409 Journal of Environmental Protection and Ecology 13, No 2, 409–419 (2012) Air pollution * For correspondence. NECESSITY OF COMPLEMENTARY VERTICALLY-RESOLVED LIDAR OBSERVATION FOR GROUND AIR POLLUTION ANALYSIS IN WESTERN ROMANIA I. VETRES а , I. IONEL а , M.-M. CAZACU b *, I. BALIN c a Faculty of Mechanical Engineering, ‘Politehnica’ University of Timisoara, 1 Mihai Vitas Blvd., 300 222 Timisoara, Romania E-mail: vetres.i@gmail.com; ioana.ionel@mec.upt.ro b Faculty of Physics, ‘Al. I. Cuza’ University, Iasi, Romania E-mail: cazacumarius@gmail.com c EnviroScopY, PSE(A)- EPFL, 1015 Lausanne, Switzerland E-mail: ioan.balin@enviroscopy.com Abstract. The western part of Romania, i.e. Banat, is one of the most developed industrial areas of Romania, with many urban agglomerations (Timisoara, Arad, Lugoj, Jimbolia). Thus, the regional air pollution monitoring and assessment are of paramount importance for the sustainable development of the society in the region. This work is focused on the identification of the air pollution regimes and specificity, as well as on the main driven factors. Representative ground measurements data sets of O 3 , NO x , SO 2 and PM10, will be analysed and presented in the context of regional photo- chemistry potential. The effect of the traffic through an urban region will be also analysed. Finally, the complementarily necessity of the LIDAR-based observations for the evaluation of the vertical mixing structures, planetary boundary layer dynamics, and generated specific regional effects in the region will be demonstrated. Keywords: NO x , LIDAR, regional air pollution, aerosols, planetary boundary layer. AIMS AND BACKGROUND The main purpose of this research is to identify the air pollution regimes and their specificity in the Timisoara city (urban episodes) and the majors sources of the pollution. In situ measurements were accomplished in different relevant locations in Timisoara, with or without traffic, in order to identify the traffic influences on air quality. Point monitor measurement equipments were used for monitoring the pollution level at ground surface and allowing the identification of pollution sources. Our conclusion is that in spite of the usefulness of these measured values and the information generated by the processing of the data there is not sufficient relevant information for identifying at a regional scale the dynamics of the atmosphere over the urban area and more particular the aerosols height distribution and their