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| Titel |
Atmospheric transport and deposition of Indonesian volcanic emissions |
| VerfasserIn |
M. A. Pfeffer, B. Langmann, H.-F. Graf |
| 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 ; 6, no. 9 ; Nr. 6, no. 9 (2006-06-30), S.2525-2537 |
| Datensatznummer |
250003976
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| Publikation (Nr.) |
 copernicus.org/acp-6-2525-2006.pdf |
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| Zusammenfassung |
| A regional climate model has been used to study the transport and deposition of
sulfur (SO2 and SO42-) and PbCl2 emissions
from Indonesian volcanoes. The sensitivity of the atmospheric loss of these
trace species to meteorological conditions and their solubility was examined.
Two experiments were conducted: 1) volcanic sulfur
released as primarily SO2 and subject to transport, deposition, and
oxidation to SO42-; and 2) PbCl2 released as an infinitely
soluble passive tracer subject to only transport and deposition. The first experiment
was used to calculate SO2 loss rates from each active Indonesian volcano
producing an annual mean loss rate for all volcanoes of 1.1×10-5 s-1,
or an e-folding rate of approximately 1 day. SO2 loss rate was found to
vary seasonally, be poorly correlated with wind speed, and uncorrelated with
temperature or relative humidity. The variability of SO2 loss rates is found to
be correlated with the variability of wind speeds, suggesting that it is much more
difficult to establish a "typical'' SO2 loss rate for volcanoes that are exposed
to changeable winds. Within an average distance of 70 km away from the
active Indonesian volcanoes, 53% of SO2 loss is due to conversion to
SO42-, 42% due to dry deposition, and 5% due to lateral
transport away from the dominant direction of plume travel. The solubility of
volcanic emissions in water is shown to influence their atmospheric transport and
deposition. High concentrations of PbCl2 are predicted to be deposited near to
the volcanoes while volcanic S travels further away until removal from
the atmosphere primarily via the wet deposition of H2SO4. The
ratio of the concentration of PbCl2 to SO2 is found to
exponentially decay at increasing distance from the volcanoes. The more rapid
removal of highly soluble species should be considered when observing
SO2 in an aged plume and relating this concentration to other
volcanic species. An assumption that the ratio between the concentrations of
highly soluble volcanic compounds and SO2 within a plume
is equal to that observed in fumarolic gases is reasonable at small distances from
the volcanic vent, but will result in an underestimation of the emission flux of highly
soluble species. |
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