Mercury fluxes and speciated concentrations above terrestrial surfaces in Canada during colder periods
Notice bibliographique
Résumé
Emission rates (fluxes) of gaseous elemental mercury (GEM) and concentration measurements of GEM, reactive gaseous mercury (RGM) and particle bound mercury (Hgp) were measured from different terrestrial surfaces in Canada in order to provide regional modelers with more reliable information on the behaviour of mercury in the environment during colder months. A micrometeorological flux gradient technique was used to infer the flux of GEM using a continuous two-level sampling system. Fluxes were measured from substrates (soils) containing low concentrations (< 1 [mu]g g-1) of mercury in the substrate but are representative of background levels in North America. In the Arctic, the highest depositional fluxes occurred during polar night and the largest emissions occurred when the tundra was first visible. The flux of GEM was approximately zero during atmospheric depletion events (AMDEs) demonstrating that mercury is not being deposited as GEM to the snow pack during these episodes. In Southern Ontario during the late fall, depositional fluxes of GEM were significantly elevated during a biosolids application event, although fluxes were only slightly increased during substantial rain events due to the surface soil moisture being near field capacity throughout the study. During the winter in Southern Ontario, GEM emission fluxes were 3 times higher during periods of snow cover than without. GEM fluxes were also significantly influenced by soil freezing, resulting in fluxes over 2 times greater when the freezing duration increased from 6 to 20 continuous days. Concentrations of RGM and Hgp in the Arctic were elevated during periods of low wind speeds. As the air temperature and specific humidity increased, higher levels of RGM were noted and colder temperatures with low specific humidities resulted in elevated Hgp concentrations. A biosolids application event during the fall in Southern Ontario resulted in elevated levels of RGM and He while harvesting of corn produced increased concentrations of Hgp and GEM. During the winter, elevated levels of GEM, RGM and Hgp were noted when the winds prevailed from urbanized areas with light industry and known atmospheric releases of mercury. The highest hourly averaged GEM concentrations occurred when the net radiation was highest. The highest concentrations of Hgp and RGM occurred throughout the night with the greatest variations occurring in the evening for He and around mid-day for RGM. On an averaged day, emissions of GEM occurred throughout the night when the soil temperatures were the lowest and deposition occurred around mid-day when the soil temperature was the highest.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,001 | 0,001 |
| Études des sciences et des technologies | 0,001 | 0,000 |
| Communication savante | 0,001 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».