Isotopic fractionation during soil uptake of atmospheric hydrogen
Isotopic fractionation during soil uptake of atmospheric hydrogen
复制标题
土壤吸收大气氢过程中的同位素分馏
DOI：
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发表时间：
2010
期刊：
影响因子：
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通讯作者：
R. Gammon
中科院分区：
文献类型：
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作者：
A. Rice;A. Dayalu;P. Quay;R. Gammon
抽象的。在华盛顿西部次生林中，利用土壤室研究了土壤对大气氢（H2）的吸收及其氢同位素效应。在冬季和夏季都进行了室内研究，以解释土壤含水量（4-50%）和温度（6-22 °C）的大自然变化。H2沉积速度范围为0.01-0.06 cm s-1，平均值为0.033 ± 0.008 cm s-1（95%置信区间）。与以前的研究一致，沉积速度与土壤水分低于20%的土壤水分含量在夏季。在冬季，有相当大的变化，观察到沉积速度是不密切相关的土壤水分。氢动力学同位素效应与H2吸收的范围为−24‰至−109‰。对实验数据的综合分析得出平均KIE为−57 ± 5‰（95%CI）。KIE的一些变异性可以用较低（30%）土壤含水量下较大的同位素效应来解释。测得的KIE也被发现与沉积速度，发生在较高的沉积速度与较小的同位素效应。如果正确的话，这些发现将对大气测量的解释和H2 δD的建模产生影响。
Abstract. Soil uptake of atmospheric hydrogen (H2) and the associated hydrogen isotope effect were studied using soil chambers in a Western Washington second-growth coniferous forest. Chamber studies were conducted during both winter and summer seasons to account for large natural variability in soil moisture content (4–50%) and temperature (6–22 °C). H2 deposition velocities were found to range from 0.01–0.06 cm s−1 with an average of 0.033 ± 0.008 cm s−1 (95% confidence interval). Consistent with prior studies, deposition velocities were correlated with soil moisture below 20% soil moisture content during the summer season. During winter, there was considerable variability observed in deposition velocity that was not closely related to soil moisture. The hydrogen kinetic isotope effect with H2 uptake was found to range from −24‰ to −109‰. Aggregate analysis of experimental data results in an average KIE of −57 ± 5‰ (95% CI). Some of the variability in KIE can be explained by larger isotope effects at lower ( 30%) soil moisture contents. The measured KIE was also found to be correlated with deposition velocity, with smaller isotope effects occurring at higher deposition velocities. If correct, these findings will have an impact on the interpretation of atmospheric measurements and modeling of δD of H2.