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Record W2888225049

Gravity Wave Generation and Momentum Deposition in the Atmosphere

2017· dissertation· en· W2888225049 on OpenAlexaboutno aff
Mahtab Majdzadeh

Bibliographic record

VenueYorkSpace (York University) · 2017
Typedissertation
Languageen
FieldPhysics and Astronomy
TopicPlanetary Science and Exploration
Canadian institutionsnot available
Fundersnot available
KeywordsAtmosphere (unit)Deposition (geology)Momentum (technical analysis)PhysicsEnvironmental scienceAstrobiologyAtmospheric sciencesMeteorologyGeologyBusinessPaleontology
DOInot available

Abstract

fetched live from OpenAlex

The first part of this study investigates gravity wave parameterization in the middle atmosphere, focusing on internal waves with a broad spectrum of phase speeds. A column model based on CIRA wind and temperature profiles is employed to assess the characteristics of the Hines Doppler-Spread (1997) and Warner-McIntyre-Scinocca (2001) nonorographic drag parameterizations for internal gravity waves. The Alexander-Dunkerton (1999) variant of Warner-McIntyre-Scinocca scheme is also briefly considered. 
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\nThis study goes into more detail than previous comparisons by performing a spectral analysis of the momentum deposition and drag, and by examining the ability of each scheme to reproduce saturation. Comparisons with pure critical level filtering are also made, and it is found that Hines DSP mainly constitutes an enhancement to critical level absorption, while the Warner-McIntyre-Scinocca scheme produces substantially different wave drag profiles. We find several undesirable characteristics in the drag produced by the Hines scheme. For typical midlatitude profiles, it produces an abrupt onset of large accelerations that are confined to a relatively narrow layer. It is also unable to reproduce wave spectra consistent with observed saturation at high vertical wavenumbers. 
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\nThe second part of this study investigates the generation mechanisms of the gravity waves over Newfoundland and Labrador (NL). We performed a series of simulations for a selection of the strongest peak events using WRF model to further investigate the characteristics and generation mechanisms of gravity wave peak events over NL. We studied three different peak events, 2003, 2008 and 2014. 
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\nWe showed that gravity wave events in the winter hotspot region over NL can have both topographic and jet streak sources. In the cases we examined, one source of waves was the Torngat range on the northern coast of Labrador. However, the other two wave sources were in fact outside the hotspot region, and a combination of advection and propagation caused those packets to enter the hotspot in the middle atmosphere. We have demonstrated that topographic wave packets, which are normally assumed to remain stationary over the source, can in fact be advected far downstream from the source.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

How this classification was reachedexpand

Full frame distilled prediction

Teacher imitation

Not 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.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.293
Threshold uncertainty score0.555

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

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.

Opus teacher head0.017
GPT teacher head0.203
Teacher spread0.186 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one teacher head, not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designObservational
Domainnot available
GenreEmpirical

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".

Quick stats

Citations1
Published2017
Admission routes1
Has abstractyes

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