Evaluation of carbonyl sulfide biosphere exchange in the Simple Biosphere Model (SiB4)

Abstract

The uptake of carbonyl sulfide (COS) by terrestrial plants is linked to photosynthetic uptake of CO2 by a shared diffusion pathway. Applying COS as a photosynthesis tracer in models requires an accurate representation of biosphere COS fluxes, but these models have not been extensively evaluated against field observations of COS fluxes. In this paper, the COS flux as simulated by the Simple Biosphere Model, version 4 (SiB4) is updated with the latest mechanistic insights and evaluated 35 with site observations from different biomes: one evergreen needleleaf forest, two deciduous broadleaf forests, three grasslands, and two crop fields spread over Europe and North America. To account for the effect of atmospheric COS mole https://doi.org/10.5194/bg-2021-192 Preprint. Discussion started: 26 July 2021 c © Author(s) 2021. CC BY 4.0 License.