DOI: 10.5194/hess-23-3007-2019
论文题名: Continuous; near-real-time observations of water stable isotope ratios during rainfall and throughfall events
作者: Herbstritt B. ; Gralher B. ; Weiler M.
刊名: Hydrology and Earth System Sciences
ISSN: 1027-5606
出版年: 2019
卷: 23, 期: 7 起始页码: 3007
结束页码: 3019
语种: 英语
Scopus关键词: Catchments
; Light measurement
; Rain
; Continuous measurements
; Continuous observation
; High temporal resolution
; Meteorological measurements
; Meteorological station
; Meteorological variables
; Stable isotopes of water
; Water stable isotopes
; Isotopes
; catchment
; instrumentation
; interception
; isotopic composition
; isotopic ratio
; observational method
; rainfall
; real time
; spectrometer
; stable isotope
; throughfall
英文摘要: The water isotopic composition of throughfall is affected by complex diffusive exchange with ambient water vapour, evaporative enrichment of heavy isotopes, and mixing processes in the tree canopy. All interception processes occur simultaneously in space and time, generating a complex pattern of throughfall depth and water isotopic composition. This pattern ultimately cascades through the entire hydrologic system and is therefore crucial for isotope studies in catchment hydrology, where recharge areas are often forested, while reference meteorological stations are generally in the open. For the quasi real-time observation of the water isotopic composition (d18O and d2H) of both gross precipitation and throughfall, we developed an approach combining a membrane contactor (Membrana) with a laser-based Cavity Ring-Down Spectrometer (CRDS, Picarro), obtaining isotope readings every 2 s. A setup with two CRDS instruments in parallel analysing gross precipitation and throughfall simultaneously was used for the continuous observation of the temporal effect of interception processes on the stable isotopes of water. All devices were kept small to minimize dead volume with time lags of only 4 min for water from the rainfall collectors to the isotope analysers to increase the temporal resolution of isotope observations. Complementarily, meteorological variables were recorded at high temporal resolution at the same location. The achieved evolution from discrete liquid or event-based bulk samples to continuous measurements allows for direct comparison of water stable isotope data with common meteorological measurements. Future improvements of the spatial representativeness will make our approach an even more powerful tool towards detailed insight into the dynamic processes contributing to interception during rainfall events. © 2019 Author(s). Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/162934
Appears in Collections: 气候变化与战略
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作者单位: Herbstritt, B., Hydrology, Faculty of Environment and Natural Resources, Albert Ludwig University, Freiburg, 79098, Germany; Gralher, B., Hydrology, Faculty of Environment and Natural Resources, Albert Ludwig University, Freiburg, 79098, Germany; Weiler, M., Hydrology, Faculty of Environment and Natural Resources, Albert Ludwig University, Freiburg, 79098, Germany
Recommended Citation:
Herbstritt B.,Gralher B.,Weiler M.. Continuous; near-real-time observations of water stable isotope ratios during rainfall and throughfall events[J]. Hydrology and Earth System Sciences,2019-01-01,23(7)