A Survey and Comparison of Ocean Biogeochemistry Models in the natESM Initiative

Abstract

This paper presents a comprehensive survey of contemporary ocean biogeochemistry (OBGC) models within the natESM (National Earth System Modeling) initiative, conducted by the natESM Ocean Biogeochemistry Working Group. We systematically document nine OBGC models spanning diverse complexity levels and application domains — from specialized components addressing detailed processes like sediment diagenesis or oxygen dynamics to comprehensive ecosystem models with fish and macrobenthos, to mature Earth System Model components. Our survey covers four thematic categories: model identification and purpose, biogeochemical and ecosystem complexity (nutrient representations, functional groups, stoichiometry, greenhouse gases, oxygen dynamics, and food web structure), technical characteristics (modularity, coupling approaches, high-performance computing), and community aspects (licensing, accessibility, quality assessment). The models reveal substantial diversity in their treatment of key biogeochemical processes, reflecting both the breadth of scientific questions they address and different historical development trajectories. Model choice depends strongly on specific application contexts, and modularization emerges as the community's central opportunity for a coherent, shared biogeochemistry framework. This deposit archives the manuscript together with its supporting structured model survey, community questionnaire instrument and anonymized response summary, and analysis scripts. Funded by the German Federal Ministry of Education and Research (BMBF) under the natESM initiative, grant 01LK2107A.