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Chemical composition variations of aerosols during summer and winter seasons have been investigated using an Aerosol Mass Spectrometer (AMS) at Magurele, a city near Bucharest, Romania. Proportions of chemical species, concentration time series, mass range distribution and aerodynamic size distribution of aerosols have been analyzed. AMS measurements proved that the organics, nitrate, sulphate and ammonium, with small amounts of chloride were the main species at ground level during the investigated period. Important differences have been noticed between hot and cold seasons related to the total submicronic aerosol concentration and composition. The submicronic aerosols loadings are almost two times higher in summer in comparison with wintertime. Proportions of the species are evenly distributed during wintertime. One accumulation peak can be depicted with diameter between 450 to 600 nm. The fine particle mode consisted typically of organics, sulphate and ammonium during summertime, with size distribution centered at about 400-500 nm. [ABSTRACT FROM AUTHOR]

This study analyses the relationship between the scattering properties and the chemical compounds internal mixture of the aerosols near Bucharest, Romania. Several cases of local aerosols influenced by heating sources, like wood or fossil fuel, are characterized in order to retrieve the winter period specificity. Correlation between organic and inorganic aerosols composition from mass spectrometry measurements made with Compact Time (CT) of Flight Aerosol Mass Spectrometer (AMS) and scattering coefficient derived from Nephelometer measurements is highlighted. The scattering coefficient tendency can be assigned to some of the chemical components of the aerosols, exploiting the correlation coefficient with some fragments during the measurements period. High concentrations of organic markers specific for CO2 fragment (m/z 44) indicate the presence of oxygenated organic aerosols with low volatility. The aerosols aging process is emphasized by ratio between markers with different degrees of oxidation, as f44 and f43 (high oxidized marker, m/z 44 to total signal and low oxidized marker m/z 43 to total signal). Lower values are characteristic for the beginning of February and higher at the end of February and beginning of March. During winter, several aerosol sources were present, the m/z 57 marker being related to traffic. Strong correlations were revealed between m/z 43, 60 and 73 and the scattering coefficient. [ABSTRACT FROM AUTHOR]

In this paper we present results from the first European (EUR) and North Atlantic (NAT) volcanic ash exercise (VOLCEX) which includes all the warning phases associated as alerting, reactive and proactive phases. Because volcanic ash represents one of the most serious natural hazards that could affect aviation safety, the measurement campaign was focused on improving the reaction of relevant authorities in case of airspace contamination with volcanic ash and, particularly, to assess the current operational procedures and information flows. Organized in the frame of the International Civil Aviation Organization - EUR/NAT Office in Paris, the VOLCEX measurements in Romania were coordinated by the Romanian Atmospheric 3D research Observatory (RADO) and Romanian Air Traffic Services (ROMATSA). The results from lidar measurements from Bucharest, Iasi, Cluj-Napoca-Napoca and Timisoara are presented, emphasizing the dynamics of the aerosol layers and the estimation of particle mass concentrations in the free troposphere. [ABSTRACT FROM AUTHOR]

This study focuses on the local scale behavior of SO2 emissions resulting from lignite-combustion thermal power plants. The investigations aimed at monitoring the SO2 emissions and imissions over a two week period in September 2010. One of the largest power plants from Eastern Europe was chosen for monitoring using different optoelectronic techniques. Rovinari power plant (44°54'45"N - 23°09'44"E) is one of the largest electricity suppliers of Romania, having 4 groups of 330 MW each, with a total installed capacity of 1420 MW and is located in the Rovinari-Motru coal mining area This power plant along with similar facilities located in south-west of Romania is responsible for local and regional pollution problems concerning acid rain, formation of fine particulate matter, smog etc. Emissions from the stacks of Rovinari power plant were monitored with a UV camera that uses the strong absorption of SO2 molecules between 280-320 nm. Images with UV camera were collected from distances ranging between 1 and 2 km. Immisions measurements were made simultaneously with a HORIBA SO2 analyzer for continuous monitoring of atmospheric SO2 imissions using UV fluorescence method. Within the two weeks of measurements the SO2 immisions hourly limit of 350 µg/m³ was exceeded two times, the highest measured concentration of 590 µg/m³ occurring during stable meteorological conditions (very low wind speeds) inhibiting dispersion and favoring the accumulation of SO2 on a local scale. At the stacks, SO2 concentrations were constantly over 1000 ppm*m during the analyzed days. [ABSTRACT FROM AUTHOR]

The chemical composition, complete mass spectra and size distribution of ambient aerosols was analyzed for several weeks during spring 2010 near Bucharest, Romania. Preliminary results of the first measurements using an Aerosol Mass Spectrometer (AMS) are presented in this study. A significant accumulation mode with a peak around 350-600 nm was usually observed principally composed of sulfate, organics, ammonium and some nitrate. Particle-size distribution measurements over the full range of the fine fraction of the atmospheric aerosol have been done using two instruments based on time of flight and in a side-by-side configuration, an AMS and an aerosol particle sizer (APS). The particle size distributions characterizing different chemical components showed similar peaks and shapes suggesting that nitrate, sulfate, and organic species are probably internally mixed in the same particles. [ABSTRACT FROM AUTHOR]