Model simulations of the atmospheric trace metals concentrations and depositions over the Baltic Sea

The results of application of two nested Eulerian atmospheric transport models for investigation of airborne heavy metal pollution are presented. The distribution and deposition over Europe and Baltic Sea region were simulated for Pb, Cd and Zn for 2 two-months periods: June–July 1997 and February–March 1998. The European-wide calculations were made with the ADOM model from the GKSS Research Centre, and the Baltic regional calculations were made with the HILATAR model from the Finnish Meteorological Institute. The one-way 3-D nesting was used: hourly concentrations from the ADOM model were used by the HILATAR as vertically resolved boundary conditions. Input data for both models were taken from the weather forecast model HIRLAM and UBA/TNO emission inventory. This allows interpreting of some diversity in the calculation results in terms of different internal parameterization and spatial resolution of the models. Simulation results were compared with high-resolution atmospheric measurements carried out at four stations in the southern part of the Baltic Sea for the same period. Manifesting quite good agreement with observations, the models missed several high deposition events of Cd observed at coastal station Hel. Study of this phenomenon enabled to build a 2-D probability function for potential location of the unknown Cd source.