Sources of SO₂, SO₄^2-, NO_x, and NO₃- in the Air of Four Spanish Remote Stations

In this study we have analyzed the sources of SO₂, SO₄^2-, No_x, and NO₃^- in the air of four remote Spanish stations belonging to the European Monitoring and Evaluation Programme (EMEP) network. Information about trajectories has been used together with the conditional probability functions (CPFs).¹ The most remarkable result is that the Mediterranean area is the main source of these pollutants in the air of the Spanish EMEP stations. Northern Africa and Central Europe are also important sources while the Atlantic Ocean and British Islands are, in general terms, low sources of these pollutants. The role of the Iberian Peninsula as a source of pollutants in one of the stations, Logrono, is analyzed with more details using smaller regions to define CPFs.