Gravity wave spectra, directions and wave interactions: Global MLT-MFR network
Bibliographic record
Abstract
Observations of winds and gravity waves (GW) by MF radars from the Arctic to the Equator are used to provide frequency spectra and spectral variances of horizontal motions, and information on the predominant azimuthal directions of propagation for the waves. The years used are mainly 1993/4; the height layer 76–88 km; and the GW bands 10 100 min. and 1–6 hrs. The high/mid-latitude locations of Tromsø, Saskatoon, London/Urbana, Yamagawa, generally demonstrate similar behaviour: the monthly spectra have slopes near −5/3 in winter months, but smaller (absolute) slopes at higher frequencies (<2 hrs.) in summer. Corresponding to this, the spectral densities (10–100 min.) are larger for conditions of higher mean background windspeed—this is related by means of a new correlation-vector technique to GW propagating anti-parallel to the mean zonal winds, and the closure of the solstitial mesospheric jets. Also consistent with this, the sizes and orientations of perturbation ovals (fitted to the wind variations), demonstrate strong semi-annual-oscillations (SAO), and generally similar monthly and latitudinal directions. This suggests strong control, especially of the high-frequency GW band, by the dominant zonal wind-structures of the mesosphere. In contrast the low-latitude locations of Hawaii and Christmas Island demonstrate uniquely different behaviours, with indications of significant inter-annual variability. The frequency spectra for all months tend to have smaller slopes at higher frequencies. Also the dependence of spectral density in both GW bands, upon background wind speed, is negative rather than positive, and is shown to be generally consistent with GW propagating parallel to the mean-global winds. This is consistent with weaker vertical shears in the zonal winds (76–88 km), and lower GW momentum depositions. The perturbation ovals reveal much weaker SAO, and more variable orientations, consistent with more dependency upon GW sources, and less control by the mean winds of the mesosphere.
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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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.004 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 0.003 |
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".