A new multisource and high‐frequency approach to measuring δ2H and δ18O in hydrological field studies
A new multisource and high‐frequency approach to measuring δ2H and δ18O in hydrological field studies
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水文现场研究中测量 δ2H 和 δ18O 的新多源高频方法
DOI：
10.1002/2013wr013743
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发表时间：
2013
影响因子：
5.4
通讯作者：
J. McDonnell
中科院分区：
文献类型：
--
作者：
L. Pangle;J. Klaus;E. Berman;Manish X. Gupta;J. McDonnell
在基于同位素的野外研究中，δ2H和δ18O的测量从根本上提高了我们对土壤和水源集水区水流和输送时间尺度的理解。然而，直到最近，技术上的限制限制了收集和分析水样的时间分辨率。我们介绍了一种新的样品采集系统，由四通道蠕动泵，定制流歧管和CTC lcal自动进样器组成，并与现场可部署的激光光谱仪（LGR LWIA）配对。我们的系统能够在多达四个水源中高频（亚小时）测量δ2H和δ18O。我们将该系统部署在美国oror Corvallis的一个现场，在那里我们测量了降水的δ2H和δ18O组成以及两台溶渗仪的排水。该系统以每34 min 1个样品的时间频率生成每个样品的降水和排水δ2H和δ18O时间序列，平均对应每个样品的降水或排水0.84、0.63和0.48 mm。与连续较长时间间隔取样相比，高频数据显示出更大的短期变异性。该系统和采样配置是通用的，可以根据每个源的特征传输时间以可变频率对多个水流进行采样。
Measurements of δ2H and δ18O in isotope‐based field studies have fundamentally improved our understanding of water flow and transport time scales in soils and headwater catchments. Until recently, however, technical constraints have limited the temporal resolution at which water samples could be collected and analyzed. We introduce a new sample acquisition system—consisting of a four‐channel peristaltic pump, custom flow manifold, and CTC LCPAL auto‐sampler—that is paired with a field‐deployable laser spectrometer (LGR LWIA). Our system enables high‐frequency (subhourly) measurement of δ2H and δ18O in as many as four water sources. We deployed the system at a field site in Corvallis, OR, USA, where we measured the δ2H and δ18O composition of precipitation and the drainage from two lysimeters. The system produced δ2H and δ18O time series for precipitation and drainage from each lysimeter at a temporal frequency of one sample every 34 min, which, on average, corresponded to 0.84, 0.63, and 0.48 mm of precipitation or lysimeter drainage per sample. The high‐frequency data showed substantially greater short‐term variability than observed when sampling at successively longer time intervals. The system and sampling configuration are versatile and can be adapted to sample multiple water flows at variable frequencies depending on the characteristic transit times of each source.
影响因子：
6.3
作者：
Klaus, J.;Zehe, E.;McDonnell, J. J.
通讯作者：
McDonnell, J. J.