Formation and Evolution of Low‐Latitude <i>F</i> Region Field‐Aligned Irregularities During the 7–8 September 2017 Storm: Hainan Coherent Scatter Phased Array Radar and Digisonde Observations
Bibliographic record
Abstract
Abstract In this paper, we present a study of the low‐latitude field‐aligned irregularities formation and evolution during the 7–8 September 2017 geomagnetic storm by analyzing data of the very high frequency coherent radar installed at Fuke, Hainan Island of China (19.5°N, 109.1°E; magnetic latitude 9.58°N) and a colocated Digisonde Portable Sounder. The prompt penetration of eastward interplanetary electric field associated with sudden southward turning of the interplanetary magnetic field Bz resulted in large ascent of the F layer, making conducive conditions at the bottomside of the layer for the growth of Rayleigh‐Taylor instability and the development of the plasma irregularities in the postsunset hours. The irregularities persisted into the postmidnight sector when the southward interplanetary magnetic field Bz gradually decreased to the quiet time values. In addition, the base height of F layer at Fuke also showed a large elevation after midnight during two consecutive substorm onsets, suggesting that the substorm‐induced overshielding penetration electric field may take over and modify the ambient zonal electric field in low‐latitude ionosphere and induce the irregularities in the postmidnight sector. Moreover, different from the quiet time eastward movement of the irregularities observed over Fuke, the storm time irregularities displayed no zonal drift at the initial period and subsequently began drifting westward. The reversal of background plasma zonal drift velocity observed by Hainan digisonde characterized the storm time zonal drift pattern of the irregularities.
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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 | 0.000 |
| 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".