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Record W4220743366 · doi:10.5194/egusphere-egu22-8771

Airborne emissions of methane at offshore oil platforms in Newfoundland and Labrador, Canada

2022· preprint· en· W4220743366 on OpenAlexaffabout
Afshan Khaleghi, Katlyn MacKay, Évelise Bourlon, Martin Lavoie, Andrea Darlington, Lesley James, David Risk

Bibliographic record

Venuenot available
Typepreprint
Languageen
FieldEnvironmental Science
TopicAtmospheric and Environmental Gas Dynamics
Canadian institutionsMemorial University of NewfoundlandEnvironment and Climate Change CanadaSt. Francis Xavier University
Fundersnot available
KeywordsMethaneSubmarine pipelineEnvironmental scienceEmission intensityTransectMethane emissionsEmission inventoryMeteorologyAtmospheric sciencesGreenhouse gasOceanographyAir quality indexGeographyGeologyEngineeringChemistry

Abstract

fetched live from OpenAlex

In Canada, offshore oil production facilities are exempt from new methane mitigation requirements that apply to onshore producers. Since onshore oil and gas operations have been shown in Canada to emit more methane than is reported in the federal inventory, it is reasonable to question methane emission levels, and intensity, of Canada’s offshore oil production. In this study, we measured methane emissions from an aircraft equipped with Picarro 2210-i gas analyzer and Aventech wind measurement system (AIMMs_30). The top-down emission rate retrieval algorithm (TERRA) was used to calculate the emission rate using a mass balance technique. The algorithm was developed by Environment and Climate Change Canada and has been used previously for airborne emissions measurement campaigns around oil and gas facilities. In addition to mass balance estimates, we also derived estimates from downwind transects using a Gaussian Dispersion model. We flew around each of the 3 offshore facilities 3 times to ensure accurate measurements considering the unpredictable offshore weather conditions. Our emissions estimates were overall comparable with inventory estimates, which demonstrate a much lower methane emissions intensity than onshore oil production in western Canada. We compared our results against reported values for other aircraft-based measurement studies including those in the North Sea and the Gulf of Mexico. Although average measured emission rates in Eastern Canada are higher in absolute terms than similar platforms in the Gulf of Mexico or the North Sea, methane emission intensity is lower because production levels are very high. Keyword: Methane emission rate, Inventories, Mass balance, Top-down, Airborne measurement

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 score0.014
Threshold uncertainty score0.104

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0010.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0010.002
Science and technology studies0.0020.001
Scholarly communication0.0010.000
Open science0.0010.001
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0010.000

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 head0.007
GPT teacher head0.204
Teacher spread0.197 · 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

Citations0
Published2022
Admission routes2
Has abstractyes

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