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Titel |
Organohalogen emissions from saline environments – spatial extrapolation using remote sensing as most promising tool |
VerfasserIn |
K. Kotte, F. Löw, S. G. Huber, T. Krause, I. Mulder, H. F. Schöler |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1726-4170
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Digitales Dokument |
URL |
Erschienen |
In: Biogeosciences ; 9, no. 3 ; Nr. 9, no. 3 (2012-03-29), S.1225-1235 |
Datensatznummer |
250006857
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Publikation (Nr.) |
copernicus.org/bg-9-1225-2012.pdf |
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Zusammenfassung |
Due to their negative water budget most recent semi-/arid regions are
characterized by vast evaporates (salt lakes and salty soils). We recently
identified those hyper-saline environments as additional sources for a
multitude of volatile halogenated organohalogens (VOX). These compounds can
affect the ozone layer of the stratosphere and play a key role in the
production of aerosols. A remote sensing based analysis was performed in the
Southern Aral Sea basin, providing information of major soil types as well
as their extent and spatial and temporal evolution. VOX production has been
determined in dry and moist soil samples after 24 h. Several C1- and C2
organohalogens have been found in hyper-saline topsoil profiles, including
CH3Cl, CH3Br, CHBr3 and CHCl3. The range of
organohalogens also includes trans-1,2-dichloroethene (DCE), which is
reported here to be produced naturally for the first time. Using MODIS time
series and supervised image classification a daily production rate for DCE
has been calculated for the 15 000 km2 ranging research area in the
southern Aralkum. The applied laboratory setup simulates a short-term change
in climatic conditions, starting from dried-out saline soil that is
instantly humidified during rain events or flooding. It describes the
general VOX production potential, but allows only for a rough estimation of
resulting emission loads. VOX emissions are expected to increase in the
future since the area of salt affected soils is expanding due to the
regressing Aral Sea. Opportunities, limits and requirements of satellite
based rapid change detection and salt classification are discussed. |
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