Data assimilation with the Canadian Middle Atmosphere Model
Bibliographic record
Abstract
A data assimilation scheme has been coupled to the Canadian Middle Atmosphere Model, providing, for the first time, the capability of assimilating data from the ground to the top of the mesosphere (about 95 km). This model is a full general circulation model with on-line fully interactive chemistry involving 127 gas-phase and heterogeneous reactions. Thus, feedback between dynamics, chemistry and radiation occurs in every model time step. In this work, validation of the system for tropospheric and lower stratospheric analyses is undertaken with the standard observation set used in operational weather forecasting. Results are found to agree reasonably well with radiosonde observations and with Met Office (UK) analyses. Although ozone is not assimilated, ozone fields match total column observations well in terms of synoptic patterns. However, due to model biases, total column values are too large at mid-latitudes and too small in the tropics. Since the assimilation scheme was designed for tropospheric weather prediction, its application to a middle atmosphere model can help to identify the challenges of assimilating data from this region of the atmosphere. RESUME [Traduit par la redaction] Un schema d’assimilation des donnees a ete couple au modele canadien de l’atmosphere moyenne, ce qui fournit, pour la premiere fois, la possibilite d’assimiler les donnees depuis le sol jusqu’au sommet de la mesosphere (environ 95 km). Ce modele numerique est un modele de circulation generale complet avec une chimie parfaitement interactive en ligne impliquant 127 reactions en phase gazeuse ou heterogenes. Ainsi, les retroactions entre la dynamique, la chimie et le rayonnement se produisent a chaque pas de temps du modele. Dans ce travail, on assure la validation du systeme pour les analyses dans la troposphere et la basse stratosphere avec l’ensemble d’observations standard utilise en prevision meteorologique operationnelle. On trouve que les resultats s’accordent raisonnablement bien avec les observations par radiosondes et avec les analyses du Met Office (G.-B.). Bien que l’ozone ne soit pas assimile, les champs d’ozone correspondent bien aux observations totales dans la colonne du point de vue des configurations synoptiques. Cependant, a cause des biais du modele, les valeurs totales pour les colonnes sont trop grandes aux latitudes moyennes et trop petites dans les tropiques. Comme le schema d’assimilation a ete concu pour la prediction des conditions meteorologiques, son application a un modele de l’atmosphere moyenne peut aider a cerner les difficultes d’assimilation des donnees de cette region de l’atmosphere. ATMOSPHERE-OCEAN 43 (1) 2005, 77–100 © Canadian Meteorological and Oceanographic Society *Corresponding author’s e-mail: saroja.polavarapu@ec.gc.ca
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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 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".