HR: 17:45h
AN: V24A-08    [Abstracts]
TI: The effect of volcanic gases on quantitative temperature measurements using the FLIR thermal camera
AU: Sawyer, G
EM: gms26@cam.ac.uk
AF: Cambridge University, Department of Geography Downing Place, Cambridge, CB2 3EN United Kingdom
AU: * Burton, M R
EM: burton@ct.ingv.it
AF: INGV Catania, Piazza Roma, 2, Catania, CT 95123 Italy
AU: Oppenheimer, C
EM: co200@cam.ac.uk
AF: Cambridge University, Department of Geography Downing Place, Cambridge, CB2 3EN United Kingdom
AB: Ground-based thermal imagery is being increasingly used as a tool for volcano surveillance, however, the radiative transfer effect of volcanic gases and aerosols has been largely overlooked. This is potentially very important, as the concentrations of volcanic gas present in, for example, the summit crater of Stromboli may be very high. Here, we calculate the magnitude of the effect of volcanic and atmospheric gas absorptions on radiometric measurements collected with a FLIR thermaCAM PM695 during mild explosive events on Stromboli volcano, Italy. We use measurements of gas path amounts collected by Fourier transform infrared spectrometry to constrain a radiative transfer model and demonstrate that if the effect of absorptions by water vapour and sulphur dioxide is not accounted for then large systematic errors will be introduced in observed temperatures. We also examine the effect of a volcanic plume on the high resolution spectrum in the wavelength range of interest for the FLIR, and determine that aerosols and SiF₄ may well be ulterior sources of discrepancy between observed and actual temperatures.
DE: 8419 Volcano monitoring (7280)
DE: 8485 Remote sensing of volcanoes
DE: 8494 Instruments and techniques
SC: Volcanology, Geochemistry, Petrology [V]
MN: Fall Meeting 2005