A 1-Dimensional Ice-Pelagic-Benthic transport model (IPBM) v0.1: Coupled simulation of ice, water column, and sediment biogeochemistry

Abstract. Aquatic biogeochemical processes can strongly interact, especially in polar regions, with processes occurring in adjacent ice and sediment layers, yet there are few modelling tools to simulate these systems in a fully coupled manner. We developed a 1-Dimensional Ice-Pelagic-Benthic transport model (IPBM) for coupled simulation of ice, water column, and upper sediment biogeochemistry. IPBM describes the processes of diffusion and particle sinking in both ice and water, as well sedimentation and bioturbation processes in the sediments. To describe ice, pelagic, and benthic biogeochemical dynamics (reaction terms), IPBM was partly coupled to the European Regional Seas Ecosystem Model (ERSEM) and partly to the Bottom RedOx Model biogeochemistry module (BROM-biogeochemistry) using the Framework for Aquatic Biogeochemical Models (FABM). To test the coupled system, hydrophysical forcing for a site in the Kara Sea area from a Regional Oceanic Modeling System (ROMS) simulation was used. The test run showed reasonable results for all main variables. IPBM reproduces the ice algae bloom in July followed by a pelagic phytoplankton bloom in August–September, as well as seasonal variability of nutrients in the water column.