Modeling marine biogenic aerosol precursors in the Arctic Ocean

• Main Authors: Zeising, Moritz, Hauck, Judith, Heinold, Bernd, Losa, Svetlana N., Thoms, Silke, Zeppenfeld, Sebastian, Bracher, Astrid
• Format: Conference Object
• Language: unknown
• Published: 2021
• Subjects: Arctic; Arctic Ocean; Phytoplankton; Sea ice; Zooplankton
• Online Access: https://epic.awi.de/id/eprint/54008/; https://hdl.handle.net/10013/epic.53ace1db-5d04-457b-8e67-6caaec0ac321

The climate radiative effect of Arctic clouds depends on the presence of liquid or ice as cloud phase, which, among other things, is determined by the abundance of aerosols acting as cloud condensation or ice nuclei. Biogenic aerosols originate from local phytoplankton production in leads or open water. Based on recent publications, we choose acidic polysaccharides (PCHO) and transparent exopolymer particles (TEP) as tracers for biogenic aerosol precursors in the upper ocean layer. We incorporate processes of algal PCHO excretion, PCHO aggregation into TEP, as well as TEP degradation into the ecosystem model REcoM2 coupled to the finite-volume sea ice ocean circulation model FESOM2 with a resolution up to 4 km in the Arctic realm. REcoM2 describes the biogeochemical processes with two functional phytoplankton and one zooplankton class. Especially the ascending and enrichment of TEP to the surface microlayer, but also sinking of larger aggregates, are processes, which will be considered for model improvement. We are aiming at reproducing TEP distribution and seasonality patterns in the Arctic Ocean over two decades. Evaluation of the model results will be done using in-situ measurements (FRAM, MOSAiC). Ultimately, the modeled aerosol precursors will be used as an important input in an accompanied project, in which the net aerosol radiative effects will be quantified with an atmospheric aerosol-climate model. This work is part of the DFG TR 172 Arctic Amplification.