Most of the anthropogenic radionuclide ¹²⁹I released to the marine environment from the nuclear fuel reprocessing plants (NFRP) at Sellafield (England) and La Hague (France) is transported to the Arctic Ocean via the North Atlantic Current and the Norwegian Coastal Current. ¹²⁹I concentrations in seawater provides a powerful and well-established radiotracer technique to provide information about the mechanisms which govern water mass transport in the Nordic Seas and the Arctic Ocean and is gaining importance when coupled with other tracers (e.g. CFC, ²³⁶U).

In this work, ¹²⁹I concentrations in surface and depth profiles from the Nordic Seas and the North Atlantic (NA) Ocean collected from four different cruises between 2011 and 2012 are presented. This work allowed us to i) update information on ¹²⁹I concentrations in these areas, required for the accurate use of ¹²⁹I as a tracer of water masses; and ii) investigate the formation of deep water currents in the eastern part of the Nordic Seas, by the analysis of ¹²⁹I concentrations and temperature-salinity (T-S) diagrams from locations within the Greenland Sea Gyre. In the Nordic Seas, ¹²⁹I concentrations in seawater are of the order of 10⁹ at·kg^− 1, one or two orders of magnitude higher than those measured at the NA Ocean, not so importantly affected by the releases from the NFRP. ¹²⁹I concentrations of the order of 10⁸ atoms·kg^− 1 at the Ellet Line and the PAP suggest a direct contribution from the NFRP in the NA Ocean.

An increase in the concentrations in the Nordic Seas between 2002 and 2012 has been detected, which agrees with the temporal evolution of the ¹²⁹I liquid discharges from the NFRPs in years prior to this. Finally, ¹²⁹I profile concentrations, ¹²⁹I inventories and T-S diagrams suggest that deep water formation occurred in the easternmost area of the Nordic Seas during 2012.

从英国塞拉菲尔德（Sellafield）和法国拉海牙（La Hague）的核燃料后处理厂（NFRP）向海洋环境释放的大多数人为放射性核素¹²⁹ I通过北大西洋洋流和挪威沿海洋流被输送到北冰洋。海水中的¹²⁹ I浓度提供了一种强大而完善的放射性示踪剂技术，可提供有关控制北欧海域和北冰洋水质运输机制的信息，与其他示踪剂（例如CFC，²³⁶ U）结合使用时，这一点正变得越来越重要。

在这项工作中，提出了从2011年至2012年之间四次航行中收集的来自北欧海和北大西洋（NA）海洋的地表和深度剖面中的¹²⁹ I浓度。这项工作使我们能够：i）更新这些区域中¹²⁹ I浓度的信息，这是准确使用¹²⁹ I作为水团示踪剂所必需的；ii）通过分析格陵兰海环流地区的¹²⁹ I浓度和温度-盐度（TS）图，研究了北欧海东部深水流的形成。在北欧海域，海水中的¹²⁹ I浓度约为10 ⁹ at·kg ^{− 1}，比北美海域的测量值高一个或两个数量级，而不受NFRP释放的影响不那么重要。Ellet线和PAP处的¹²⁹ I浓度约为10 ⁸ 原子·kg ^-1，表明NFRP在北大西洋中的直接贡献。

在2002年至2012年之间，北欧海中的浓度增加了，这与之前几年NFRPs排放的¹²⁹ I液体的时间演变是一致的。最后，¹²⁹ I剖面浓度，¹²⁹ I清单和TS图表明，2012年北欧海最东端发生了深水形成。