Freshening leads to a three-decade trend of declining nutrients in the western Arctic Ocean

• Published in: Environmental Research Letters
• Main Authors: Zhuang, Yanpei, Jin, Haiyan, Cai, Wei-Jun, Li, Hongliang, Jin, Meibing, Qi, Di, Chen, Jianfang
• Other Authors: National Natural Science Foundation of China
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: IOP Publishing 2021
• Subjects: Arctic; Arctic Ocean; Sea ice
• Online Access: http://dx.doi.org/10.1088/1748-9326/abf58b; https://iopscience.iop.org/article/10.1088/1748-9326/abf58b; https://iopscience.iop.org/article/10.1088/1748-9326/abf58b/pdf

Abstract Rapid warming and sea-ice loss in the Arctic Ocean are among the most profound climatic changes to have occurred in recent decades on Earth. Arctic Ocean biological production appears that it may be increasing as a result, but the consequences for nutrient concentrations are unknown. We have assembled a collection of historical field data showing that average concentrations of the macronutrients nitrate and phosphate have decreased by 79% and 29%, respectively, in surface waters of the western Arctic Ocean basin over the past three decades. The field observations and results from numerical ocean simulations suggest that this long-term trend toward more oligotrophic (nutrient-poor) conditions is driven primarily by the compound effects of sea-ice loss: a reduced resupply of nutrients from subsurface waters (due to fresh water addition and stronger upper-ocean stratification) coincident with increased biological consumption of nutrients (due to the greater availability of light needed for photosynthesis).