Fluvial carbon dioxide emission from the Lena River basin during spring flood
Bibliographic record
Abstract
Abstract. Greenhouse gas (GHG) emissions from inland waters of permafrost-affected regions is one of the key factor of circumpolar aquatic ecosystem response to climate warming and permafrost thaw. Riverine systems of central and eastern Siberia contribute a significant part of the water and carbon (C) export to the Arctic Ocean, yet their C exchange with the atmosphere remain poorly known due to lack of in-situ GHG concentration and emission estimates. Here we present the results of continuous in-situ pCO2 measurements over a 2600-km transect of the Lena River main stem and lower reaches of 20 major tributaries (together representing watershed area of 1,661,000 km2, 66 % of the Lena’s basin), conducted at the peak of the spring flood. The pCO2 in Lena (range 400–1400 µatm) and tributaries (range 400–1600 µatm) was oversaturated and remained generally stable (within ca. 20 %) over the night/day period and across the river channels. The pCO2 in tributaries increased northward with mean annual temperature decrease and permafrost increase; this change was positively correlated with C stock in soil and the proportion of deciduous needle-leaf forest and riparian vegetation. Based on gas transfer coefficients obtained from rivers of the Siberian permafrost zone, we calculated CO2 emission for the main stem and tributaries. Typical fluxes ranged from 1 to 2 g C m−2 d−1 (> 99 % CO2, < 1 % CH4) which is comparable with CO2 emission measured in Kolyma, Yukon and Mackenzie and permafrost-affected rivers in western Siberia. The areal C emissions from lotic waters of the Lena watershed were quantified via taking into account the total area of permanent and seasonal water of the Lena basin (28,000 km2). Assuming 6 months of the year of open water period and no emission under ice, the annual C emissions from the whole Lena basin range from 5 to 10 Tg C yr−1, which is comparable to the DOC and DIC lateral export to the Arctic Ocean.
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 machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| 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) | 0.000 | 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 source (direct Gemma or distilled Codex), 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".