Magnetospheric disturbance induced equatorial plasma bubble development and dynamics: A case study in Brazilian sector
Bibliographic record
Abstract
Equatorial ionospheric plasma bubble irregularity development and dynamics during the major magnetospheric storm of 26 August 1998 are investigated using the data collected by a multistation and multi‐instrument diagnostic network operated at equatorial and low latitude sites in Brazil, and auroral electrojet activity (AU/AL), IMF, and Dst indices. A magnetospheric disturbance onset in the morning of 26 August 1998 was initiated by a solar wind shock and associated IMF Bz polarity reversals and ssc that were soon followed by a succession of substorm‐like auroral electrojet (AE) intensifications and Dst development. An IMF Bz southward turning and associated AE intensifications in the Brazilian dusk sector produced intense prompt penetration eastward electric field that caused large F region vertical drift and consequently the developments of intense postsunset equatorial anomaly and a series of intense plasma bubbles, the latter event lasting the entire night, as observed by digital ionosondes at São Luís (2.33°S, 315.8°E, dip angle: −.5°) and Fortaleza (3.9°S, 321.55°W, dip angle: −9°) and an all‐sky imager, two scanning photometers, and a Digisonde at the low‐latitude site Cachoeira Paulista (22.6°S, 315°E; dip angle: −28°). A notable aspect of the dynamics of the bubbles was their initially very low eastward drift velocity which turned into steadily increasing westward velocity that lasted till early morning hours. The results show for the first time a relationship between the zonal drift velocities of optically observed large‐scale bubbles (tens to hundreds of kilometers) and that of the smaller scale (kilometer sizes) structures as observed by a digital ionosonde. The results point to the dominant role of a disturbance dynamo associated westward thermospheric wind to maintain the plasma irregularity drift increasingly westward going into postmidnight hours. As an important finding, the results further show that significant contribution to the westward plasma bubble irregularity drift, normally attributed to disturbance dynamo effect, could arise from prompt penetration disturbance zonal electric field, in the course of a disturbance sequence lasting several hours. Such effect is attributed to Hall electric field arising from the primary disturbance zonal electric field, under enhanced nighttime ionospheric conductivities produced possibly by storm associated particle precipitation, in the Brazilian longitude sector in agreement with recent evidences [ Abdu et al., 1998b ].
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".