DAR1 - An Easy to Use, Single-Box, Configuration of a Global Scale Biogeochemical Ecosystem Model

Global scale biogeochemical ocean models are key to understanding the mechanisms which drive elemental cycles and their links to marine ecosystems. However, these models are rarely straightforward to use and their complexity can make them difficult to interpret. Here, we aim to address this problem by developing DAR1 -- a single box configuration of the MIT Darwin model, which is itself a global scale biogeochemical ecosystem model designed for understanding the emergent patterns of global plankton distributions. Our configuration is packaged inside Docker and implemented in the Julia programming language. This helps make it both computationally efficient and straightforward to implement on any local machine, independent of hardware and operating system. It allows for the replication of field and laboratory experiments in a model ocean and the rapid comparison of global runs with local predictions. We provide three case studies: a framework for nutrient amendment bottle experiments; a test of steady state assumptions on plankton community structure at the global scale; and an exploration of the niche space of nitrogen-fixing plankton. Our method has the potential to facilitate broader direct testing of global model assumptions in the context of small-scale measurements. DAR1 will also allow observational and laboratory oceanographers to directly test their results against model predictions in a straightforward, easy to use, manner. ### Competing Interest Statement The authors have declared no competing interest.