Measuring CO<sub>2</sub> Exchange over the Hydromagnesite-Magnesite Playas in Atlin, B.C.
Bibliographic record
Abstract
The hydromagnesite-magnesite playas in Atlin, BC, are an important site for demonstrating carbonate mineral stability at the Earth's surface [1]. The playas represent a natural analogue for carbon capture and storage via ex-situ carbon mineralization. Additionally, Power et al. (2014) suggested that the playas degas CO 2 during carbonate mineral precipitation from the Mg-HCO 3 rich groundwater. The complex interactions between minerals, fluids and the atmosphere make Atlin an ideal site to test methods for measuring CO 2 fluxes in a predominantly abiotic geologic setting. Eddy covariance (EC) and dynamic closed chamber (DCC) systems, combined with meteorological sensors, were co-located to directly quantify rates and characterize processes governing the CO 2 flux across the playa-atmosphere interface. Data were collected continuously over 27 days in August 2020 and 12 days in 2021. The results from the DCC method show distinct diurnal oscillation of CO 2 fluxes, with average daytime fluxes of +0.170.36 mol m -2 s -1 and nighttime fluxes of -0.240.32 mol m -2 s -1 (positive upward and negative downward). The near-zero flux measured via the DCC method indicates minimal net exchange of carbon across the playaatmosphere interface. These observations imply that DCCmeasured CO 2 fluxes are governed predominantly by changes in CO 2 solubility in alkaline porewater related to diurnal temperature fluctuations and variations in CO 2 concentrations in ambient air above the ground surface. However, the EC data show a continuous positive flux averaging +1.39 mol m -2 s -1 (2020) and +1.11 mol m -2 s -1 (2021). The net flux of CO 2 measured by EC is from a source undetected by the DCC (i.e. CO 2 imported laterally from surrounding forests or released through preferential pathways in the playa). The use of two flux measurement methods reveals the importance of the scale and location at which CO 2 flux processes occur at this site and the necessity of cross-validation between methods. These findings provide insights for the larger-scale application of these methods for monitoring and verification of ex-situ carbon mineralization at enhanced weathering sites.
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) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.017 | 0.001 |
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.
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; both teacher heads agree on what is shown here.
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".