The North Atlantic tritium and radiocarbon transients 1972–1983
The North Atlantic tritium and radiocarbon transients 1972–1983
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1972-1983 年北大西洋氚和放射性碳瞬变
DOI：
10.1029/jc095ic11p20147
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发表时间：
1990
影响因子：
--
通讯作者：
C. Rooth
中科院分区：
文献类型：
--
作者：
H. G. Östlund;C. Rooth
在北大西洋，在十年的时间尺度上，深层通风和水团的改造过程，说明了不断变化的分布模式的人为氚和放射性碳。从两个准天气调查的北大西洋内部，地球化学海洋部分研究（GEOSECS）和补充海洋观测项目在1972年，和瞬态示踪剂在海洋（TTO）在1981年和1983年，数据比较横截面和地图表示的条件大约一个和二十年后，第一次主要的示踪剂注入。讨论强调衰变校正的氚浓度场的比较，这表明几个不同的制度的瞬态演变，包括令人惊讶的恒定在一些区域模式的例子。虽然这些结果在很大程度上支持了以前关于运输模式的定性观点，但也表明，高纬度地区的深水注入模式在GEOSECS（1972年）前后或之后不久肯定发生了重大变化，涉及北大西洋上层深水供应量的大幅增加。近地表沃茨显示出强烈的热带（低氚）影响的迹象，在副热带环流的西南部和西部的副热带（低氚）影响，而东北部更多的是受到来自北极地表沃茨的持续氚输入的影响。强有力的证据，不同的子流域规模的内部循环域中发现的事实，主要分布制度的过渡中看到的GEOSECS数据再次观察到TTO，从而保持通过第二个十年的瞬态。«少
Deep ventilation and water mass transformation processes in the North Atlantic, on decadal time scales, are illustrated by the evolving distribution patterns of anthropogenic tritium and radiocarbon. Data from two quasi-synoptics surveys of the interior of the North Atlantic, the Geochemical Ocean Sections Study (GEOSECS) and complementary oceanographic observation projects in 1972, and the Transient Tracers in the Oceans (TTO) in 1981 and 1983, are presented in comparative cross sections and maps representing conditions roughly one and two decades, respectively, after the first major tracer injections. The discussion emphasizes comparisons of the decay-corrected tritium concentration fields, which show several distinct regimes of transient evolution, including examples of surprising constancy in some regional patterns. While largely supportive of previous qualitative ideas about transport patterns, these results also suggest that the patterns of deep water injection in high latitudes must have undergone a major change around or soon after the time of GEOSECS (1972), involving a major increase in supply of Upper North Atlantic Deep Water. The near-surface waters show strong signatures of tropical (low tritium) influence in the southwestern and western part of the subtropical (low tritium) influence in the southwestern and western part of the subtropical gyre, while the northeasternmore » part is influenced by continued tritium input from Arctic surface waters. Strong evidence for distinct sub-basin-scale interior circulation domains is found in the fact that the major distribution regime transitions seen in the GEOSECS data are observed again in TTO, and thus maintained through the second decade of the transient.« less