Impact of aerosols on surface solar radiation and gross primary productivity over cropland and grassland ecosystems in North China
Bibliographic record
Abstract
The increasing atmospheric aerosols from anthropogenic activities in North China are anticipated to change the proportion of direct and diffuse solar radiation in global solar radiation. These solar radiation variations can further influence the photosynthesis of the sunlit and shaded leaves, thereby affecting the terrestrial productivity. The goal of this research was to investigate the impact of aerosols on surface solar radiation and gross primary productivity (GPP) over cropland and grassland ecosystems in North China. Results suggest a significant (p < 0.05) increasing proportion of small-size anthropogenic aerosols from 2000 to 2016 and a significant (p < 0.01) increasing tendency of diffuse solar radiation but a significant (p < 0.01) decreasing tendency of direct solar radiation over the period of 1959-2016 in North China. Aerosols have contributed around 63% to the variations of diffuse solar radiation during 2000-2016. Besides, new empirical methods perform well in estimating direct solar radiation at monthly and daily level. By considering aerosols using the remote sensing-based aerosol optical depth (AOD), the estimation accuracy of diffuse solar radiation is significantly improved. The comparison of GPP under two aerosol scenarios suggests that the presence of aerosols has reduced GPP of the sunlit leaves due to the declined direct solar radiation but enhanced that of the shaded leaves on account of the increased diffuse solar radiation above and below the canopy over both ecosystems. The aerosol-effect on GPP is more significant (p < 0.05) over cropland ecosystem given the more complex canopy structure during the peak period of the growing season. Besides, an AOD value of 0.3-0.6 with a diffuse fraction (the fraction of diffuse solar radiation in global solar radiation) around 30-40% can increase total GPP over cropland ecosystem. \nThis study highlights the significant impact of aerosols on surface solar radiation and gross primary productivity of terrestrial ecosystem over the highly-polluted region. The new empirical methods have improved the estimation accuracy of diffuse solar radiation at monthly and daily level. Meanwhile, the BEPS improved by the new empirical method can better model the terrestrial GPP over polluted regions.
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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 | 0.001 |
| Open science | 0.000 | 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".