engleski

A simple rain collector preventing water re-evaporation dedicated for delta18O and delta2H analysis of cumulative precipitation samples

A simple rainwater collector has been developed that allows virtually evaporation-free monthly rain sampling for subsequent water stable isotope analysis. It is designed for collecting composite monthly samples as required for global monitoring of the isotopic composition of precipitation, like the Global Network for Isotopes in Precipitation (GNIP) as operated jointly by the International Atomic Energy Agency (IAEA) and the World Meteorological Organisation (WMO). The new collector has the advantages to minimize necessary staff time for sampling by easy and fast changes of sample bottles, to avoid any need of oil for prevention of evaporation, to be cheap in construction, and to be easily installed and used in remote areas (unattended during on month). Tests performed at the IAEA have proven that water stored in the sampler for nearly one year did not suffer significantly from any evaporation effect. Further comparisons performed at GNIP sampling stations show excellent performance of the new collector with advantages over some conventional precipitation samplers. Slightly more negative delta-values in the new collector than in conventional sampler types could indicate lower evaporation effects.

Rain collector; precipitation; stable isotopes; evaporation; fractionation

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