Viscosity, Glass Formation, and Mixing Times within Secondary Organic Aerosol from Biomass Burning Phenolics
Bibliographic record
Abstract
Biomass burning events emit large amounts of phenolic compounds, which are oxidized in the atmosphere and form secondary organic aerosol (SOA). Using the poke-flow technique, we measured relative humidity (RH)-dependent viscosities of SOA generated by the oxidation of three biomass burning phenolic compounds: catechol, guaiacol, and syringol. All systems had viscosity < 3 × 10 3 Pa s at RH ≳ 40% and > 2 × 10 8 Pa s at RH ≲ 3% at room temperature. At RH values of 0–10%, the viscosities of these SOA were at least 2 orders of magnitude higher than the viscosity of primary organic aerosol from biomass burning. We also developed a parameterization for predicting the viscosity of phenolic biomass burning SOA as a function of RH and temperature. Based on this parameterization, the viscosity of phenolic biomass burning SOA is strongly dependent on both RH and temperature. Under dry conditions, phenolic biomass burning SOA is highly viscous at room temperature (∼10 9 Pa s) and becomes a glass (viscosity > 10 12 Pa s) when the temperature is < 280 K. For tropospheric temperature and RH values, phenolic biomass burning SOA is often in a liquid state (η < 10 2 Pa s) below ∼2 km altitude, a semi-solid state (10 2 < η < 10 12 Pa s) between ∼2 and ∼9 km, and a glassy state (η > 10 12 Pa s) above ∼9 km. Furthermore, the mixing time of organic molecules in a 200 nm phenolic biomass burning SOA particle exceeds 1 h above 3 km in the troposphere.
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 | 0.000 | 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 | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".