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Record W2778065734

Transport of very short-lived substances from the Indian Ocean to the stratosphere through the Asian monsoon

2017· dissertation· en· W2778065734 on OpenAlexaboutno aff
Alina Fiehn

Bibliographic record

VenueHelmholtz Centre for Ocean Research Kiel (GEOMAR) · 2017
Typedissertation
Languageen
FieldEarth and Planetary Sciences
TopicAtmospheric Ozone and Climate
Canadian institutionsnot available
FundersUniversitetet i OsloEuropean Centre for Medium-Range Weather ForecastsGEOMAR Helmholtz-Zentrum für Ozeanforschung KielBundesministerium für Bildung und ForschungNational Aeronautics and Space Administration
KeywordsStratosphereOzone layerOzone depletionOzoneBromineAtmospheric sciencesMontreal ProtocolEnvironmental scienceBromoformMethyl iodideChemistryClimatologyEnvironmental chemistryGeology
DOInot available

Abstract

fetched live from OpenAlex

Anthropogenic halogenated substances cause the ozone hole above Antarctica through catalytic ozone destruction and depletion of the stratospheric ozone layer, which shields the Earth from harmful ultraviolet radiation. Their emissions were regulated through the Montreal Protocol in 1989. Since the beginning of the 21st century, the amount of chlorine and bromine in the stratosphere from long-lived ozone depleting substances (ODS) has been decreasing and stratospheric ozone has started to increase slowly. Under these circumstances the importance of natural halogenated substances for atmospheric composition and chemistry will increase in the future. Trace-gases with atmospheric lifetimes of less than half a year belong to the so-called very short-lived substances(VSLS). The most important bromine containing VSLS bromoform (CHBr3, 17 days lifetime) and dibromomethane (CH2Br2, 150 days) from marine sources currently contribute about 25% to the observed stratospheric bromine loading. In addition, the short-lived VSLS methyl iodide (CH3I, 3.5 days) contributes to stratospheric iodine levels. Sulfur containing compounds, such as dimethylsulfide (DMS, 1 day), also influence stratospheric ozone. Sulfur supplies the stratospheric aerosol layer, which amplifies heterogeneous chemical ozone depleting reactions under high chlorine levels. DMS is a potential source of sulfur to the stratosphere. VSLS are naturally produced in the oceans by phytoplankton, macro algae, and photochemistry. They are primarily transported to the stratosphere with deep convection in the tropics and mainly enter the stratosphere over the Pacific warm pool in boreal winter and the Asian monsoon region in boreal summer. Major uncertainties still exist with respect to the oceanic emissions of halogenated VSLS from the Indian Ocean and their stratospheric entrainment through the Asian monsoon circulation. This thesis investigates the emissions of VSLS from the Indian Ocean and their transport to the stratosphere with novel combinations of data and modeling.

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 machine prediction

Teacher imitation

Not 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.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: Observational
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.077
Threshold uncertainty score0.152

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0010.002
Science and technology studies0.0010.000
Scholarly communication0.0020.001
Open science0.0000.001
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0040.001

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 head0.049
GPT teacher head0.314
Teacher spread0.266 · 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 source (direct Gemma or distilled Codex), 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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