Windhorst, D.; Waltz, T.; Timbe, E.; Frede, H. & Breuer, L. (2013): <b>Impact of elevation and weather patterns on the isotopic composition of precipitation in a tropical montane rainforest</b>. <i>Hydrol. Earth Syst. Sci.</i> <b>177</b>, 409-419.
Resource Description
Title:
Impact of elevation and weather patterns on the isotopic composition of precipitation in a tropical montane rainforest
FOR816dw ID:
1231
Publication Date:
2013-01-31
License and Usage Rights:
FOR816 data user agreement: www.tropicalmountainforest.org/dataagreement.do
email:
edison_timbe <at> yahoo.com
Victor Manuel Albornoz - Quinta Balzay
Universidad de Cuenca Cuenca
Ecuador
Individual:
Hans-Georg Frede
Contact:
email:
hans-georg.frede <at> umwelt.uni-giessen.de
Heinrich-Buff-Ring 26
Institute for Landscape Ecology and Resources Management
Justus-Liebig-University Gießen
35392 Gießen
Germany
Individual:
Lutz Breuer
Contact:
email:
lutz.breuer <at> umwelt.uni-giessen.de
Heinrich-Buff-Ring 26
Institute for Landscape Ecology and Resources Management
Justus-Liebig-University Gießen
35392 Gießen
Germany
Abstract:
This study presents the spatial and temporal variability of ?18O and ?2H 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.<br/>
<br/>
The spatial variability is mainly affected by the altitude effect. The event based ?18O altitude effect for the study area averages ?0.22‰ × 100 m?1 (?2H: ?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 ?18O and ?2H 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.<br/>
