Distributions of total and size-fractionated particulate 210Po and 210Pb activities along the North Atlantic GEOTRACES GA01 transect: GEOVIDE cruise

التفاصيل البيبلوغرافية
العنوان: Distributions of total and size-fractionated particulate 210Po and 210Pb activities along the North Atlantic GEOTRACES GA01 transect: GEOVIDE cruise
المؤلفون: Gillian Stewart, Nolwenn Lemaitre, Maxi Castrillejo, Yi Tang, Montserrat Roca-Martí, Pere Masqué
المصدر: Biogeosciences. 15:5437-5453
بيانات النشر: Copernicus GmbH, 2018.
سنة النشر: 2018
مصطلحات موضوعية: 0106 biological sciences, Radionuclide, 010504 meteorology & atmospheric sciences, Mesopelagic zone, 010604 marine biology & hydrobiology, Geotraces, chemistry.chemical_element, Particulates, 01 natural sciences, Water column, chemistry, 13. Climate action, Environmental chemistry, Environmental science, Transect, Surface water, Ecology, Evolution, Behavior and Systematics, 0105 earth and related environmental sciences, Earth-Surface Processes, Polonium
الوصف: Vertical distributions of total and particulate polonium-210 (210Po) and lead-210 (210Pb) activities in the water column were measured at 11 stations in the North Atlantic during the GEOTRACES GA01 transect: GEOVIDE cruise in May–June 2014. Total 210Po activity was on average 24 % lower than 210Pb activity in the upper 100 m, and it was closer to unity in the mesopelagic (100–1000 m). The partitioning coefficients (Kd) along the transect suggest the preferential association of 210Po relative to 210Pb onto particles. The prominent role of small particles in sorption was confirmed by the observation that over 80 % of the particulate radionuclide activity was on small particles. To account for the observed surface water 210Po ∕ 210Pb disequilibria, particulate radionuclide activities and export of both small (1–53 µm) and large (>53 µm) particles must be considered. A comparison between the GEOVIDE total particulate 210Po ∕ 210Pb activity ratios (ARs) and the ratios in previous studies revealed a distinct geographic distribution, with lower particulate ARs in the high-latitude North Atlantic (including this study) and Arctic in relation to all other samples. For the samples where apparent oxygen utilization (AOU) was calculated at the same depth and time as the 210Po ∕ 210Pb AR (40 stations including this study), there was a two-phase correlation between the total particulate AR and AOU, likely reflecting the nature of the particles and demonstrating the forces of remineralization and radionuclide decay from particles as they age.
تدمد: 1726-4189
DOI: 10.5194/bg-15-5437-2018
URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_________::11638e1b83d7ba07b18cee1e9729af7f
https://doi.org/10.5194/bg-15-5437-2018
Rights: OPEN
رقم الانضمام: edsair.doi...........11638e1b83d7ba07b18cee1e9729af7f
قاعدة البيانات: OpenAIRE
الوصف
تدمد:17264189
DOI:10.5194/bg-15-5437-2018