THE 1982 EL CHICHON ERUPTION: The Birth of Volcanic Sulfur Dioxide Monitoring from Space

1. Aura/OMI sulfur dioxide measurements THE 1982 EL CHICHON ERUPTION:The Birth of Volcanic Sulfur Dioxide Monitoring from Space 2006: Aura – “Top 10 discoveries” OMI monitors smelter SO2 emissions Ecuador/S. Colombia volcanoes La Oroya copper smelter Ilo copper smelter ~100 times improved sensitivity Krueger, AJ, “Sighting of El Chichon Sulfur Dioxide Clouds with the Nimbus 7 Total Ozone Mapping Spectrometer”, Science, 1983. Carn, S. A., et al, “Sulfur dioxide emissions from Peruvian copper smelters detected by the Ozone Monitoring Instrument, Geophys. Res. Lett”, 2007

2. OMI monitors SO2 emissions in South America Update Ecuador/S. Colombia volcanoes Ubinas volcano active (upwind of Ilo) La Oroya copper smelter PERU Smelter upgraded (90% SO2 captured) in Jan 2007 Average SO2 map from OMI Smelter decommissioned in June 2009 Ilo copper smelter Update to Carn et al., "Sulfur  dioxide emissions from Peruvian copper smelters detected by the  OMI", GRL, 2007. • Volcanic emissions from Ubinas volcano drift over Ilo in 2006-2007 • Upgraded sulfur capture technology at Ilo reduces SO2 emissions • Shut-down of La Oroya smelter in mid-2009; reduction expected

3. Public OMSO2 algorithm uses V8.5 TOMS ozone algorithm data Improvements arising from use of RR cloud top heights (OMCLDRR) - previous OMSO2 used TIR-derived cloud height climatology Four SO2 retrievals based on a-priori SO2 vertical profiles or center of mass altitude [CMA]: Planetary Boundary Layer (PBL): CMA = 0.9 km Lower tropospheric column (TRL): CMA = 2.5 km Mid-tropospheric column (TRM): CMA = 7.5 km UTLS column (STL): CMA = 17 km Limited validation of PBL [NE China] and STL [AIRS,TOMS] data to date Volcanic degassing is the principal source of SO2 in TRL-TRM data Current status OMSO2 v1.1.1 N. Krotkov (PI) K. Yang (algorithm development/ implementation) S. Carn (science/validation/applications) A. Krueger (PI, NRT volcanic data for aviation warning)

4. Long-term SO2 burdens over USA, Europe and China East-Aire’05 experiment 25.5 million tons of SO2 was emitted by Chinese factories in 2005 up 27% from 2000

5. Daily anthropogenic PBL data OMI SO2 burdens need cloud, aerosol and realistic SO2 profile correction !! • Noise ~1.5DU for ideal conditions (near nadir view, no clouds). Only plumes from strong anthropogenic sources of SO2 (such as smelters and coal burning power plants) and from strong regional pollution can be detected in pixel data. • Operational SO2 data need off-line correction for total ozone, SO2 profile, viewing geometry, clouds and aerosol effects.

6. Future work: Use on-line GOES-5 SO2 profile shape forecasts to account for SO2 lofting during long-range transport above PBL Use A-train cloud and aerosol data to correct AMF PBL product CMA = 0.9 km • Current data: • BRD algorithm [Krotkov et al 2006] • should be used only under optimal viewing conditions • constant AMF for CMA • ~0.9 km AMF= 0.3-0.4 SO2 sensitivity AMF= 1 -2

7. Current data require off-line AMF corrections for geometry, total ozone and aerosols. Future work: Measuring aerosol absorption in the UV wavelengths from ground[ N.Krotkov, J.Herman ] Use A-train cloud and aerosol data to correct AMF for mixed aerosol-cloudy scenes Off-line AMF corrections for ozone, geometry and aerosols

8. Current data Linear Fit algorithm [Yang et al 2007] The users can use the center of mass altitude (CMA) derived from SO2 vertical distribution to interpolate between the TRL (CMA=2.5km) and TRM (CMA=7.5km) values. Future algorithm Provide AK depending on OMI cloud information Better cloud information will be used from advanced A-train cloud-products Volcanic tropospheric data

9. Current data: LF algorithm [Yang et al 2007] OMI STL data continue 25+ years of TOMS volcanic data, but improved sensitivity extends the range of detection to smaller eruptions and older clouds LF algorithm underestimates large eruptions > 100DU A-train allows independent retrievals in UV/VIS/IR. Volcanic cloud SO2 burdens (<100DU) agree to within 20% Future work: Non-linear iterative retrieval for largest eruptions (Pinatubo) Volcanic Stratospheric (STL) data Earth Probe TOMS (11:00 am) Aqua AIRS (1:30 pm) Aura OMI (1:45 pm)

10. Anthropogenic SO2 GSFC: Mian Chin - GOCART modeling of the global sulfate cycle, aerosol pollution , effects on surface radiation (global dimming); UMCP: R. Dickerson, Can Li, Z. Li: Air quality and tropospheric chemistry studies; understanding long-range pollution transport. Dalhousie University : Aaron van Donkelaar, Randall Martin: Long-range Transport of Asian Sulfur Emissions NSF-VOCALS team: Effects of sulfur emissions in South America on the Southeast Pacific climate system U-Thessaloniki, Greece (Sulfur emissions in Eastern Europe) Data users: close collaboration • Volcanic SO2 • NRT Volcanic Applications: • NASA CAN for NRT volcanic cloud data for aviation hazards – A. Krueger • NOAA/NESDIS - G. Serafino, G. Vicente • Volcanic Ash Advisory Centers (VAACs) • European SACS BIRA/IASB NRT SO2 web site • USGS Volcano observatories: Alaska (AVO), Cascades (CVO), Hawaii (HVO) • Kamchatka Volcanic Eruption Response Team (KVERT), Petropavlovsk-Kamchatsky, Russia • Instituto Geofisico, Quito, Ecuador • INGEOMINAS, Colombia • Goma Volcano Observatory, DR Congo • IRD, Noumea, New Caledonia (monitoring volcanoes in Vanuatu) • GNS Science, New Zealand • AQ Applications: • U-Iowa and ANL: Air Quality Emission inventory and Air quality forecast DSS (PI: Carmichael and Styreets ; Ken Pickering, GSFC): comparing USA and Chinese emissions using regional models and OMI data;

11. New Spectral Fit algorithm Better stray light and Ring corrections Using SO2 profiles from GEOS-5 model Activities: 2008-2009 Activities: 2010-2011 • Better aerosol and cloud correction using A-train data and improvements based on comparison with models and measurements. Activities: 2012- • algorithm improvements to account for changes in instrument performance • Transition to future instruments