Extended observations of volcanic SO₂ and sulfate aerosol in the stratosphere

S. A. Carn (1) , N. A. Krotkov (2) , K. Yang (2) , R. M. Hoff (2) , A. J. Prata (3) , A. J. Krueger (1) , S. C. Loughlin (4, 5) , P. F. Levelt (6)

1 JCET - Joint Center for Earth Systems Technology [Baltimore]
2 GESTAR - Goddard Earth Sciences and Technology and Research
3 NILU - Norwegian Institute for Air Research
4 Montserrat Volcano Observatory
5 British Geological Survey [Edinburgh]
6 KNMI - Royal Netherlands Meteorological Institute

Sulfate aerosol produced after injection of sulfur dioxide (SO₂) into the stratosphere by volcanic eruptions can trigger climate change. We present new satellite data from the Ozone Monitoring Instrument (OMI) and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) missions that reveal the composition, structure and longevity of a stratospheric SO₂ cloud and derived sulfate layer following a modest eruption (0.2 Tg total SO₂) of Soufriere Hills volcano, Montserrat on 20 May 2006. The SO₂ cloud alone was tracked for over 3 weeks and a distance of over 20 000 km; unprecedented for an eruption of this size. Derived sulfate aerosol at an altitude of ~20 km had circled the globe by 22 June and remained visible in CALIPSO data until at least 6 July. These synergistic NASA A-Train observations permit a new appreciation of the potential effects of frequent, small-to-moderate volcanic eruptions on stratospheric composition and climate.

Domaines: Océan, Atmosphère

S. A. Carn, N. A. Krotkov, K. Yang, R. M. Hoff, A. J. Prata, et al.. Extended observations of volcanic SO₂ and sulfate aerosol in the stratosphere. Atmospheric Chemistry and Physics Discussions, 2007, 7 (1), pp.2857-2871. ⟨hal-00302609⟩