Day-to-day variability of ionosphere electron density during solar minimum derived from FORMOSAT-7/COSMIC-2 measurements
Bibliographic record
Abstract
This study examines the day-to-day variability of low-latitude ionosphere using global ionospheric specification (GIS) electron density profiles derived from FOR-MOSAT-7/COSMIC-2 radio occultation measurements during a deep solar minimum period of August 2019 to July 2020.The measurements reveal significant daily variations over dayside low latitudes, yielding about 10 -20% standard deviation in equinoxes, 20 -30% in solstices, reaching 40 -50% in winter.The nighttime deviations could be 30 -60%, being largest in solstices.Day-to-day variations are also observed in the longitudinal wave-4 structures.The period mostly remained geomagnetically quiet except for some moderate disturbances on a few days.Tidal decomposition of the GIS electron density shows that in-situ forced migrating diurnal (DW1) terdiurnal (TW3) oscillations and the background zonal mean yield only ~25% of the daily variations despite accounting for almost 75 -90% of the observed electron density.Thus, forcing from lower atmosphere dominates the contribution (~75%) to the observed daily variations.Only about one third of this lower atmospheric forcing comes from the migrating semidiurnal SW2 and the usually investigated nonmigrating diurnal eastward DE2, DE3, stationary planetary wave SPW3, SPW4, and semidiurnal eastward SE1, and SE2 components.The residual tides other than those mentioned above, including secondary waves through non-linear interactions and other planetary waves, thus significantly influence the day-to-day variations in electron density and modify the longitudinal wave structures.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".