The naturally occurring ²¹⁰Po (t_1/2 = 138.3d) and ²¹⁰Pb (t_1/2 = 22.3 y) radionuclide pair has been extensively used to study particle scavenging, cycling and transport in the ocean. However, the role of particle composition in the scavenging, sorption and fractionation of ²¹⁰Po²¹⁰Pb needs to be better understood to successfully utilize these radionuclides as oceanographic tracers. Here, we measure dissolved and particulate ²¹⁰Pb and ²¹⁰Po activities for both small (1-51 μm) and large particles (> 51 μm) with abundance of major phases of suspended particulate matter (SPM) from the US GEOTRACES Arctic transect to examine the role of the concentration and composition of SPM in scavenging and fractionation of these radionuclides along the coastal, Canada Basin and interior stations. ²¹⁰Po²¹⁰Pb disequilibria were observed throughout the water column for all stations. The Pacific end member had the highest activity of ²¹⁰Po and ²¹⁰Pb in dissolved samples. The calculated partition coefficients (K_d) of ²¹⁰Po and ²¹⁰Pb varied between 3.2 × 10⁵ to 9.9 × 10⁸ L kg⁻¹ and 7.9 × 10⁵ to 6.9 × 10⁸ L kg⁻¹ respectively and followed a log-linear trend with SPM for particle size fractions. Principal Component Analysis (PCA) and correlation analysis for six major particle phases indicated a significant positive correlation between ²¹⁰Pb and the lithogenic phase. Both ²¹⁰Po and ²¹⁰Pb had significant negative correlations with opal. Our results suggest that particle composition alone cannot explain the observed variability in K_d across the different oceanic regime along the transect. Estimated K_d values from an end member mixing model were found to be within the range of observed K_d values and suggest that higher particulate Mn concentration in the Arctic may be partly responsible for the higher K_d observed in the basin compared to Atlantic and Pacific.

天然存在的²¹⁰ Po（t _1/2  = 138.3d）和²¹⁰ Pb（t _1/2  = 22.3 y）放射性核对已被广泛用于研究海洋中的粒子清除，循环和运输。但是，要成功地利用这些放射性核素作为海洋示踪剂，需要更好地理解颗粒成分在²¹⁰ Po ²¹⁰ Pb的清除，吸附和分馏中的作用。在这里，我们测量溶解的和颗粒的²¹⁰ Pb和²¹⁰来自美国GEOTRACES北极样带的大量主要相的悬浮颗粒物（SPM）的小颗粒（1-51μm）和大颗粒（> 51μm）的Po活性，以研究SPM的浓度和组成在清除中的作用这些放射性核素沿沿海，加拿大盆地和内陆站的分离。在所有站的整个水柱中均观察到²¹⁰ Po ²¹⁰ Pb不平衡。在溶解的样品中，太平洋末端成员的活性最高，为²¹⁰ Po和²¹⁰ Pb。计算出的²¹⁰ Po和²¹⁰ Pb的分配系数（K _d）在3.2×10 ⁵至9.9×10 ^{8之间变化} 分别为L kg ^-1和7.9×10 ⁵至6.9×10 ⁸  L kg ^-1，并且对于颗粒大小分数，SPM呈对数线性趋势。对六个主要粒子相的主成分分析（PCA）和相关性分析表明，²¹⁰ Pb与成岩相之间存在显着的正相关。两个²¹⁰蒲和²¹⁰铅曾与蛋白石显著负相关。我们的结果表明，仅颗粒成分不能解释沿横断面不同海洋模式中K _d的观测变异性。估计K _d最终成员混合模型的_Kd值在观测到的K _d值范围内，表明与大西洋和太平洋地区相比，北极地区较高的Mn颗粒物浓度可能是盆地中观测到的K _d较高的部分原因。