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| Titel |
Impact of elevation and weather patterns on the isotopic composition of precipitation in a tropical montane rainforest |
| VerfasserIn |
D. Windhorst, T. Waltz, E. Timbe, H.-G. Frede, L. Breuer |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1027-5606
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| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 17, no. 1 ; Nr. 17, no. 1 (2013-01-31), S.409-419 |
| Datensatznummer |
250017699
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| Publikation (Nr.) |
 copernicus.org/hess-17-409-2013.pdf |
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| Zusammenfassung |
This study presents the spatial and temporal variability of
δ18O and δ2H isotope signatures in precipitation of a
south Ecuadorian montane cloud forest catchment (San Francisco catchment).
From 2 September to 25 December 2010, event sampling of open rainfall was
conducted along an altitudinal transect (1800 to 2800 m a.s.l.) to
investigate possible effects of altitude and weather conditions on the
isotope signature.
The spatial variability is mainly affected by the altitude effect. The event
based δ18O altitude effect for the study area averages
−0.22‰ × 100 m−1 (δ2H:
−1.12‰ × 100 m−1). The temporal
variability is mostly controlled by prevailing air masses. Precipitation
during the times of prevailing southeasterly trade winds is significantly
enriched in heavy isotopes compared to precipitation during other weather
conditions. In the study area, weather during austral winter is commonly
controlled by southeasterly trade winds. Since the Amazon Basin contributes
large amounts of recycled moisture to these air masses, trade wind-related
precipitation is enriched in heavy isotopes. We used deuterium excess to
further evaluate the contribution of recycled moisture to precipitation.
Analogously to the δ18O and δ2H values, deuterium
excess is significantly higher in trade wind-related precipitation.
Consequently, it is assumed that evaporated moisture is responsible for high
concentrations of heavy isotopes during austral winter. |
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