The Total Ozone Mapping Spectrometer (TOMS) instrument, flown on 4 satellite missions since 1978 (Nimbus-7, Meteor-3, ADEOS, and Earth Probe), measured SO2 emissions during all 14 eruptions of Nyamuragira between 1980 and 2004. This unique dataset indicates that Nyamuragira is the largest volcanic source of SO2 on Earth over the last 25 years, although its emissions have been distributed over 14 effusive eruptions rather than a single explosive event, limiting its impact on climate. TOMS images of SO2 plumes from Nyamuragira and Nyiragongo are available.
The Ozone Monitoring Instrument (OMI), launched on NASA's EOS/Aura satellite in July 2004, has now replaced TOMS and will monitor SO2 emissions from future eruptions in the Virunga. OMI has much improved SO2 sensitivity over TOMS and can also measure passive degassing. OMI has detected the tropospheric plume emitted by Nyiragongo's active lava lake on most days since the sensor was deployed. Links to OMI images and data will be available shortly.
STOP PRESS A new eruption of Nyamulagira began on 27 November 2006 at around 2000UT; its 15th eruption since 1980. The links below correspond to daily OMI images of the vast SO2 cloud being produced by this eruption. Numbers in parentheses are estimated SO2 loadings.
Nov 28 (0.21 Tg), Nov 29 (0.46 Tg), Nov 30 (0.68 Tg), Dec 1 (0.77 Tg), Dec 2 (0.78 Tg), Dec 3 (0.71 Tg), Dec 4 (0.59 Tg)
The image below shows monthly average SO2 columns measured by OMI over eastern DR Congo from October 2004 - December 2008. SO2 emissions from the November 2006 eruption of Nyamuragira have been filtered out. These monthly averages show the variation in SO2 emissions from Nyiragongo and seasonal changes in wind speed and direction, and hence plume dispersion.