Zahari Zlatev received his MSc from the Sofia University and his PhD from the Sct. Petersbourg University. He is a senior scientist and a project leader (Long-range Transport Modelling) at NERI (National Environmental Research Institute, Roskilde, Denmark) since 1980. He has developed the Unified Danish Eulerian Model (UNI-DEM), which has been used in many environmental studies and scientific projects (see also http://www.dmu.dk/AtmosphericEnvironment/DEM). Zahari Zlatev published five monographs (two in Kluwer, two in Springer and one in MIR Publishers), has been editor of four proceedings volumes, has 92 papers in international journals, 123 papers in proceedings of international conferences and more than 200 institutional reports. He has been involved in training young specialists; including graduated students and PhD students. Zahari Zlatev organized five international conferences and nine mini-symposia at international conferences; in Stanford (USA), in Hamburg (Germany), in Varna (Bulgaria), in Toronto (Canada), three in Sozopol (Bulgaria), in Limassol (Cyprus), in Copenhagen (Denmark) and in San Francisco (USA). He has been an invited speaker at 24 international conferences and in the organizing committee of many international workshops and conferences (see also http://www.dmu.dk/AtmosphericEnvironment/zlatev.htm). Ivan Dimov received his MSc in 1976, PhD in 1980 and the Doctor of Sciences degree in 1984 in Moscow, Russia. He is professor in Mathematical modelling since 1996. From 1996 to 2004 he was director of the Institute for Parallel Processing of the Bulgarian Academy of Sciences and Head of the Bulgarian Information Society Center of Excellence BIS-21. Currently he is a research professor at the University of Reading, UK. Ivan Dimov published more than 90 papers in refereed international scientific journals and series, has been editor of seven special volumes published by Kluwer, Springer (Lecture notes in Computer Science), World Scientific, and IOS Press. He has been involved in training young specialists: graduated students, PhD students and young post-docs. Ivan Dimov has organized nine international conferences. He is involved as a director or co-director in 12 international scientific projects (mainly EU projects). He has been an invited speaker at 35 international conferences and scientific institutions and served in program and organizing committees of many international conferences and workshops (see also http://www.reading.ac.uk/~sis04itd).