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Eruption column height: a comparison between ground and satellite measurements
Author(s)
Type
Abstract
Language
English
Obiettivo Specifico
4V. Vulcani e ambiente
Status
Published
Conference Name
Issued date
April 27, 2014
Conference Location
Vienna, Austria
Keywords
Abstract
The eruption column height estimation is an essential parameter to evaluate the total mass eruption rate, the gas and
aerosol plume dispersal and retrievals. The column height may be estimated using different systems (e.g. satellite,
aircraft and ground observations) which may present marked differences. In this work we use the calibrated images
collected by the video-surveillance system of the Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio
Etneo, from the visible camera located in Catania, 27 km from the vent. The analysis is carried out on twenty
lava fountains from the New South East Crater during the recent Etna explosive activity. Firstly, we calibrated
the camera to estimate its intrinsic parameters and the full camera model. Furthermore, we selected the images
which recorded the maximum phase of the eruptive activity. Hence, we applied an appropriate correction to take
into account the wind effect. The column height was also evaluated using SEVIRI and MODIS satellite images
collected at the same time of the video camera measurements. The satellite column height retrievals is realized by
comparing the 11 m brightness temperature of the most opaque plume pixels with the atmospheric temperature
profile measured at Trapani WMO Meteo station (the nearest WMO station to the Etnean area). The comparison
between satellite and ground data show a good agreement and the column altitudes ranges between 7.5 and 9 km
(upper limit of the camera system). For nine events we evaluated also the thickness of the volcanic plumes in the
umbrella region (near the vent) which ranges between 2 and 3 km. The proposed approach help to quantitatively
evaluate the column height that may be used by volcanic ash dispersal and sedimentation models for improving
forecasts and reducing risks to aviation during volcanic crisis.
aerosol plume dispersal and retrievals. The column height may be estimated using different systems (e.g. satellite,
aircraft and ground observations) which may present marked differences. In this work we use the calibrated images
collected by the video-surveillance system of the Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio
Etneo, from the visible camera located in Catania, 27 km from the vent. The analysis is carried out on twenty
lava fountains from the New South East Crater during the recent Etna explosive activity. Firstly, we calibrated
the camera to estimate its intrinsic parameters and the full camera model. Furthermore, we selected the images
which recorded the maximum phase of the eruptive activity. Hence, we applied an appropriate correction to take
into account the wind effect. The column height was also evaluated using SEVIRI and MODIS satellite images
collected at the same time of the video camera measurements. The satellite column height retrievals is realized by
comparing the 11 m brightness temperature of the most opaque plume pixels with the atmospheric temperature
profile measured at Trapani WMO Meteo station (the nearest WMO station to the Etnean area). The comparison
between satellite and ground data show a good agreement and the column altitudes ranges between 7.5 and 9 km
(upper limit of the camera system). For nine events we evaluated also the thickness of the volcanic plumes in the
umbrella region (near the vent) which ranges between 2 and 3 km. The proposed approach help to quantitatively
evaluate the column height that may be used by volcanic ash dispersal and sedimentation models for improving
forecasts and reducing risks to aviation during volcanic crisis.
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