VENUS WINDS WITH GROUND-BASED DOPPLER VELOCIMETRY AND COMPARISON WITH COORDINATED CLOUD TRACKING METHOD WINDS
Bibliographic record
Abstract
A complete characterization of the venusian superrotation is crucial for understanding its driving mechanisms. In the lower mesosphere (6585 km), visible observations of Doppler shifts in solar Fraunhofer lines have provided the only Doppler wind measurements near the cloud tops in recent years (Widemann et al., 2007, 2008, Machado et al., 2012). The region is important as it constrains the global mesospheric circulation in which zonal winds generally decrease with height while thermospheric subsolar–antisolar (SS-AS) winds increase (Bougher et al., 1997; Lellouch et al., 1997). A renewed interest in measuring Venus’ winds at cloud top level from the ground has emerged in the course of the Venus Express mission. In orbit since 2006, Venus Express characterizes the atmospheric circulation at 70 km through cloud tracking with combined VIRTIS-M and VMC observations. We will present wind results based on observations from 2009 and 2011 obtained with the 3.60 m Canada-France-Hawaii telescope (CFHT) and the Visible Spectrograph ESPaDOnS. We measure the winds using Doppler shifted solar lines and compare with our measurements with VLT/UVES (Machado et al., 2012) and with previous measurements with Venus Express, and Galileo. For the 2011 observations we will present also the results from the synchronized coordinated observations made by the VMC and VIRTIS cameras from the orbiter Venus Express. Since the Venus Express spacecraft operations started in 2006, a continuous effort has been made to coordinate its operations with observations from the ground using various techniques and spectral domains (Lellouch and Witasse, 2008). Both ground-based and Venus Express measurements show considerable day-to-day variability which needs to be carefully assessed. ESPaDOnS and the sequential technique of visible Doppler velocimetry have proven a reliable way to constrain wind gradients in the lower mesosphere and global wind circulation models. Our main purpose is to provide direct wind measurements in the northern and southern hemispheres from visible Fraunhofer lines scattered at Venus’ cloud tops. This will also contribute for cross validation of the cloud tracking method used in many orbiter-based measurements.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.001 |
| 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 teacher head, 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".