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| Titel |
Sulfur isotopic ratio of DMS and DMSP from Lake Kinneret |
| VerfasserIn |
Michal Sela-Adler, Ward Said-Ahmad, Werner Eckert, Alexey Kamyshny, Orit Sivan, Alon Amrani |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250100049
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| Publikation (Nr.) |
 EGU/EGU2014-15930.pdf |
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| Zusammenfassung |
| Volatile Organic sulfur compounds (VOSC) such as dimethylsulfide (DMS) are an
important source of biogenic sulfur to the atmosphere. The main precursor of DMS is
dimethylsulfoniopropionate (DMSP), a common osmolyte in marine algae. Atmospheric
release of VOS compounds contributes to the formation of sulfate aerosols. The latter are of
global importance due to their role as cloud-condensation nuclei. VOSC are abundant in
terrestrial environments as well and may be involved in important biogeochemical cycles. In
lake sediments, another mechanism for the formation of DMS by H2S methylation may be
important. The 34S/32S ratio (d34S values) of DMSP of marine surface water around the
globe is very homogeneous ranging between +18.9 o to +20.3 o and the fractionation
between DMSP and DMS is < +1 o (Amrani et al. 2013). The δ34S values of DMS
and other VOSC in sediments should be 34S depleted, similar to its H2S precursor
(Oduro et al., 2011). Our goal was to quantify the benthic DMS and DMSP emissions
from the sediments of warm monomictic Lake Kinneret relative to their formation
by surface water algae by using sulfur isotope ratios. Water column samples and
sediment samples from Lake Kinneret were purged and trap in order to extract
the VOSC and then introduced to a GC/MC-ICPMS for isotopic measurements
(Amrani et al. 2013). The δ34S of DMSP in the water and sediment columns of
Lake Kinneret a mesotrophic monomictic lake were measured. Our preliminary
results show δ34S values for DMSP ranged between +10.3 o and +13.4 o in the
water column. The sulfate δ34S values ranged between +12.6 o to +14.9 o. δ34S
–DMSP in the sediment column showed similar values between +9.4 o and +13.0
o, indicating a similar sulfur source. Similar δ34S values obtain for other VOSC
such as ethanethiol that contributes significantly to the VOSC of Lake Kinneret
sediments.
Amrani, A., W. Said-Ahmad,Y. Shaked, and R. P. Kiene. 2013. Sulfur isotopes
homogeneity of oceanic DMSP and DMS. PNAS 110(46):18413-18418.
Oduro, H., Kamyshny, A. Jr.,W. Guo, and J. Farquhar. 2011. Multiple sulfur isotopes
analysis of volatile organic sulfur compounds and their sulfonium precursors in marine
coastal environments. Marine Chemistry 124:78-89. |
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