Isoprene emission inventory for the BOREAS southern study area
Bibliographic record
Abstract
An isoprene emission inventory for a section of boreal forest in central Saskatchewan was developed based on measured emission rates from the two dominant isoprene-emitting species, black spruce (Picea mariana (Mill.) BSP) and aspen (Populus tremuloides Michx.). The micrometeorological gradient technique was used to determine isoprene emission factors for establishing the inventory. Isoprene fluxes were measured during each of the three BOREAS intensive field campaigns (IFCs) during the 1994 growing season. Measured isoprene fluxes varied from 0.04 to 3.3 mg C m(-2) h(-1) over the black spruce canopy, and from 0.05 to 7.3 mg C m(-2) h(-1) above the aspen forest. Midsummer standard isoprene emission fluxes were 1.2 mg C m(-2) h(-1) and 2.3 mg C m(-2) h(-1) (at 20 degrees C and photosynthetically active radiation (PAR) of 1000 &mgr;mol m(-2) s(-1)) for black spruce and aspen, respectively. With light and temperature differences accounted for, there was an apparent seasonal effect on emissions with the highest rates in the summer months. The total amount of isoprene emitted from this section of the boreal forest was estimated to be 8.6 Gg C year(-1), which is about 1% of the net ecosystem carbon exchange for the study area. Aspen was the largest contributor, accounting for approximately 70% of the total. Branch enclosure and relaxed eddy accumulation measurements made at the black spruce site were used to define the uncertainty associated with flux measurements. Emission rates obtained by the gradient, enclosure and relaxed eddy accumulation methods showed good agreement when normalized to standard light and temperature conditions. The coefficient of variance between the three techniques was 12% for summer (IFC-2) measurements. The sensitivity of the annual isoprene emission total to the assignment of mean irradiance and temperature was also examined. If the hourly mean temperatures were increased by 1 degrees C throughout the growing season, annual carbon loss due to isoprene emission would increase by 14% from 8.6 to 9.8 Gg C.
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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 | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.008 | 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".