This contribution describes the ocean biogeochemical component of the Geophysical Fluid Dynamics Laboratory's Earth System Model 4.1 (GFDL‐ESM4.1), assesses GFDL‐ESM4.1's capacity to capture observed ocean biogeochemical patterns, and documents its response to increasing atmospheric CO₂. Notable differences relative to the previous generation of GFDL ESM's include enhanced resolution of plankton food web dynamics, refined particle remineralization, and a larger number of exchanges of nutrients across Earth system components. During model spin‐up, the carbon drift rapidly fell below the 10 Pg C per century equilibration criterion established by the Coupled Climate‐Carbon Cycle Model Intercomparison Project (C4MIP). Simulations robustly captured large‐scale observed nutrient distributions, plankton dynamics, and characteristics of the biological pump. The model overexpressed phosphate limitation and open ocean hypoxia in some areas but still yielded realistic surface and deep carbon system properties, including cumulative carbon uptake since preindustrial times and over the last decades that is consistent with observation‐based estimates. The model's response to the direct and radiative effects of a 200% atmospheric CO₂ increase from preindustrial conditions (i.e., years 101–120 of a 1% CO₂ yr⁻¹ simulation) included (a) a weakened, shoaling organic carbon pump leading to a 38% reduction in the sinking flux at 2,000 m; (b) a two‐thirds reduction in the calcium carbonate pump that nonetheless generated only weak calcite compensation on century time‐scales; and, in contrast to previous GFDL ESMs, (c) a moderate reduction in global net primary production that was amplified at higher trophic levels. We conclude with a discussion of model limitations and priority developments.

中文翻译：

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GFDL地球系统模型4.1中的海洋生物地球化学及其对大气CO2升高的响应

该文稿描述了地球物理流体动力学实验室地球系统模型4.1（GFDL-ESM4.1）中的海洋生物地球化学成分，评估了GFDL-ESM4.1捕获观测到的海洋生物地球化学模式的能力，并记录了其对大气中CO ₂含量增加的响应。与上一代GFDL ESM相比，显着差异包括浮游生物食物网动力学的增强分辨率，精细的矿物质再矿化以及整个地球系统各组成部分的大量养分交换。在模型旋转过程中，碳漂移迅速降至低于气候-碳循环耦合模型比较项目（C4MIP）建立的每世纪10 Pg C的平衡标准以下。模拟功能强大地捕获了大规模观察到的养分分布，浮游生物动力学和生物泵的特征。该模型在某些地区过分表达了磷酸盐限制和开放性海洋缺氧，但仍产生了逼真的表面和深层碳系统特性，包括自工业化前以来和过去几十年的累积碳吸收量，这与基于观测的估计值一致。模型对200％大气CO的直接和辐射效应的响应₂从工业化前的条件（即1％CO ₂ yr ^-1模拟的101-120年）的增加包括：（a）弱化的浅滩有机碳泵，导致2,000 m处的下沉通量减少38％；（b）碳酸钙泵减少了三分之二，但仅在一个世纪的时间尺度上产生了微弱的方解石补偿；与（c）与以前的GFDL ESM相比，（c）全球净初级生产的适度下降，并在较高的营养水平下被放大。最后，我们讨论了模型的局限性和优先事项。