We investigated seasonal net community production (NCP) variations in the productive Amundsen Sea Polynya, integrating observational data and ecosystem modeling. NCP estimates (NCP_O2/Ar) from in situ O₂/Ar data during the austral summer (January-March) from 2011 to 2018 were compared with those from a one-dimensional ecosystem model. Early January saw the highest NCP_O2/Ar values ranging from 115 to 139 mmol O₂ m⁻² d⁻¹ among observations. Over the summer, NCP_O2/Ar gradually decreased, reaching 40 mmol O₂ m⁻² d⁻¹ by late February. Late summer values, though one-third of early January, remained notably positive, indicating net autotrophy. This persisted despite sea surface temperature dropping from >−0.4°C in January to −1.33°C in late February. Refining NCP_O2/Ar, we modified bacterial dynamics in our ecosystem model. Significantly improved model performance resulted from two key modifications. First, we introduced bacterial uptake dependency on Phaeocystis primary production. Second, we heightened temperature-dependent bacterial respiration and production approximately fifteenfold. These changes revealed NCP's remarkable sensitivity to minor temperature fluctuations (<1°C). Furthermore, modified bacterial dynamics delayed the net primary production peak by 2 weeks, underlining the importance of phytoplankton-bacteria interaction in the ocean carbon cycle. Model results estimated annual NCP in the Amundsen Sea Polynya at 4.04 mol C m⁻², aligning with summer NCP estimates (0.2–5.9 mol C m⁻²) in observational study. Our study advances NCP understanding in polar regions, emphasizing comprehensive observations, including bacterial processes, for understanding intricate biotic interactions. These findings align with past observations on bacterial metabolism and Phaeocystis ecological properties in the Antarctic oceans.

中文翻译：

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模型研究揭示了细菌过程在阿蒙森海冰间湖净群落生产中的关键作用

我们整合了观测数据和生态系统模型，研究了阿蒙森海冰间湖的季节性净群落生产（NCP）变化。将2011年至2018年南方夏季（1月至3月）原位O ₂ /Ar数据的NCP估计值（NCP _O2 /Ar ）与一维生态系统模型的估计值进行比较。 1 月初，观测中 NCP _O2/Ar值最高，范围为 115 至 139 mmol O ₂ m ^-2  d ^-1。整个夏季，NCP _O2/Ar逐渐下降，到2月底达到40 mmol O ₂ m ^-2  d ^-1 。夏末的数值虽然是一月初的三分之一，但仍显着为正值，表明净自养。尽管海面温度从 1 月份的 >−0.4°C 下降到 2 月底的−1.33°C，但这种情况仍然存在。通过精炼 NCP _O2/Ar，我们修改了生态系统模型中的细菌动力学。两项关键修改显着提高了模型性能。首先，我们介绍了细菌摄取对棕囊藻初级生产的依赖性。其次，我们将依赖温度的细菌呼吸和生产提高了大约十五倍。这些变化揭示了 NCP 对微小温度波动 (<1°C) 的显着敏感性。此外，改变的细菌动力学使净初级生产峰值延迟了两周，强调了浮游植物-细菌相互作用在海洋碳循环中的重要性。模型结果估计阿蒙森海冰间湖的年度 NCP 为 4.04 mol C m ⁻²，与观测研究中夏季 NCP 估计值（0.2–5.9 mol C m ⁻²）一致。我们的研究增进了对极地地区 NCP 的理解，强调全面观察，包括细菌过程，以了解复杂的生物相互作用。这些发现与过去对南极海洋细菌代谢和棕囊藻生态特性的观察结果一致。