magnetic equator causes a divergence in meridional winds, leading to an upward change in vertical winds, adiabatic cooling, and a reduction in neutral temperature of about 30 K over the magnetic equator near 400 km.
This response closely links ETA behavior to variations in the equatorial ionosphere anomaly (EIA) associated with local time and solar cycle. As the EIA begins to disappear in the evening, the processes in the ETA mechanism recede, causing the ETA trough to subside. The ETA trough is not completely eliminated until about after 23:00 LT.
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In our simulations, the trough becomes more prominent as the solar cycle progresses from low (F10.7=80) to high (F10.7=180), in agreement with observations. The neutral-ion collision frequency (proportional to variations in electron density) controls ETA day-to-night and solar cycle variations, while plasma scale height and gradients in electron number density and plasma temperature produce a secondary structure in ETA local time behavior that varies with solar cycle levels.
Links
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- Publisher page n2t.org/ark:/85065/d77s7pr1 ↗
documentation · download · from data ucar edu
Where it is published
- data.ucar.edu /dataset/formation-of-the-equatorial-thermosphere-anomaly-troug… ↗
National Center for Atmospheric Research dataset page
landing page · from data ucar edu
Catalogue records · 1
- CKAN API data.ucar.edu/api/3/action/package_show?id=e3bb62ff-ca10-40b9-8bc5-7ee0a4555… ↗
metadata API · from data ucar edu
Topics
- From keywords
- Earth & Environmental Science · Ocean & Atmospheric Science
- Inferred from text
- Tropospheric and stratospheric physics 76%
Provenance · 1 source records, 8 field assertions
| Source | Key | Last seen | Raw |
|---|---|---|---|
| National Center for Atmospheric Research | e3bb62ff-ca10-40b9-8bc5-7ee0a4555c98 | 10 d ago | JSON v1 |
| Field | Assertion | Extractor | Evidence |
|---|---|---|---|
| concepts[field].anzsrc:field:370109 | enrichment · data ucar edu | taxonomy-embedding@1.1.0 | title+keywords+description (76%) |
| concepts[field].local:field:earth-environmental | mapping · data ucar edu | connector:data_ucar_edu@1.0.0 | |
| concepts[field].local:field:ocean-atmospheric | mapping · data ucar edu | connector:data_ucar_edu@1.0.0 | |
| created_date | source · data ucar edu | connector:data_ucar_edu@1.0.0 | |
| description | source · data ucar edu | connector:data_ucar_edu@1.0.0 | /notes |
| publication_date | source · data ucar edu | connector:data_ucar_edu@1.0.0 | |
| title | source · data ucar edu | connector:data_ucar_edu@1.0.0 | /title |
| updated_date | source · data ucar edu | connector:data_ucar_edu@1.0.0 |