Sulfur-isotope anomalies recorded in Antarctic ice cores as a potential proxy for tracing past ozone layer depletion events - OTELo - Observatoire Terre et Environnement de Lorraine Accéder directement au contenu
Article Dans Une Revue PNAS Nexus Année : 2022

Sulfur-isotope anomalies recorded in Antarctic ice cores as a potential proxy for tracing past ozone layer depletion events

Résumé

Changes in the cosmic-ray background of the Earth can impact the ozone layer. High-energy cosmic events [e.g. supernova (SN)] or rapid changes in the Earth's magnetic field [e.g. geomagnetic Excursion (GE)] can lead to a cascade of cosmic rays. Ensuing chemical reactions can then cause thinning/destruction of the ozone layer—leading to enhanced penetration of harmful ultraviolet (UV) radiation toward the Earth's surface. However, observational evidence for such UV “windows” is still lacking. Here, we conduct a pilot study and investigate this notion during two well-known events: the multiple SN event (≈10 kBP) and the Laschamp GE event (≈41 kBP). We hypothesize that ice-core-Δ33S records—originally used as volcanic fingerprints—can reveal UV-induced background-tropospheric-photochemical imprints during such events. Indeed, we find nonvolcanic S-isotopic anomalies (Δ33S ≠ 0‰) in background Antarctic ice-core sulfate during GE/SN periods, thereby confirming our hypothesis. This suggests that ice-core-Δ33S records can serve as a proxy for past ozone-layer-depletion events.
Fichier principal
Vignette du fichier
pgac170.pdf (1.34 Mo) Télécharger le fichier
Origine : Publication financée par une institution
licence : CC BY - Paternité

Dates et versions

hal-04142969 , version 1 (12-09-2022)
hal-04142969 , version 2 (27-06-2023)

Licence

Paternité

Identifiants

Citer

Sanjeev Dasari, Guillaume Paris, Julien Charreau, Joel Savarino. Sulfur-isotope anomalies recorded in Antarctic ice cores as a potential proxy for tracing past ozone layer depletion events. PNAS Nexus, 2022, 1 (4), pgac170. ⟨10.1093/pnasnexus/pgac170⟩. ⟨hal-04142969v2⟩
236 Consultations
38 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More