Sensitivity analysis and evaluation of ICON performance for the simulation of long-range atmospheric transport of POPs

Persistent Organic Pollutants (POPs) from local and regional sources are often transported over long distances and constitute a severe environmental problem for decades to come. The increase of industrial production of chemical synthetic compounds for manufacturing and daily use products raised the environmental burden and human exposure of these pollutants, which often have toxic, carcinogenic, or endocrine properties. Therefore, it is necessary to identify major sources, pathways and sinks of POPs in order to estimate negative effects on humans.

In the presented study, we use a next generation atmospheric circulation model, the ICOsahedral Non-hydrostatic model (ICON), to investigate the long-range atmospheric transport of POPs. ICON is a global unstructured grid model in which we implemented transport of per- and poly-fluoroalkyl substances (PFAS) as a first step towards the full range of POPs. The necessary PFAS emission sources for our simulations are taken from a newly developed global PFAS emission inventory for different compartments. The presented study is part of the McMEE project – ‘Multi Compartment Modeling- from Emission to Exposure’ where also the marine transport and transformation of PFAS and other POPs is included and will be coupled to the atmospheric simulations. Thus, the atmospheric modeling aspect is crucial for our research, due to the long lifetime of these substances, since they can be transported by large-scale circulation to reach remote regions such as the Arctic.

Besides the implementation of PFAS transport into ICON, we tested different model configurations including physical schemes, simulation periods and spin-off times to identify a suitable setup that can be capable of representing the transport of pollutants from regional to large scales, and long periods. Based on the evaluated modeling chain and the sensitivity tests performed, further developments towards the simulation of atmospheric chemistry and transport of other POPs are planned. Finally, the atmospheric simulations will be coupled to marine simulations in the McMEE project to identify the exposure of humans and the environment with POPs in different compartments.