Measurements of Atmospheric Ozone, NO2, OClO, and BrO at 80°N using UV Visible Spectroscopy
Bibliographic record
Abstract
The motivation for this thesis was to study chemical and dynamical processes in the Arctic stratosphere, using data from two ground-based spectrometers (GBSs). The GBSs took atmospheric trace gas measurements at the Polar Environment Atmospheric Research Laboratory (PEARL), which is located at Eureka, Nunavut, Canada (80.05°N, 86.42°W) and operated by the Canadian Network for the Detection of Atmospheric Change. The University of Toronto GBS took measurements at Eureka on a campaign basis from 1999 2011. The PEARL GBS was installed permanently at Eureka in 2006 and has taken measurements during the sunlit part of the year since then.\nGBS and other ground based ozone and NO2 column measurements were compared with Atmospheric Chemistry Experiment (ACE) and Optical Spectrograph and Infra Red Imaging System (OSIRIS) satellite measurements above Eureka. Ozone from all instruments agreed within 9.2%, while NO2 from most instruments, including the GBS, agreed to within 20%.\nOn 1 August 2008, a solar eclipse of 98% totality passed over Eureka. GBS NO2 increased to 1.84 times normal levels. This agrees with a ratio of 1.91 that was calculated using a photochemical model, adjusted for reduced sunlight during the eclipse.\nIn spring/winter 2011, up to 47% (250 DU) ozone loss was calculated using GBS and modeled passive ozone. This was the largest ozone loss in the 11 year GBS measurement record. GBS OClO was elevated, indicating chlorine activation and NO2 was low, suggesting denitrification. GBS, satellite, and chemical transport model data were used to investigate the 2011 vortex breakup. NOx transport led to middle stratosphere ozone loss within an anticyclone. Furthermore, isolated, or âfrozen-inâ, vortex and lower-latitude airmasses were observed following the vortex breakup.\nStratospheric BrO was retrieved from spring 2008 GBS zenith sky measurements, using an optimal estimation technique. GBS BrO was compared with OSIRIS and Ozone Monitoring Instrument (OMI) satellite data. Discrepancies are partly attributed to bromine explosions in the boundary layer. New off axis GBS measurements taken in spring 2010 are sensitive to boundary layer bromine. The combination of GBS stratospheric and tropospheric BrO measurements will be useful for future estimates of the Arctic bromine budget.
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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 | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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".