Using the radium quartet (228Ra, 226Ra, 224Ra, and 223Ra) to estimate water mixing and radium inputs in Loch Etive, Scotland
Using the radium quartet (228Ra, 226Ra, 224Ra, and 223Ra) to estimate water mixing and radium inputs in Loch Etive, Scotland
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使用镭四重奏（228Ra、226Ra、224Ra 和 223Ra）来估计苏格兰埃蒂夫湖的水混合和镭输入
DOI：
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
G. Henderson
中科院分区：
文献类型：
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作者：
Y. Hsieh;W. Geibert;P. Van;H. Stahl;D. Aleynik;G. Henderson
苏格兰峡湾的Loch Etive研究了Ra(Ra)四重态(228Ra、226Ra、224Ra和223Ra)，以提供对水混合速率和沉积物中Ra输入的新限制。由过量223Ra(223Raex)确定的入海口5m水层的最大输移率表明，这些水以不超过2.4±0.2 cm的S−1网传播，如果不考虑水平混合，水从河口到湖头需要17±2d。或者，忽略平流，短暂的Ra分布可以用6.1x106cm2 S−1(223Raex)或9.1x106cm2 S−1(224Raex)的水平混合率来解释。周期翻转环流在内湖孤立深盆化学循环的重新启动中起着重要作用。这个深盆地中的沉积物为孤立的深水提供了228Ra的主要输入，而228Ra在深水中的积累使人们能够评估228Ra的沉积通量，这是全球海洋228Ra输入的一个较差的限制方面。计算的内深盆地沉积228Ra通量为2.1±0.2(×10 9)个原子m−2yr−1，与以前从陆架沉积物测量的沉积228Ra输入相当，支持现有的全球228Ra预算，这些预算用于评估全球向海洋排放地下水的速率。
The radium (Ra) quartet (228Ra, 226Ra, 224Ra, and 223Ra) has been investigated in Loch Etive, a Scottish fjord, to provide new constraints on water mixing rates and on the inputs of Ra from sediments. Maximum water transport rates for the inflowing estuarine layer at 5 m depth, determined from the excess 223Ra (223Raex), indicate that this water travels at no more than 2.4 ± 0.2 cm s−1 net and that it takes 17 ± 2 d for waters to travel from the mouth to the head of the loch if no horizontal mixing is taken into account. Alternatively, neglecting advection, the short‐lived Ra distribution could be explained by horizontal mixing rates of 6.1 × 106 cm2 s−1 (223Raex) or 9.1 × 106 cm2 s−1 (224Raex). Periodic overturning circulation plays an important role in resetting chemical cycles in the isolated deep basin of the inner loch. Sediment in this deep basin provides the major input of 228Ra to the isolated deep water, and the accumulation of 228Ra in deep waters allows an assessment of sedimentary fluxes of 228Ra, a poorly constrained aspect of the 228Ra input to the global ocean. The calculated sedimentary 228Ra flux of 2.1 ± 0.2 (× 109) atoms m−2 yr−1 in the inner deep basin is comparable with previous measurements of sedimentary 228Ra inputs from shelf sediments, supporting existing global 228Ra budgets, which are used to assess global rates of groundwater discharge to the ocean.