Calculations of lead pollution levels for Croatia was carried out with resolution 50x50 km on the base of the official EMEP emission data and with resolution 10x10 km using emissions submitted by national experts. To perform modelling with high resolution emissions from neighbouring countries were re-gridded from 50-km grid to 10-km gridcells.
Emissions of lead in Croatia in 2007 officially submitted with 50-km resolution (left) and prepared in the framework of the Case Study with 10-km resolution (right). Location of measurement stations is indicated by blue stars (Croatia) and white triangles (EMEP)
Model simulations of lead pollution levels were carried out with resolutions 50x50 and 10x10 km. Maps with 10-km resolution were more detailed compared to those with 50-km resolution
Calculated concentrations of Pb in air (top row) and total deposition (bottom row) in Croatia in 2007 with resolution 50x50 km (left column) and 10x10 km (right column) resolution
Monitoring data on concentrations in air is provided for three Croatian stations: Zagreb, Sisak and Rijeka. Since these stations are urban, the measurements at these stations should be used in the pollution level analysis with some caution because they could be not representative even for modelling with 10-km resolution. To overcome this difficulty the data from EMEP stations (Ilmitz in Austria and Iskbra in Slovenia) located in the modelling domain were also involved. Changes of resolution from 50x50 km to 10x10 km resulted in improvements at some stations (Rijeka, Ilmitz, Sisak), but increased discrepancies between modelled and measured values at other sites (Zagreb, Iskbra).
One of factors responsible for Pb levels in air is wind re-suspension of lead which had been accumulated in top soils for decades. On annual level the contribution of wind re-suspension to calculated concentrations in air was significant. It varied from 40% to almost 90%. Modification of parameterization of this process is now ongoing. More details are available in EMEP status reports and MSC-E technical reports.
Modelled and measured concentrations of Pb
Observed and modelled (10x10km) annual