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Record W6983053999

Layer-layer interactions in atmospheric, cryospheric, and stellar dynamics

2023· dissertation· en· W6983053999 on OpenAlexaboutno aff

Bibliographic record

VenueDSpace@MIT (Massachusetts Institute of Technology) · 2023
Typedissertation
Languageen
FieldPsychology
TopicHearing Impairment and Communication
Canadian institutionsnot available
Fundersnot available
KeywordsStratosphereTroposphereTrace gasOzone layerAnticycloneUpwellingSouthern HemisphereNorthern Hemisphere
DOInot available

Abstract

fetched live from OpenAlex

Layer-layer interactions comprise some key scientific unknowns and uncertainties in regional and large-scale planetary climate models. My dissertation studies their behaviour with an aim to develop explanations for and improve representations of observed phenomena. I focus on three different systems: stratosphere-troposphere coupling, ice-sediment mechanics, and turbulence in velocity-layered stellar interiors.
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\nThree distinct manifestations of stratosphere-troposphere coupling are studied in this dissertation. First, evidence suggests that ozone depletion has driven changes in southern hemisphere tropical tropospheric width, motivating study of the width of the stratospheric tropics and potential metrics. In the second chapter, directly measured chemical tracers form a useful basis for stratospheric tropical width estimates and two new tracer-based metrics are developed. These metrics are applied to assess relationships between tropospheric and stratospheric width changes and to study stratospheric transport processes.
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\nSecond, unanswered questions about the extent of stratospheric modulation and disruptions to it confound efforts to distinguish anthropogenic sources of trace gases, such as continued production that violate the Montreal Protocol, from natural processes. The third chapter studies seasonal synchronizations between the dominant mode of lower stratospheric variability on one-to-five-year timescales and advective contributions to temporal changes in N₂O and CFC-11. These synchronizations influence the abundance of chemical species in the atmosphere from the stratosphere to the surface.
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\nThird, the close association between lower stratospheric temperatures and upwelling facilitate inferring the injection of trace gases and aerosols into the stratosphere. In the fourth chapter, a regional study of the response of lower stratospheric temperatures above the Asian summer monsoon anticyclone is found to obey quasigeostrophic theory. Lower stratospheric monsoon temperatures from both radiosondes and reanalysis have been cooling over the observational record, suggesting enhanced upwelling through the monsoon anticyclone, and increased stratospheric dehydration.
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\nThe second system this dissertation focuses on is layered viscous flow. The fifth chapter resents a theoretical and experimental study of two-layer viscous flows on inclined surfaces, commonly found in environmental and industrial flows. The general model reveals a rich variety of flow regimes for different modes of release. These phenomena are likely to underlie more complex examples of layered flows, for which the model and analytical inroads revealed here provide a basis for generalization.
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\nThe sixth chapter is motivated by rapid ice flow including icestreams and glacier surge events, which are quasiperiodic fast flow episodes. Mechanisms for surge initiation remain unknown and debated. Here, evidence that many surge-type glaciers are underlain by layers of fine, deformable sediment spurs a stability analysis of the ice-sediment interface. The assessment reveals positive feedback loops and instability mechanisms between the subglacial sediment and overlying ice.
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\nThe third layered phenomenon this dissertation addresses is stellar turbulence. Shear-driven turbulence in stratified stellar interiors provides an important source of vertical transport of heat, momentum, and chemical tracers. Motivated by numerical evidence of anisotropic flows, the seventh chapter presents a multiscale analysis that identifies turbulent behaviour regimes.
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\nThe eighth and final chapter concludes this dissertation by presenting an outlook and possible directions for future research.

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 categoriesMeta-epidemiology (narrow)
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Not applicable · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.602
Threshold uncertainty score1.000

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0010.001
Meta-epidemiology (broad)0.0010.000
Bibliometrics0.0000.002
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0010.000
Research integrity0.0010.002
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 head0.029
GPT teacher head0.329
Teacher spread0.300 · 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.

Study designNot applicable
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

Citations0
Published2023
Admission routes1
Has abstractyes

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