Abstract Over the last decades, the western Arctic Ocean has undergone unprecedented environmental changes. However, long-term in situ observations of marine phytoplankton are still rare and therefore insufficient to fully characterize their evolutionary trends. This study investigated the diatom fluxes and composition in sediment trap material collected from the Northwind Ridge, western Arctic Ocean, from August 2008 to September 2009. Our data showed that Chaetoceros resting spores were the predominant species, accounting for >40% of the diatom composition. The sea ice diatom group, which included Fossula arctica, Fragilariopsis cylindrus and F. oceanica, dominated the rest of the assemblage throughout the observation period. While diatom fluxes in winter were extremely low, higher flux values were found in summer, and summer 2009 flux values were twice as high as those in 2008. The high total mass and diatom fluxes in summer 2009 were attributed to the combined effect of a weakened Beaufort Gyre, a strengthened Pacific water inflow (PWI) and the distribution pattern of the sea ice. The higher levels of coastal diatoms and terrigenous proxies in summer 2009 were consistent with the intensified PWI. Sea ice diatoms and sea ice biomarker IP25 fluxes were both high during the sea ice melting season and were significantly correlated with each other (r2 = 0.64, p

中文翻译：

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北冰洋西部北风岭上的硅藻组成和通量：海洋表面环流和海冰分布的影响

摘要 在过去的几十年里，北冰洋西部发生了前所未有的环境变化。然而，对海洋浮游植物的长期原位观察仍然很少见，因此不足以充分表征它们的进化趋势。本研究调查了 2008 年 8 月至 2009 年 9 月从北冰洋西部北风岭收集的沉积物捕集材料中的硅藻通量和组成。我们的数据显示，角毛藻静止孢子是主要物种，占硅藻组成的 40% 以上. 海冰硅藻群，包括 Fossula arctica、Fragilariopsis cylindrus 和 F. oceanica，在整个观察期间主导了其余的组合。虽然冬季硅藻通量极低，但夏季发现更高的通量值，和 2009 年夏季的通量值是 2008 年的两倍。 2009 年夏季的高总质量和硅藻通量归因于波弗特环流减弱、太平洋进水量 (PWI) 增强以及海冰。2009 年夏季沿海硅藻和陆源替代物水平较高，这与 PWI 的加剧一致。海冰硅藻和海冰生物标志物 IP25 通量在海冰融化季节都很高，并且彼此显着相关（r2 = 0.64，p 2009 年夏季沿海硅藻和陆源替代物水平较高，这与 PWI 的加剧一致。海冰硅藻和海冰生物标志物 IP25 通量在海冰融化季节都很高，并且彼此显着相关（r2 = 0.64，p 2009 年夏季沿海硅藻和陆源替代物水平较高，这与 PWI 的加剧一致。海冰硅藻和海冰生物标志物 IP25 通量在海冰融化季节都很高，并且彼此显着相关（r2 = 0.64，p