Fjords on the west coast of Spitsbergen experience variable Arctic and Atlantic climate signals that drive seasonal and inter‐annual variability of phytoplankton productivity and composition, by mechanisms that are not fully resolved. To this end, a time series (2013–2018) of Kongsfjorden (N 78°54.2, E 11°54.0) phytoplankton pigments, ocean physics, nutrient concentrations, and microbial abundances was investigated. Kongsfjorden phytoplankton dynamics were predominantly governed by solar radiation and cycles of warming and freshwater discharge that caused pronounced changes in light and nutrient availability. Phytoplankton growth after the polar night commenced in March in a mixed, nutrient loaded water column, and accelerated in April after weak thermal stratification. Spring (weeks 10–22) showed high diatom relative abundance that ceased when silicic acid and nitrate reached limiting concentrations. Summer (weeks 23–35) was characterized by sixfold stronger stratification due to increased freshwater discharge and continued ocean heating. This caused a warm, low salinity surface layer with low nutrient concentrations. Small and diverse flagellates, together with high bacterial and viral abundances, thrived in this regenerative, N or P‐limited system. Elevated late summer chlorophyll a (Chl a), and ammonium suggested increased regeneration and nutrient pulses by glacial upwelling. Fall (weeks 36–48) caused rapidly declining Chl a and increasing diatom relative abundance, which persisted throughout the polar night, causing high diatom relative abundance during spring. Despite inter‐annual variability in ocean temperature and salinity we observed relatively stable seasonal phytoplankton taxonomic composition and Chl a.

中文翻译：

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北极高峡湾（Kongsfjorden，Spitsbergen）中变暖和淡水排放中的太阳辐射和太阳辐射驱动的循环控制季节和年际浮游植物的叶绿素a和分类学组成。

斯匹次卑尔根（Spitsbergen）西海岸的峡湾经历了北极和大西洋的气候信号变化，这些信号通过未完全解决的机制驱动浮游植物生产力和组成的季节性和年际变化。为此，研究了Kongsfjorden（N 78°54.2，E 11°54.0）浮游植物色素，海洋物理学，养分浓度和微生物丰度的时间序列（2013-2018）。Kongsfjorden浮游植物的动态主要受太阳辐射以及变暖和淡水排放的周期的控制，这导致光和养分利用率的显着变化。极地之夜之后的浮游植物生长于3月开始，在一个装有营养物质的混合水柱中进行，并在4月经过较弱的热分层而加速。春季（第10-22周）显示出较高的硅藻相对丰度，而当硅酸和硝酸盐达到极限浓度时，硅藻相对丰度就停止了。夏季（第23-35周）的特征是由于增加的淡水排放和持续的海洋加热，分层强度提高了六倍。这导致了温暖，低盐度的表层，营养成分浓度低。在这种再生，N或P限制的系统中，小型且多样的鞭毛以及高细菌和病毒丰富性。夏末叶绿素升高 在这种再生，氮或磷限制的系统中，细菌和病毒的丰度很高。夏末叶绿素升高 在这种再生，氮或磷限制的系统中，细菌和病毒的丰度很高。夏末叶绿素升高a（Chl a），而铵盐则表明由于冰川上升而增加了再生和养分脉冲。造成秋季（36-48周）迅速下降叶绿素一，增加硅藻相对丰富，其始终坚持的极夜，春运期间引起高硅藻相对丰度。尽管海洋温度和盐度年际变化，我们仍观察到相对稳定的季节性浮游植物分类学组成和叶绿素a。