Uptake of Gas-Phase SO<sub>2</sub> and H<sub>2</sub>O<sub>2</sub> by Ice Surfaces: Dependence on Partial Pressure, Temperature, and Surface Acidity
Bibliographic record
Abstract
The uptakes of gas-phase SO 2 and H 2 O 2 by ice surfaces have been investigated at temperatures from 213 to 238 K and from 10 -7 to 10 -4 Torr partial pressure. These experiments have been conducted in a low-temperature, coated-wall flow tube coupled to an electron-impact, quadrupole mass spectrometer which monitors changes in the SO 2 and H 2 O 2 partial pressure. The ice surfaces are formed by freezing liquid water. Unlike the uptakes of strong acids such as HNO 3 and HCl, the SO 2 and H 2 O 2 uptakes are fully reversible on the time scale of the experiment and the surface coverages are roughly a thousandth of a monolayer at 10 -6 Torr partial pressure and 228 K. The SO 2 uptakes scale with the square root of the partial pressure of the SO 2 gas, indicating that dissociation of the hydrated form of adsorbed SO 2 is occurring on the surface. The H 2 O 2 uptakes scale linearly with the H 2 O 2 partial pressure, indicating that dissociation does not occur. The uptakes are driven by H-bond interactions in this case. Support for these conclusions comes from uptake measurements with ice surfaces which were formed by freezing either acidic or basic aqueous solutions. Although the H 2 O 2 uptakes are independent of pH, the acidic ice surfaces considerably inhibit the SO 2 uptake and the basic surfaces enhance the SO 2 uptake. The results in this paper are consistent with atmospheric observations which show that both S(IV) and H 2 O 2 have low retention efficiencies after supercooled cloud droplets freeze, whereas the retention efficiency of HNO 3 is high. The uptakes are sufficiently small that scavenging of SO 2 and H 2 O 2 by ice clouds will not be significant.
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 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 | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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".