Optical monitoring of volcanic sulphur dioxide emissions - comparison between four different remote-sensing spectroscopic techniques
Författare
Summary, in English
The emissions of sulphur dioxide from the Italian volcanoes Mt. Etna and Stromboli were studied in ship-borne underpasses of their plumes. Four different optical spectroscopy techniques were used and inter-compared. All techniques utilise the absorption signature of the gas in the wavelength region of around 300 nm. A differential absorption lidar was employed in active gas concentration assessment. In parallel, a differential optical absorption spectroscopy system (DOAS) provided spectrally resolved absorption spectra, In one configuration the DOAS used a vertically looking telescope and the absorption of the skylight was studied, while a different DOAS implementation utilised the sun disc as the light source in slant-angle, long-path absorption measurements. Parallel measurements with the customary correlation spectroscopy method were also performed. Path length Monte Carlo simulations of the down-welling radiation through the volcanic plume at different sun altitude and azimuth angles have been performed taking into account also the effects of other geometric parameters as the plume height and extension. The results are discussed with special emphasis on systematic effects due to scattering.
Avdelning/ar
Publiceringsår
2002
Språk
Engelska
Sidor
267-284
Publikation/Tidskrift/Serie
Optics and Lasers in Engineering
Volym
37
Issue
2-3
Fulltext
- Available as PDF - 366 kB
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Dokumenttyp
Artikel i tidskrift
Förlag
Elsevier
Ämne
- Atom and Molecular Physics and Optics
Nyckelord
- correlation spectroscopy
- DOAS
- lidar
Status
Published
ISBN/ISSN/Övrigt
- ISSN: 0143-8166