Posts tagged esm2025
HAMOCC - HAMburg Ocean Carbon Cycle
- 12 June 2024
Fatemeh Chegini, Tatiana Ilyina
The HAMburg Ocean Carbon Cycle (HAMOCC) model is the ocean biogeochemistry component in ICON and MPI-ESM (Ilyina et al., 2013). HAMOCC simulates at least 20 biogeochemical tracers in the water column, following an extended nutrient, phytoplankton, zooplankton, and detritus approach, also including dissolved organic matter, as described in Six and Maier-Reimer (1996). It also simulates the upper sediment by 12 biologically active layers and a burial layer to represent the dissolution and decomposition of inorganic and organic matter as well as the diffusion of pore water constituents. The co-limiting nutrients consist of phosphate, nitrate, silicate, and iron. A fixed stoichiometry for all organic compounds is assumed. Phytoplankton is represented by bulk phytoplankton and diazotrophs (nitrogen fixers). Particulate organic matter (POM) is produced by zooplankton grazing on bulk phytoplankton and enters the detritus pool. Export production is separated explicitly into CaCO3 and opal particles. The POM sinking speed can be assigned using one of the three implemented methods: constant speed, linearly increasing speed with depths below the euphotic zone (also known as the “Martin curve”; Martin et al., 1987) or calculated using the recently developed M4AGO scheme (Maerz et al., 2020). The remineralization of detritus throughout the water column is either aerobic (if seawater oxygen concentration >0.5 μmolL−1) or anaerobic by denitrification and sulfate reduction. The HAMOCC model as part of ICON and MPI-ESM and has been extensively evaluated and applied in previous single-model (e.g., Ilyina et al., 2013; Paulsen et al., 2017; Müller et al., 2018; Mauritsen et al., 2019; Maerz et al., 2020; Jungclaus et al. 2022, Hohenegger et al. 2022) and multi-model studies (e.g., Bopp et al., 2013; Kwiatkowski et al., 2020; Séférian et al., 2020).