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Titel |
Characterisation of a stratospheric sulfate plume from the Nabro volcano using a combination of passive satellite measurements in nadir and limb geometry |
VerfasserIn |
M. J. M. Penning de Vries, S. Dörner, J. Puķīte, C. Hörmann, M. D. Fromm, T. Wagner |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1680-7316
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Digitales Dokument |
URL |
Erschienen |
In: Atmospheric Chemistry and Physics ; 14, no. 15 ; Nr. 14, no. 15 (2014-08-14), S.8149-8163 |
Datensatznummer |
250118946
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Publikation (Nr.) |
copernicus.org/acp-14-8149-2014.pdf |
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Zusammenfassung |
The eruption of the Nabro volcano (Eritrea), which started on 12 June 2011,
caused the introduction of large quantities of SO2 into the lower
stratosphere. The subsequently formed sulfate aerosols could be detected for
several months following the eruption. It is generally assumed that the
formation of sulfate aerosols in the stratosphere is a relatively slow
process, but in plumes from explosive eruptions significant amounts of
aerosols have been seen to form within a few hours.
We show that sulfate aerosols were present in the lower stratosphere within
hours of the onset of the eruption of Nabro. Evidence comes from nadir UV
Aerosol Index (UVAI) and SO2 measurements by SCIAMACHY, GOME-2 and OMI,
and limb aerosol measurements by SCIAMACHY. The sulfate plume displays
negative UVAI in the western part of OMI's swath and positive UVAI in the
eastern part – an effect that is due to the strong viewing angle dependence
of UVAI and can only be caused by a high-altitude (>11 km),
non-absorbing (single-scattering albedo >0.97) aerosol plume.
For the retrieval of the aerosol profile from limb measurements, the
horizontal dimensions and the position of the aerosol plume need to be taken
into account, otherwise both extinction and layer height may be
underestimated appreciably. By combining nadir SO2 column density and
UVAI with limb aerosol profiles, a stratospheric plume from Nabro could be
tracked from 13 to 17 June, before the plumes from later, lower-altitude
explosions started interfering with the signal. Our findings are in agreement
with ground-based lidar and sun-photometer data from an MPLNET/AERONET
station in Israel and with data from the satellite-borne CALIOP lidar. |
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