SO2 FLUX MONITORING AT THE MEXICAN VOLCANOES POPOCATEPETL AND VOLCAN DE COLIMA, USING THE OZONE MONITORING INSTRUMENT (OMI)

The monitoring of sulfur dioxide (SO₂) emissions in volcanic plumes can give us information about the evolution of a magmatic system and can indicate future eruptions. Popocatépetl and Colima volcanoes are México’s most active volcanoes and are excellent targets to study the emissions of this volcanic gas. Forty-two satellite images from the Ozone Monitoring Instrument (OMI) were downloaded and processed with the OMIplot program, to determine SO₂ masses and fluxes from 2007 to 2012. The use of HYSPLIT was necessary to determine the altitude of the plumes that were not available in volcanic activity reports, and atmospheric soundings were used to determine the wind speed of the plumes. Only three images showed plumes from Colima volcano, which produced an average SO₂ mass of 500 tons and an average SO₂ flux of 1000 tons per day (t/d). Popocatépetl is one of the largest emitters of SO₂ in the world, and on April-May 2012 it started its most recent eruptive episode, which continues to the present time. The data from this research demonstrated that the volcano’s SO₂ fluxes increased before the beginning of the main eruptive episode in April-May 2012 and have decreased since May. The average SO₂ mass in the plumes was ~1350 tons in the period 2007-April 2012 and ~1850 tons in the period May-October 2012. The average SO₂ flux was of ~3150 t/d in the period 2007-April 2012 and ~2170 t/d in the period May-October 2012. Based on the results of this research Popocatépetl contributes ~0.9 teragrams per year of SO₂ to the global volcanic sulfur budget.