Comparison of spatial rainfall data calculated with a meteorological model and from interpolation of measurements - implications for FRAME modelled wet deposition

This work quantifies the differences between the two sources of spatial information of precipitation on FRAME modelled wet deposition of oxidised sulphur (SOx), nitrogen (NOy) and reduced nitrogen (NHx) for two years in an area of Poland. The model was run twice, first with precipitation dataset calculated with the WRF model (pWRF). The second run was based on interpolation of measured precipitation with kriging (pOK). SOx, NOy and NHx wet deposition calculated with pWRF precipitation gives lower country mean values if compared with pOK. The maximum values are higher for pWRF precipitation. Grid to grid correlation between pOK and pWRF modelled wet deposition is similar for both years, with the lowest values for NHx and the highest for SOx. The model-measurement agreement is better for the pOK FRAME run. The results show large uncertainties related with wet deposition modelling due to uncertainties in rainfall data.