Development of the MIROC-ES2L Earth system model and the evaluation of biogeochemical processes and feedbacks
Development of the MIROC-ES2L Earth system model and the evaluation of biogeochemical processes and feedbacks
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DOI：
10.5194/gmd-13-2197-2020
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发表时间：
2020-05-13
影响因子：
5.1
通讯作者：
Kawamiya, Michio
中科院分区：
文献类型：
--
作者：
Hajima, Tomohiro;Watanabe, Michio;Kawamiya, Michio
本文介绍了新的地球系统模式（ESM），气候跨学科研究模式，长期模拟地球系统版本2（MIROC-ES 2L），使用最先进的气候模式作为物理核心。该模型嵌入了一个明确的碳-氮相互作用的陆地生态地球化学成分来解释土壤养分对植物生长和陆地碳汇的控制。该模型的海洋生物地球化学成分进行了很大程度的更新，以模拟碳、氮、磷、铁和氧的生物地球化学循环，以便海洋初级生产力可以受到多种营养限制的控制。海洋氮循环与陆地成分通过河流排放过程相耦合，并考虑了来自火成和成岩来源的铁的外部输入。历史模拟与观测研究的比较表明，该模式能够再现短暂的全球气候变化和碳循环，以及观测到的陆地碳循环和上层海洋地球化学的大尺度空间格局。该模型展示了历史上人类通过土地利用和农业对氮循环的扰动，并模拟了对陆地碳循环的影响。在前工业条件下的敏感性分析表明，模拟的海洋生物地球化学可以改变区域（和大幅度）从大气和河流的营养输入。基于一个理想化的实验，其中规定CO2以1% yr（-1）的速率增加，瞬态气候响应（TCR）估计为1.5 K，即，大约70%，从我们以前的ESM中使用的耦合模型相互比较项目第5阶段（CMIP 5）。由于陆地碳汇的增强，累积的空气传播分数（AF）也减少了15%，这导致空气传播分数接近CMIP 5 ESM的多模式平均值。瞬态气候对累积碳排放的响应（TCRE）为1.3KEGC（-1），即，比CMIP 5 ESM的平均值略小，这表明该模型将对未来气候做出“乐观”的预测。该模型和仿真结果有助于CMIP 6。MIROC-ES 2L可以进一步提高我们对气候-地球化学相互作用机制的理解，预测未来的环境变化，并通过以整体和互动的方式发展气候，地球化学和人类活动的过程来探索我们未来的可持续发展选择。
This article describes the new Earth system model (ESM), the Model for Interdisciplinary Research on Climate, Earth System version 2 for Long-term simulations (MIROC-ES2L), using a state-of-the-art climate model as the physical core. This model embeds a terrestrial biogeochemical component with explicit carbon-nitrogen interaction to account for soil nutrient control on plant growth and the land carbon sink. The model's ocean biogeochemical component is largely updated to simulate the biogeochemical cycles of carbon, nitrogen, phosphorus, iron, and oxygen such that oceanic primary productivity can be controlled by multiple nutrient limitations. The ocean nitrogen cycle is coupled with the land component via river discharge processes, and external inputs of iron from pyrogenic and lithogenic sources are considered. Comparison of a historical simulation with observation studies showed that the model could reproduce the transient global climate change and carbon cycle as well as the observed large-scale spatial patterns of the land carbon cycle and upper-ocean biogeochemistry. The model demonstrated historical human perturbation of the nitrogen cycle through land use and agriculture and simulated the resultant impact on the terrestrial carbon cycle. Sensitivity analyses under preindustrial conditions revealed that the simulated ocean biogeochemistry could be altered regionally (and substantially) by nutrient input from the atmosphere and rivers. Based on an idealized experiment in which CO2 was prescribed to increase at a rate of 1% yr(-1), the transient climate response (TCR) is estimated to be 1.5 K, i.e., approximately 70% of that from our previous ESM used in the Coupled Model Intercomparison Project Phase 5 (CMIP5). The cumulative airborne fraction (AF) is also reduced by 15% because of the intensified land carbon sink, which results in an airborne fraction close to the multimodel mean of the CMIP5 ESMs. The transient climate response to cumulative carbon emissions (TCRE) is 1.3KEgC(-1), i.e., slightly smaller than the average of the CMIP5 ESMs, which suggests that "optimistic" future climate projections will be made by the model. This model and the simulation results contribute to CMIP6. The MIROC-ES2L could further improve our understanding of climate-biogeochemical interaction mechanisms, projections of future environmental changes, and exploration of our future options regarding sustainable development by evolving the processes of climate, biogeochemistry, and human activities in a holistic and interactive manner.