Carbonyl sulfide (OCS) variability with latitude in the atmosphere

G. Krysztofiak (1) , Yao Veng Té (2) , Valéry Catoire (1) , Gwenaël Berthet (1) , Geoffrey C. Toon (3) , Fabrice Jégou (1) , Pascal Jeseck (2) , C Robert (1)

1 LPC2E - Laboratoire de Physique et Chimie de l'Environnement et de l'Espace
2 LPMAA - Laboratoire de Physique Moleculaire pour l'Atmosphere et l'Astrophysique
3 JPL - Jet Propulsion Laboratory

Carbonyl sulfide (OCS) is an important precursor of sulfate aerosols and consequently a key species in stratospheric ozone depletion. SPIRALE and SWIR balloon-borne instruments have flown in the tropical region and in the Arctic polar region, and ground-based measurements have been performed by QualAir FTS instrument in Paris. Partial and total columns and vertical profiles have been obtained to study the OCS variability with altitude, latitude and season. The annual total column variation in Paris reveals a seasonal variation with a maximum in April-June and a minimum in November-January. Total column measurements above Paris and from SWIR balloon-borne instrument are compared with several MkIV measurements, several NDACC stations, aircraft, ship and balloon measurements to highlight the OCS total column decrease from tropical to polar latitudes. OCS high resolution in situ vertical profiles have been measured for the first time in the altitude range between 14 and 30 km at tropical and polar latitudes. OCS profiles are compared with ACE satellite measurements and show good agreement. Using OCS:N2O correlation from SPIRALE, OCS stratospheric lifetime has been accurately determined. We find a stratospheric lifetime of 70±20 years at polar latitude and 58±14 years at tropical latitude leading to a global stratospheric sink of 54±14 Gg S yr-1.

Domains: Earth and Planetary Astrophysics [astro-ph.EP]; Earth and Planetary Astrophysics [astro-ph.EP]

G. Krysztofiak, Yao Veng Té, Valéry Catoire, Gwenaël Berthet, Geoffrey C. Toon, et al.. Carbonyl sulfide (OCS) variability with latitude in the atmosphere. Atmosphere-Ocean, 2015, 53, pp.89-101. ⟨10.1080/07055900.2013.876609⟩. ⟨insu-00906943⟩