Mass-independent sulfur isotopic compositions in stratospheric volcanic eruptions.
The observed mass-independent sulfur isotopic composition (Delta33S) of volcanic sulfate from the Agung (March 1963) and Pinatubo (June 1991) eruptions recorded in the Antarctic snow provides a mechanism for documenting stratospheric events. The sign of Delta33S changes over time from an initial positive component to a negative value. Delta33S is created during photochemical oxidation of sulfur dioxide to sulfuric acid on a monthly time scale, which indicates a fast process. The reproducibility of the results reveals that Delta33S is a reliable tracer to chemically identify atmospheric processes involved during stratospheric volcanism.
Baroni
Mélanie
M
Laboratoire de Glaciologie et Géophysique de l'Environnement, CNRS/Université Joseph Fourier, 38400 St. Martin d'Hères, France. baroni@lgge.obs.ujf-grenoble.fr
Thiemens
Mark H
MH
Delmas
Robert J
RJ
Savarino
Joël
J