Modelling of Long-range Transport and Deposition of POPs in the European Region with Emphasis to Sea Currents

MSC-E Technical Note 5/2000

B.Strukov, Yu.Resnyansky, A.Zelenko, A.Gusev, V.Shatalov

ABSTRACT

This technical note presents the results of the work aimed at the further development of multi-compartment POP transport model for the EMEP region. The elaboration of this model on the basis of multi-compartment approach was initiated by EMEP/MSC-E several years ago. Its current stage is focused on one of the environmental media considered in the model, namely, the sea water compartment. The previous version of the model included a simplified description of exchange processes between the atmosphere and sea water, which was represented as a well mixed layer of a constant depth. There are a number of scientific studies confirming that oceans play a significant role in global cycling of some persistent organic pollutants (POPs) in the environment. The results of these investigations were used for the modification and refinement of ocean part of POP transport model. Modified model uses multi-layer vertical structure with 15 layers from top to bottom and considers pollutant transport with sea currents, turbulent diffusion, and air-sea exchange processes. Preliminary results obtained show that description of POP redistribution within sea water using the transport processes and turbulent diffusion leads to noticeable increase of POP accumulation in this compartment. These results reflect current understanding that oceans can be an essential storage medium for some of the POPs, e.g. PCBs. Modeling results were compared with observations of PCB concentrations in sea water. Comparison results show reasonable agreement of computed concentrations with available measurements.