Iodine in Sea Ice and the Polar Atmosphere
Notice bibliographique
Résumé
The volatilisation of iodine from the ocean and release to the atmosphere in the ice-covered polar regions has been studied. Laboratory experiments involving sea ice- and ice associated- diatoms have shown how the extreme conditions experienced in sea ice brine channels may lead to an increase in production of organic forms of iodine. Trends were observed in production by different classes of enzymes, active in the oxidative metabolism of the cell. An enhancement in trace gas concentrations due to the concentration effect of solvent volume reduction has also been demonstrated. Field campaigns have been undertaken in both the Arctic and Antarctic. Ship-based measurements in the Weddell Sea have implicated I2 as a key species in the mechanism of enhancement of atmospheric iodine in this region. Organic and inorganic forms of iodine were measured in seawater, sea ice and the atmosphere. On the Brunt ice shelf, enhanced concentrations of CH3I and C2H5I were measured in the snow firn air, with a diurnal profile, suggesting the snow may be a source of these compounds. These measurements have implications for atmospheric mixing ratios of IO, measured from the ship and validated by satellite data, and new particle formation. This is the first combined in situ study in Antarctica of organic and inorganic iodine compounds in sea water, ice and air. On the Western Antarctic Peninsula, IO was detected in the atmosphere, and seawater measurements of iodocarbons have demonstrated how organic compounds of iodine are enhanced during the phytoplankton bloom; these measurements are also a first. Iodine emissions in the sea ice zone were also quantified in two campaigns in the Arctic environment. High concentrations of halocarbons were measured in the brine of sea ice, with respect to the water below, in the Arctic Ocean. High atmospheric halocarbon mixing ratios and flux calculations have demonstrated the effect on the atmosphere above. In the Canadian sub-Arctic, where the ice had quite different physical properties, halocarbon concentrations were the highest ever recorded for some compounds, due to extreme concentration in very cold ice. The enhancement of organic forms of iodine in sea ice has therefore been demonstrated. I2 has been implicated as a key species in iodine emissions. Therefore, understanding has been furthered on the chemistry of iodine in sea ice and polar atmosphere.
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 distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,082 | 0,008 |
| Méta-épidémiologie (sens strict) | 0,001 | 0,001 |
| Méta-épidémiologie (sens large) | 0,002 | 0,000 |
| Bibliométrie | 0,001 | 0,002 |
| Études des sciences et des technologies | 0,002 | 0,016 |
| Communication savante | 0,002 | 0,001 |
| Science ouverte | 0,010 | 0,020 |
| Intégrité de la recherche | 0,001 | 0,015 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,024 | 0,024 |
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; les deux têtes enseignantes s’accordent sur ce qui est montré ici.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».