Posts tagged palmod
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).
VILMA (Viscoelastic Lithosphere and Mantle model)
- 29 May 2024
Volker Klemann and Maik Thomas
The topic of spectral finite-element code VILMA is the reduction of global GRACE, GPS and altimetry data with respect to the glacial-isostatic adjustment applying a 3D viscoelastic earth model. The model calculates the deformation of a viscoelastic and gravitating continuum in spherical domain, where lateral viscosity variations can be considered. Loading is prescribed as ice and ocean mass changes, which are determined consistently with respect to mass conservation, geoid changes and shoreline displacements by the sea-level equation. Code solves field equations of a spherical self-gravitating incompressible 3D-viscoelastic sphere with spectral–finite elements (Martinec 2000). GRD, that is rotational feedback and sea-level equation are solved for (Klemann et al. 2024 in prep.). Output are time-dependent changes in sea level, surface deformation and gravity potential in response to surface mass distribution. It is already coupled offline to PISM (Albrecht et al. 2024 in revision), MPI-ESM and AWI ESM and as compiled module in CLIMBER-X (Willeit et al. 2022). Offline coupling is implemented as exchange of two fields (in: ice load distribution; out: relative sea level).
ESM-Tools
- 22 May 2024
ESM-Tools is a modular software infrastructure that allows for seamlessly building, configuration and running of Earth System Models across different High Performance Computing (HPC) platforms (DKRZ-Levante, Jülich-Juwels, HLRN-4’s Lise and Emmy, ECMWF-Atos, ICCP-Aleph, etc.).
REcoM - Regulated Ecosystem Model
- 21 May 2024
REcoM is a water column biogeochemistry and ecosystem model, which incorporates cycles of carbon, nutrients (nitrogen, iron, and silicon) and oxygen with varying intracellular stoichiometry in phytoplankton, zooplankton, and detritus. REcoM can be run in configurations of varying complexity with up to three phytoplankton functional types (PFTs), namely diatoms, coccolithophores and small phytoplankton, up to three zooplankton types (micro- meso and polar microzooplankton) and up to two detritus classes (slow- and fast-sinking). REcoM can also simulate carbon and iron isotopes, and can be coupled to the sediment model Medusa. REcoM is the ocean biogeochemistry module of the AWI Earth System Model and is used for hindcasts, CMIP-type future projections and paleo applications.