HR: 0830h
AN: V11C-0509    [PDF]
TI: Observing Popocatepetl's Volcanic Clouds Using MODIS Infrared Data
AU: * Matiella, M
EM: mamatiel@mtu.edu
AF: Dept. of Geological Engineering and Sciences, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931-1295 United States
AU: Delgado-Granados, H
EM: hugo@tonatiuh.igeofcu.unam.mx
AF: Instituto de Geofisica, Universidad Nacional Autonoma de Mexico, UNAM, Ciudad Universitaria Coyoacan, Mexico DF, 04510 Mexico
AU: Rose, W I
EM: raman@mtu.edu
AF: Dept. of Geological Engineering and Sciences, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931-1295 United States
AU: Watson, I
EM: watson@mtu.edu
AF: Dept. of Geological Engineering and Sciences, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931-1295 United States
AB: Popocatepetl Volcano, Mexico, is a tropical volcano with significant and persistent emissions of SO$_{2}$ and ash. These emissions pose significant hazards to the large population in close proximity to the volcano and are an important indicator of eruptive activity (Love et al., 1998, Nature 396: 563-566). Moderate Resolution Imaging Spectroradiometer (MODIS) satellite imagery provides us with a synoptic perspective of volcanic emissions and atmospheric interactions, information unavailable from ground-based or aircraft studies, which can be useful for hazard mitigation. We report on MODIS data during December 2000 and January 2001 coincident with abundant emissions based on COSPEC data. SO$_{2}$ masses are retrieved using the 7.3 $\mu$m and 8.6 $\mu$m absorption features of SO$_{2}$ (7.3 $\mu$m method after Prata et al, in press, AGU Volcanism Atmospheric Monograph; 8.6 $\mu$m method after Realmuto et al, 1997, J. Geophys Res 102: 15057-15072). Ash masses are retrieved using silicate absorption features at 11 $\mu$m and 12 $\mu$m (Wen \& Rose, 1994, J Geophys Res 99: 5421-5431). Furthermore, this data set tests the accuracy of the algorithms and the conditions under which the algorithms work best, and can be compared to COSPEC measurements taken by Popocatepetl's monitoring team. We found that MODIS data often showed more than one volcanic cloud. For example, one MODIS image collected January 23rd, 2001, at 0450 UT, shows four large eruptions that have dispersed volcanic clouds over an extensive area of Mexico. Using upper air data and monitoring records, the movements of the 4 ash clouds are fit with eruption times and winds, and using retrieval data for SO$_{2}$ and ash we can derive a time based SO$_{2}$ and fine ash emission record. The results of these retrievals compliment ground-based measurements which cannot measure large scale eruptions.
DE: 8409 Atmospheric effects (0370)
DE: 8419 Eruption monitoring (7280)
DE: 8494 Instruments and techniques
SC: Volcanology, Geochemistry, Petrology [V]
MN: 2003 Fall Meeting