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High levels of ozone as well as particles, including Black Carbon (BC), have been observed at sites around the Mediterranean Sea, and several studies have shown very high aerosol radiative forcing in the area, but systematical, long term observations are scarce. A collaboration between the JRC and the Italian company ‘Costa Crociere’ has allowed to install a monitoring station on board the cruise liner ‘Costa Fortuna’ that performs cruises on the Mediterranean, with regular weekly tracks in the Western Mediterranean during spring, summer and autumn, and in the Eastern Mediterranean during winter. Measurements of ozone, Black Carbon (aethalometer) and particle size distributions (optical particle sizer) have been performed, starting from the autumn of 2005; this activity will continue for several years. The measured ozone concentrations are compared to those obtained by simulations in a recent model intercomparison (ACCENT-PHOTOCOM); the initial measurements are in the higher end of the range of modeled values in the winter and in the lower end during the summer. Measured concentrations of ozone and BC in 2006 are compared to model simulations for previous years and the results are discussed.

Two stage aerosol samples (PM and PM) were collected at a rural site (Erdemli) located on the coast of the Northeastern Mediterranean, between April 2001 and April 2002. A total of 581 aerosol samples were analysed for trace elements (Fe, Ti, Mn, Ca, V, Ni, Zn, Cr) and water soluble ions (Na, NH, K, Mg, Ca, Cl, Br, NO, SO, CO and MS). The annual mean PM and PM levels were 36.4 ± 27.8 μg m and 9.7 ± 5.9, respectively. The highest levels of PM10 were observed during the transition period (March, April and May) due to mineral dust transported from North Africa and during winter due to sea spray generation. However, PM levels exhibited higher concentrations during summer resulting from an enhanced production of secondary aerosols. PM, crustal elements, sea salt aerosols and NO were mainly associated with the coarse mode whereas nssSO, CO, MS, NH, Cr and Ni were found predominantly in the fine fraction. Ionic balance analysis performed in the coarse and fine aerosol fractions indicated anion and cation deficiency due to CO and H, respectively. A relationship between nssSO and NH denoted that sulphate particles were partially neutralized (70%) by ammonium. Excess-K/BC presented two distinct ratios for winter and summer, indicating two different sources: Fossil fuel burning in winter and biomass burning in summer.

During the measurement campaign performed in August/ September 2005 non-methane volatile organic compounds (NMVOCs) were studied at different locations in the city of Wroclaw, Poland. The measurements covered NMVOCs in the range of C-C. Samples were collected using Carbotrap and Carbosieve SIII solid adsorption tubes and analysed off-line by thermal desorption and GC-FID analysis. Measurements were performed on purpose to assess the contribution of different emission categories to the observed NMVOC concentrations by using chemical mass balance modelling.

Profiles of volatile organic compounds for traffic emission were measured in a downtown intersection and during driving through the city. Solvent emission profiles for industrial sources were measured in the vicinity of different factories in Wroclaw. To obtain the ambient NMVOC concentrations sampling were performed at different points located in Wroclaw. The sampling sites represented residential, industrial, mixed settings and an area down-wind from the city centre.

All measured traffic profiles were found to be very similar. The same distribution could be observed for an intersection and street driving. Obtained industrial profiles differed significantly from factory to factory. Delivered emission fingerprints were characteristic for particular solvent factories and agreed well with their emission inventory. Chapter14: Non-methane hydrocarbons (NMHCS) are important constituents of the atmosphere that contribute both to the oxidation capacity of the atmosphere and to the formation of the secondary organic aerosol. In Europe, over the last decades, many efforts have been devoted to the assignment of NMHCs sources and although NMHCS role is well established large uncertainties in their emissions still exist. Measurements of NMHCS in the atmosphere of the Eastern Mediterranean are very scarce in the literature and, therefore, the present work is willing to provide an assessment of individual NMHCS sources on both spatial and temporal basis in the Eastern Mediterranean. Intensive campaigns of several days took place each month by in situ continuous hourly measurements of NMHCS from C2 to C8 in different locations on the island of Crete, Greece (marine, rural and urban areas). All samples were analysed for 45 HMHCS with a gas chromatographic (GC) system equipped with a flame ionisation detector (FID). A simple statistical analysis of the relationship between various hydrocarbon pairs indicates influences from common sources. The average measured hydrocarbon concentrations show seasonal variations in agreement with previous published measurements. Evidence for both chemical processing and source dominating the variability of NMHCS mixing ratios were obtained. Chlorine atom concentrations were indirectly derived from changes in the patterns of the measured NMHCS. The result of the present study suggests that the Cl-atom induced reaction may be as well of considerable importance in the troposphere of the region.

Non-methane hydrocarbons (NMHC) are important constituents of the atmosphere that contribute both to the oxidation capacity of the atmosphere and to the formation of the secondary organic aerosol. In Europe, over the last decades, many efforts have been devoted to the assignment of NMHCs sources and although NMHC role is well established large uncertainties in their emissions still exist.

Measurements of NMHC in the atmosphere of the Eastern Mediterranean are very scarce in the literature and, therefore, the present work is willing to provide an assessment of individual NMHC sources on both spatial and temporal basis in the Eastern Mediterranean. Intensive campaigns of several days took place each month by in situ continuous hourly measurements of NMHC from C to C in different locations on the island of Crete, Greece (marine, rural and urban areas). All samples were analysed for 45 HMHC with a gas chromatographic (GC) system equipped with a flame ionisation detector (FID).

A simple statistical analysis of the relationship between various hydrocarbon pairs indicates influences from common sources. The average measured hydrocarbon concentrations show seasonal variations in agreement with previous published measurements. Evidence for both chemical processing and source dominating the variability of NMHC mixing ratios were obtained. Chlorine atom concentrations were indirectly derived from changes in the patterns of the measured NMHC. The result of the present study suggests that the Cl-atom induced reaction may be as well of considerable importance in the troposphere of the region.

The master chemical mechanism (MCM) is an almost explicit mechanism describing the atmospheric oxidation of 135 primary emitted volatile organic compounds (VOCs). The basis of the protocols used for constructing the MCM is described, together with the website used for dissemination. A number of applications is briefly discussed, including policy development, support for field measurements and the formation of secondary organic aerosol. Heterogeneous uptake has been incorporated into the MCM and the difficulties involved are summarized. Finally, an aqueous phase mechanism, CAPRAM is outlined.

Dust events are commonly observed every year and have been shown to strongly impact on the tropospheric ozone budget. This impact arises from the uptake of different gases, such as NO (mainly as HNO or NO), on the solid surfaces exhibited by the uplifted minerals. While such “dark” processes have been deeply studied over the last years, dust particles contain a series of oxides that may be initiate photochemical process that have not been considered so far. In fact, in addition to quartz, illite, montmorillonite, and calcite, mineral dusts are heterogeneous mixtures of mineral oxides containing small levels of TiO. In order to mimic the properties that these oxides confer to mineral Saharan dust, TiO and SiO were mixed and their heterogeneous reactions with NO studied using a horizontal wall flow tube. In addition, experiments were performed with real Arizona test dust in order to assess the importance of photochemical reactions under realistic atmospheric conditions. The effect of light (in the 380-700 nm range), temperature (in the 288-303 K range) and relative humidity have been determined. The uptake coefficient on TiO mixing in SiO increases with temperature and decreases with relative humidity. We found that despite its very low abundance, titanium dioxide (TiO) will strongly favour the photo-conversion of NO on mineral dust, nitrogen dioxide being otherwise quite unreactive on these minerals. This photoenhanced uptake of gases will in turn impact on the ozone and/or HO budget during a dust event. In addition, such photo enhanced process will affect the nitrate content of the dust particles, impacting on the optical properties of the aerosols and their associated climatic impact. We therefore exemplified, on mineral dust, that photochemical conversion on solid surfaces encountered in the troposphere needs to be considered an important process of wide impact due to the ubiquitous presence of minerals in our environment as it will change the level of photo-oxidant and aerosol optical properties.

This manuscript is a written version of the talk presented at the NATO ARW. The paper is not designed as a general overview of gas-phase processes, rather the intention has been to try and highlight work that has been going on gas-phase processes which have possible important conesquences for the complex chemistry occurring in the Mediterranean atmosphere. The manuscript is constrained to chemical processes involved in the gas-phase photooxidation of volatile organic compounds (VOCs).

Observed climatic changes at the planetary level, and these which are due to natural activities and especially human, are forced to upset the systems of global atmospheric circulation, and this is attributed to the change of the energy budget of the Earth and its Atmosphere.

The increase of the planetary temperature already observed (Figure 1), provoked by the accumulation of concentrations of gases of a high capacity of thermal energy absorption, such as the carbon dioxide (CO), methane (CH) and nitrous oxide (NO), is only one of the main results of the change at the level of the radiative contributions and losses of the planet Earth.

Oil and gas extraction and processing operations sometimes accumulate naturally occurring radioactive materials (NORM) at concentrations above normal in by-product waste streams. There are number of industries generates NORM contaminated waste in Egypt. Trench was used as a disposal facility for NORM contaminated waste at one site of the petroleum industry in Egypt.

The aim of this work is to calculate the risk and dose assessment received from trench disposal facility and salt caverns due to the climate changes after direct closure and after post closure (1000 year). RESRAD computer code with two different scenarios was used for this purpose. Results of this assessment can be helped to examine policy issues concerning different options and regulation of NORM contaminated wastes generated by petroleum industry in Egypt.

Atmospheric refractivity profile can be retrieved from Down Looking (DL) GPS radio occultation data. The main observations are the bending angle of the ray as a function of the impact parameter. Abel inversion and least squares are the possible ways to invert the profile of bending angle to the vertical profile of refractivity.

The current paper uses simulated GPS data to compare the merits and limitations of the least squares and Abel techniques. The simulation uses model refractivity from MSIS dry Model, wet model and radiosonde data. The result shows that it is possible to produce accurate vertical refractivity profile using either least squares or Abel inversion. Abel inversion is slightly more accurate than least squares. The percentage of the relative error of the two methods is in the range of 0.2-0.25. Least squares technique is more sensitive to biases than Abel inversion. Abel inversion solution requires much less computation time compared to least squares one.