HR: 14:40h
AN: V12E-05    [PDF]
TI: Investigation Of Volcanic Gas Emission By MAX-DOAS And I-DOAS
AU: * Bobrowski, N
EM: nbobrows@iup.uni-heidelberg.de
AF: Institut fuer Umweltphysik, INF229, Heidelberg, 69120 Germany
AU: Lohberger, F
EM: Falko.Lohberger@iup.uni-heidelberg.de
AF: Institut fuer Umweltphysik, INF229, Heidelberg, 69120 Germany
AU: Hoenninger, G
EM: Gerd.Hoenninger@ec.gc.ca
AF: Meteorological Service of Canada, 4905 Dufferin St., Toronto, M3H 5T4 Canada
AU: Platt, U
EM: Ulrich.Platt@iup.uni-heidelberg.de
AF: Institut fuer Umweltphysik, INF229, Heidelberg, 69120 Germany
AB: Simultaneously measurements of BrO, SO$_2$ and other trace gases in volcanic plumes were made. With a Mini - MAX-DOAS (Multi Axis Differential Optical Absorption Spectroscopy) an image of the BrO and SO$_2$ distribution in a volcanic plume was determined. Reactive bromine in the form of BrO was found to be is present in volcanic plumes and mixing ratios up to 1 ppb were determined at Soufriere Hills Volcano on Montserrat. These give volcanoes the potential to be a BrO source that is at least locally important and may be even relevant on a global scale. BrO plays an important role in the tropospheric and stratospheric ozone cycle. BrO is - in comparison to HBr - not water-soluble and can therefore reach the stratosphere during large eruptions or otherwise is dispersed in the troposphere. MAX-DOAS and I-DOAS (Imaging-DOAS) are optical remote-sensing methods using scattered sunlight. They allow highly sensitive and specific detection of many trace gases simultaneously (specific molecules not just elements) and can measure the temporal and spatial variation of these gases. The Mini-MAX-DOAS is lightweight, robust and has a very low power consumption, which permits measurements of atmospheric trace gases in remote locations, such as volcanoes often are. The I-DOAS allows taking two-dimensional pictures from a volcanic plume with very high spatial resolution. Therefore it provides useful information about the chemical composition and its variability in a volcanic plume and the possibility to study plume dispersal and chemical transformations. An introduction in these techniques that are newly applied in volcanic gas research will be given as well as several measurement results from different volcanic sites.
DE: 1749 Volcanology, geochemistry, and petrology
SC: Volcanology, Geochemistry, Petrology [V]
MN: 2003 Fall Meeting