Cloud water in windward and leeward mountain forests: The stable isotope signature of orographic cloud water
Cloud water in windward and leeward mountain forests: The stable isotope signature of orographic cloud water
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迎风和背风山林云水：地形云水的稳定同位素特征
DOI：
10.1029/2007wr006011
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发表时间：
2007
影响因子：
5.4
通讯作者：
L. Loope
中科院分区：
文献类型：
--
作者：
M. Scholl;T. Giambelluca;S. Gingerich;M. Nullet;L. Loope
云水可以是山地森林的重要水文输入。由于云水是一种易受气候变化影响的降水源，因此在流域和区域尺度上量化云水输入量非常重要。在这项研究中，云水和雨水样本收集每月在迎风和背风的东毛伊岛的网站2年。云水和雨水的体积加权平均同位素组成之差，迎风面为1.4‰ δ 18 O和12‰ δ 2 H，背风面为2.8‰ δ 18 O和25‰ δ 2 H，云水相对于雨水富集18 O和2 H。以往文献的总结表明，雾和/或云水是丰富的18 O和2 H相比，在世界各地的许多地方的雨，这项研究文件云水和雨的同位素组成所造成的天气模式常见的山区环境中的信风纬度。确定了每个站点的云水端元同位素组成，并将其用于同位素混合模型，以估计来自地形云的降水输入比例。地形云水输入在迎风面占总降水量的37%，在背风面占总降水量的46%。这是对森林水分输入的估计，可能会因全球气候变化或森林砍伐造成的云底高度变化而改变。
Cloud water can be a significant hydrologic input to mountain forests. Because it is a precipitation source that is vulnerable to climate change, it is important to quantify amounts of cloud water input at watershed and regional scales. During this study, cloud water and rain samples were collected monthly for 2 years at sites on windward and leeward East Maui. The difference in isotopic composition between volume‐weighted average cloud water and rain samples was 1.4‰ δ18O and 12‰ δ2H for the windward site and 2.8‰ δ18O and 25‰ δ2H for the leeward site, with the cloud water samples enriched in 18O and 2H relative to the rain samples. A summary of previous literature shows that fog and/or cloud water is enriched in 18O and 2H compared to rain at many locations around the world; this study documents cloud water and rain isotopic composition resulting from weather patterns common to montane environments in the trade wind latitudes. An end‐member isotopic composition for cloud water was identified for each site and was used in an isotopic mixing model to estimate the proportion of precipitation input from orographic clouds. Orographic cloud water input was 37% of the total precipitation at the windward site and 46% at the leeward site. This represents an estimate of water input to the forest that could be altered by changes in cloud base altitude resulting from global climate change or deforestation.