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В статье рассматривается одна из находок «владычной канцелярии» XIV в., обнаруженной на Верхнем городище г. Торжка Тверской области в 2005 г. Булава-пернат представляет собой редкий тип вооружения, выполненного из железа и инкрустированного орнаментом из растительных мотивов и букв квадратного монгольского письма. Подобная находка в представительстве Новгородской архиепископии в Торжке может говорить о статусности подобного рода вооружения., The paper explores one of the finds in the ’Office of archbishop representatives’ of the 14th century discovered in the Upper Hillfort of Torzhok in the Tver Region in 2005. The mace-head (pernach) is a rare type of weapon made of iron inlaid with floral motif and letters of the Mongolian square script. This kind of find in the representative office of the Novgorod archdiocese in Torzhok suggests a high status of this type of weapon., №253 (2019)

Long-term monitoring of data of ambient mercury (Hg) on a global scale to assess its emission, transport, atmospheric chemistry, and deposition processes is vital to understanding the impact of Hg pollution on the environment. The Global Mercury Observation System (GMOS) project was funded by the European Commission (http://www.gmos.eu) and started in November 2010 with the overall goal to develop a coordinated global observing system to monitor Hg on a global scale, including a large network of ground-based monitoring stations, ad hoc periodic oceanographic cruises and measurement flights in the lower and upper troposphere as well as in the lower stratosphere. To date, more than 40 ground-based monitoring sites constitute the global network covering many regions where little to no observational data were available before GMOS. This work presents atmospheric Hg concentrations recorded worldwide in the framework of the GMOS project (2010-2015), analyzing Hg measurement results in terms of temporal trends, seasonality and comparability within the network. Major findings highlighted in this paper include a clear gradient of Hg concentrations between the Northern and Southern hemispheres, confirming that the gradient observed is mostly driven by local and regional sources, which can be anthropogenic, natural or a combination of both. Fil: Sprovieri, Francesca. Institute of Atmospheric Pollution Research; Italia Fil: Pirrone, Nicola. Institute of Atmospheric Pollution Research; Italia Fil: Bencardino, Mariantonia. Institute of Atmospheric Pollution Research; Italia Fil: D'Amore, Francesco. Institute of Atmospheric Pollution Research; Italia Fil: Carbone, Francesco. Institute of Atmospheric Pollution Research; Italia Fil: Cinnirella, Sergio. Institute of Atmospheric Pollution Research; Italia Fil: Mannarino, Valentino. Institute of Atmospheric Pollution Research; Italia Fil: Landis, Matthew. US Environmental Protection Agency; Estados Unidos Fil: Ebinghaus, Ralf. Helmholtz Zentrum; Alemania Fil: Weigelt, Andreas. Helmholtz Zentrum; Alemania Fil: Brunke, Ernst Günther. South African Weather Service; Sudáfrica Fil: Labuschagne, Casper. South African Weather Service; Sudáfrica Fil: Martin, Lynwill. South African Weather Service; Sudáfrica Fil: Munthe, John. Swedish Environmental Research Inst. Ltd.; Suecia Fil: Wängberg, Ingvar. Swedish Environmental Research Inst. Ltd.; Suecia Fil: Artaxo, Paulo. Universidade de Sao Paulo; Brasil Fil: Morais, Fernando. Universidade de Sao Paulo; Brasil Fil: De Melo Jorge Barbosa, Henrique. Universidade de Sao Paulo; Brasil Fil: Brito, Joel. Universidade de Sao Paulo; Brasil Fil: Cairns, Warren. Universita' Ca' Foscari Di Venezia; Italia Fil: Barbante, Carlo. Universita' Ca' Foscari Di Venezia; Italia. Institute for the Dynamics of Environmental Processes; Italia Fil: Dieguez, Maria del Carmen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina Fil: Garcia, Patricia Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina Fil: Aurélien, Dommergue. Centre National de la Recherche Scientifique; Francia. University Grenoble Alpes; Francia Fil: Angot, Helene. Centre National de la Recherche Scientifique; Francia. University Grenoble Alpes; Francia Fil: Magand, Olivier. Centre National de la Recherche Scientifique; Francia. University Grenoble Alpes; Francia Fil: Skov, Henrik. University Aarhus; Dinamarca Fil: Horvat, Milena. Jožef Stefan Institute; Eslovenia Fil: Kotnik, Jože. Jožef Stefan Institute; Eslovenia Fil: Alana Read, Katie. University of York; Reino Unido Fil: Mendes Neves, Luis. Cape Verde Observatory; Brasil Fil: Manfred Gawlik, Bernd. Joint Research Centre; Italia Fil: Sena, Fabrizio. Joint Research Centre; Italia Fil: Mashyanov, Nikolay. St. Petersburg State University; Rusia Fil: Obolkin, Vladimir. Limnological Institute SB RAS; Rusia Fil: Wip, Dennis. University of Suriname; Surinam Fil: Bin Feng, Xin. Institute Of Geochemistry Chinese Academy Of Sciences; China Fil: Zhang, Hui. Institute Of Geochemistry Chinese Academy Of Sciences; China Fil: Fu, Xuewu. Institute Of Geochemistry Chinese Academy Of Sciences; China Fil: Ramachandran, Ramesh. Anna University; India Fil: Cossa, Daniel. Centre Méditerranée; Francia Fil: Knoery, Joël. Centre Atlantique; Francia Fil: Marusczak, Nicolas. Centre Méditerranée; Francia Fil: Nerentorp, Michelle. Chalmers University Of Technology; Suecia Fil: Norstrom, Claus. University Aarhus; Dinamarca

Mercury measurements at a coastal site in Nieuw Nickerie (5°56' N, 56°59' W), Suriname, provide the only continuous records of atmospheric mercury in the tropics. Here we evaluate observations of total gaseous mercury (TGM) during 2007. Nieuw Nickerie typically samples marine air from the Atlantic Ocean, with occasional influence from continental South America. Over the year, average concentrations are 1.40 ng m−3. As the intertropical convergence zone passes over Suriname twice each year, the site samples both northern and southern hemispheric air masses. We use back trajectories to classify each measurement by hemisphere, as well as continental or ocean. For air passing over ocean before sampling, TGM concentrations are 10% higher in air coming from the Northern Hemisphere (1.45 ng m−3) than from the Southern Hemisphere (1.32 ng m−3). Air from the South American continent also carries higher TGM (1.43 ng m−3) than air from the South Atlantic Ocean, with most of these trajectories occurring in August and September. Biomass burning in Brazil peaks in the same months and likely contributes significantly to elevated concentrations seen in Nickerie. We also compare the observed seasonal cycle to two atmospheric mercury chemistry and transport models (GRAHM and GEOS-Chem). Both models simulate transition between northern and southern hemispheric air, thus capturing the seasonal cycle; however the models overestimate the TGM concentrations during months when Nickerie samples Northern Hemisphere air. It is difficult to determine whether the models' sources or sinks in the Northern Hemisphere tropics are responsible.

Hourly data (1994-2009) of surface ozone concentrations at eight monitoring sites have been investigated to assess target level and long-term objective exceedances and their trends. The European Union (EU) ozone target value for human health (60 ppb-maximum daily 8-hour running mean) has been exceeded for a number of years for almost all sites but never exceeded the set limit of 25 exceedances in one year. Second highest annual hourly and 4th highest annual 8-hourly mean ozone concentrations have shown a statistically significant negative trend for in-land sites of Cork-Glashaboy, Monaghan and Lough Navar and no significant trend for the Mace Head site. Peak afternoon ozone concentrations averaged over a three year period from 2007 to 2009 have been found to be lower than corresponding values over a three-year period from 1996 to 1998 for two sites: Cork-Glashaboy and Lough Navar sites. The EU long-term objective value of AOT40 (Accumulated Ozone Exposure over a threshold of 40 ppb) for protection of vegetation (3 ppm-hour, calculated from May to July) has been exceeded, on an individual year basis, for two sites: Mace Head and Valentia. The critical level for the protection of forest (10 ppm-hour from April to September) has not been exceeded for any site except at Valentia in the year 2003. AOT40-Vegetation shows a significant negative trend for a 3-year running average at Cork-Glashaboy (-0.13 +/- 0.02 ppm-hour per year), at Lough Navar (-0.05 +/- 0.02 ppm-hour per year) and at Monaghan (-0.03 +/- 0.03 ppm-hour per year-not statistically significant) sites. No statistically significant trend was observed for the coastal site of Mace head. Overall, with the exception of the Mace Head and Monaghan sites, ozone measurement records at Irish sites show a downward negative trend in peak values that affect human health and vegetation. (c) Author(s) 2012. This work is distributed under the Creative Commons Attribution 3.0 License.

International audience; Twenty-one cases of boundary-layer structure were retrieved by three co-located remote sensors, One LIDAR and two ceilometers at the coastal site of Mace Head, Ireland. Data were collected during the ICOS field campaign held at the GAW Atmospheric Station of Mace Head, Ireland, from 8th to 28th of June, 2009. The study is a two-step investigation of the BL structure based on (i) the intercomparison of the backscatter profiles from the three laser sensors, namely the Leosphere ALS300 LIDAR, the Vaisala CL31 ceilometer and the Jenoptik CHM15K ceilometer; (ii) and the comparison of the backscatter profiles with twenty-three radiosoundings performed during the period from the 8th to the 15th of June, 2009. The sensor-independent Temporal Height-Tracking algorithm was applied to the backscatter profiles as retrieved by each instrument to determine the decoupled structure of the BL over Mace Head. The LIDAR and ceilometers-retrieved BL heights were compared to the radiosoundings temperature profiles. The comparison between the remote and the in-situ data proved the existence of the inherent link between temperature and aerosol backscatter profiles and opened at future studies focusing on the further assessment of LIDAR-ceilometer comparison. © 2012 Conor Milroy et al.

Halocarbons are powerful greenhouse gases capable of significantly influencing the radiative forcing of the Earth’s atmosphere. Halocarbons are monitored in several stations which are globally distributed in order to assess long term atmospheric trends and to identify source regions. However, to achieve these aims the definition of background mixing ratios, i.e. the mixing ratio in a given air mass when the recent contribution of local sources is absent, is necessary. This task can be accomplished using different methods. This paper presents a statistical methodology that has been devised specifically for a mountain site located in Continental Europe (Monte Cimone, Italy), characterised by the vicinity of strong sources. The method involves the decomposition of the observed data distribution into a Gaussian distribution, representative of background values, and a Gamma distribution, ascribable to contribution from stronger sources. The method has been applied to a time series from a European marine remote station (Mace Head, Ireland) as well as to time series from Monte Cimone. A comparison of the methodology described in this paper with a well-established meteorological filtering procedure at Mace Head has shown an excellent agreement. A comparison of the baselines at Mace Head, Mt. Cimone and the Swiss alpine station of the Jungfraujoch highlighted the occurrence of a specific background concentration. Although this paper presents the application of the method to three hydrofluorocarbons, the proposed methodology can be extended to any long lived atmospheric component for which a long term time series is available and at any location even if affected by strong source regions.

Seawater concentrations of the four brominated trace gases dibromomethane (CH2Br2), bromodichloromethane (CHBrCl2), dibromochloromethane (CHBr2Cl) and bromoform (CHBr3) were measured at different depths of the water column in the Iberian upwelling off Portugal during summer 2007. Bromocarbon concentrations showed elevated values in recently upwelled and aged upwelled waters (mean values of 30 pmol L−1 for CHBr3), while values in the open ocean were significantly lower (7.4 pmol L−1 for CHBr3). Correlations with biological variables and marker pigments indicated that phytoplankton could be identified as a weak bromocarbon source in the open ocean. In upwelled water masses along the coast, halocarbons were not correlated to Chl-a, indicating an external source, overlapping the possible internal production by phytoplankton. We showed that the tidal frequency had a significant influence on halocarbon concentrations in the upwelling and we linked those findings to a strong intertidal coastal source, as well as to a transport of those halocarbon enriched coastal waters by westward surface upwelling currents. Coastal sources and transport can be accounted for maximum values of up to 185.1 pmol L−1 CHBr3 in the upwelling. Comparison with other productive marine areas revealed that the Iberian upwelling had stronger halocarbon sources than the phytoplankton dominated sources in the Mauritanian upwelling. However, the concentrations off the Iberian Peninsula were still much lower than those of coastal macroalgal influenced waters or those of polar regions dominated by cold water adapted diatoms.

The European integrated project on Aerosol Cloud Climate and Air Quality Interactions (EUCAARI) focuses on understanding the interactions of climate and air pollution. As part of the EUCAARI intensive observational period, an aircraft field campaign (EUCAARI-LONGREX) was conducted in May 2008. The campaign aimed at studying the distribution and evolution of air mass properties on a continental scale. Airborne aerosol and trace gas measurements were performed aboard the German DLR Falcon 20 and the British FAAM BAe-146 aircraft. This paper outlines the meteorological situation over Europe during May 2008 and the temporal and spatial evolution of predominantly anthropogenic particulate pollution inside the boundary layer and the free troposphere. Time series data of six selected ground stations are used to discuss continuous measurements besides the single flights. The observations encompass total and accumulation mode particle number concentration (0.1–0.8 μm) and black carbon mass concentration as well as several meteorological parameters. Vertical profiles of total aerosol number concentration up to 10 km are compared to vertical profiles probed during previous studies. During the first half of May 2008 an anticyclonic blocking event dominated the weather over Central Europe. It led to increased pollutant concentrations within the centre of the high pressure inside the boundary layer. Due to long-range transport the accumulated pollution was partly advected towards Western and Northern Europe. The measured aerosol number concentrations over Central Europe showed in the boundary layer high values up to 14 000 cm−3 for particles in diameter larger 10 nm and 2300 cm−3 for accumulation mode particles during the high pressure period, whereas the middle free troposphere showed rather low concentrations of particulates. Thus a strong negative gradient of aerosol concentrations between the well mixed boundary layer and the clean middle troposphere occurred.

Data from various stations having different measurement record periods between 1988 and 2007 are analyzed to investigate the surface ozone concentration, long-term trends, and seasonal changes in and around Ireland. Time series statistical analysis is performed on the monthly mean data using seasonal and trend decomposition procedures and the Box-Jenkins approach (autoregressive integrated moving average). In general, ozone concentrations in the Irish region are found to have a negative trend at all sites except at the coastal sites of Mace Head and Valentia. Data from the most polluted Dublin city site have shown a very strong negative trend of -0.33 ppb/yr with a 95% confidence limit of 0.17 ppb/yr (i.e., -0.33 +/- 0.17) for the period 2002-2007, and for the site near the city of Cork, the trend is found to be -0.20 +/- 0.11 ppb/yr over the same period. The negative trend for other sites is more pronounced when the data span is considered from around the year 2000 to 2007. Rural sites of Wexford and Monaghan have also shown a very strong negative trend of -0.99 +/- 0.13 and -0.58 +/- 0.12, respectively, for the period 2000-2007. Mace Head, a site that is representative of ozone changes in the air advected from the Atlantic to Europe in the marine planetary boundary layer, has shown a positive trend of about +0.16 +/- 0.04 ppb per annum over the entire period 1988-2007, but this positive trend has reduced during recent years (e. g., in the period 2001-2007). Cluster analysis for back trajectories are performed for the stations having a long record of data, Mace Head and Lough Navar. For Mace Head, the northern and western clean air sectors have shown a similar positive trend (+0.17 +/- 0.02 ppb/yr for the northern sector and +0.18 +/- 0.02 ppb/yr for the western sector) for the whole period, but partial analysis for the clean western sector at Mace Head shows different trends during different time periods with a decrease in the positive trend since 1988 indicating a deceleration in the ozone trend for Atlantic air masses entering Europe.

Understanding the surface O-3 response over a "receptor" region to emission changes over a foreign "source" region is key to evaluating the potential gains from an international approach to abate ozone (O-3) pollution. We apply an ensemble of 21 global and hemispheric chemical transport models to estimate the spatial average surface O-3 response over east Asia (EA), Europe (EU), North America (NA), and south Asia (SA) to 20% decreases in anthropogenic emissions of the O-3 precursors, NOx, NMVOC, and CO (individually and combined), from each of these regions. We find that the ensemble mean surface O-3 concentrations in the base case (year 2001) simulation matches available observations throughout the year over EU but overestimates them by > 10 ppb during summer and early fall over the eastern United States and Japan. The sum of the O-3 responses to NOx, CO, and NMVOC decreases separately is approximately equal to that from a simultaneous reduction of all precursors. We define a continental-scale "import sensitivity" as the ratio of the O-3 response to the 20% reductions in foreign versus "domestic" (i.e., over the source region itself) emissions. For example, the combined reduction of emissions from the three foreign regions produces an ensemble spatial mean decrease of 0.6 ppb over EU (0.4 ppb from NA), less than the 0.8 ppb from the reduction of EU emissions, leading to an import sensitivity ratio of 0.7. The ensemble mean surface O-3 response to foreign emissions is largest in spring and late fall (0.7-0.9 ppb decrease in all regions from the combined precursor reductions in the three foreign regions), with import sensitivities ranging from 0.5 to 1.1 (responses to domestic emission reductions are 0.8-1.6 ppb). High O-3 values are much more sensitive to domestic emissions than to foreign emissions, as indicated by lower import sensitivities of 0.2 to 0.3 during July in EA, EU, and NA when O-3 levels are typically highest and by the weaker relative response of annual incidences of daily maximum 8-h average O-3 above 60 ppb to emission reductions in a foreign region(< 10-20% of that to domestic) as compared to the annual mean response (up to 50% of that to domestic). Applying the ensemble annual mean results to changes in anthropogenic emissions from 1996 to 2002, we estimate a Northern Hemispheric increase in background surface O-3 of about 0.1 ppb a(-1), at the low end of the 0.1-0.5 ppb a(-1) derived from observations. From an additional simulation in which global atmospheric methane was reduced, we infer that 20% reductions in anthropogenic methane emissions from a foreign source region would yield an O-3 response in a receptor region that roughly equals that produced by combined 20% reductions of anthropogenic NOx, NMVOC, and CO emissions from the foreign source

An aerosol time-of-flight mass spectrometer was deployed at Mace Head (Ireland) during August 2002. The measurements provide qualitative chemical composition and size distribution ( 0.3-3 um) information for single particles. Three broad categories of particles: sea salt, dust, and carbon-containing particles were identified and apportioned, and their temporal evolution ( 1 hour resolution) is described. Aerosol sources were correlated with meteorological factors and with air mass trajectories, demonstrating long-range transport of different continental air masses from Europe, Africa, and America. The major class of particles was derived from sea salt and was subdivided into pure, mixed, and aged sea salt according to the extent of displacement of chloride by nitrate. Two types of dust particles were found mainly in the coarse mode (>1 um); the former, thought to originate from the Sahara, presented an aluminium/silicon signature, while the latter, of more local origin, had a calcium-rich composition. Carbon-containing particles were mainly distributed in the fine mode (

Total aerosol mass loading, aerosol absorption, and black carbon ( BC) content were determined from aerosol collected on 598 quartz fiber filters at a remote, semiarid site near Orogrande, New Mexico from December 1989 to October 1995. Aerosol mass was determined by weighing filters before and after exposure, and aerosol absorption was determined by measuring the visible light transmitted through loaded filter samples and converting these measurements to aerosol absorption. BC content was determined by measuring visible light transmitted through filter samples before and after firing and converting the absorption to BC mass, assuming a BC absorption cross section of 19 m(2)/g in the fiber filter medium. Two analyses were then performed on each of the logged variables: an autoregressive integrating moving average (ARIMA) analysis and a decomposition analysis using an autoregressive model to accommodate first-order autocorrelation. The two analyses reveal that BC mass has no statistically significant seasonal dependence at the 5% level of significance but only random fluctuations varying around an average annual value that has a long-term decreasing trend (from 0.16 to 0.11 mug/m(3) during 1990-1995). Aerosol absorption, which is dominated by BC, also displays random fluctuations about an average value, and decreases from 1.9 Mm(-1) to 1.3 Mm(-1) during the same period. Unlike BC, aerosol mass at the Orogrande site displays distinctly different character. The analyses reveal a pronounced seasonal dependence, but no long-term trend for aerosol mass. The seasonal indices resulting from the autoregression analysis have a minimum in January (-0.78) and maximum in June (+0.58). The geometric mean value over the 1990-1995 period for aerosol mass is 16.0 mug/m(3). Since BC aerosol at the Orogrande site is a product of long-range atmospheric transport, a back trajectory analysis of air masses was conducted. Back trajectory analyses indicate that air masses traversing high population centres on the west coast of the USA can lead to significant BC loading, while air masses originating from the southeast of the site tend to have less BC. Additional aerosol measurements are reported for a remote maritime site located on the Atlantic side of the former Panama Canal Zone for the 1976-1979 period, although these data have been analyzed with less statistical rigor. The average geometric mean value of aerosol mass loading for this site is 9.7 mug/m(3), with a significant decreasing trend of -19% per year. The mean value of aerosol absorption is 0.59 Mm(-1), with a decreasing trend of -15% per year.

Observations of a chemical at a point in the atmosphere typically show sudden transitions between episodes of high and low concentration. Often these are associated with a rapid change in the origin of air arriving at the site. Lagrangian chemical models riding along trajectories can reproduce such transitions, but small timing errors from trajectory phase errors dramatically reduce the correlation between modeled concentrations and observations. Here the origin averaging technique is introduced to obtain maps of average concentration as a function of air mass origin for the East Atlantic Summer Experiment 1996 (EASE96, a ground-based chemistry campaign). These maps are used to construct origin averaged time series which enable comparison between a chemistry model and observations with phase errors factored out. The amount of the observed signal explained by trajectory changes can be quantified, as can the systematic model errors as a function of air mass origin. The Cambridge Tropospheric Trajectory model of Chemistry and Transport (CiTTyCAT) can account for over 70% of the observed ozone signal variance during EASE96 when phase errors are side-stepped by origin averaging. The dramatic increase in correlation (from 23% without averaging) cannot be achieved by time averaging. The success of the model is attributed to the strong relationship between changes in ozone along trajectories and their origin and its ability to simulate those changes. The model performs less well for longer-lived chemical constituents because the initial conditions 5 days before arrival are insufficiently well known.

We investigate the temporal trends of peak ozone in Switzerland for the 1990-2014 time period. The meteorological conditions have a large influence on ozone formation and drive a large part of the variability in ozone observations. Therefore, the influence of meteorology on ozone was estimated using generalized additive models and removed from the ozone observations. A variable selection method was used for model building allowing the detection of the meteorological variables that have the largest effect on the variability of daily maximum ozone at each considered station. It was found that peak concentrations of ozone have been reducing in most of the stations, indicating a positive effect of implemented air pollution control measures on locally produced ozone. In the remote, high alpine site of Jungfraujoch a small upward trend of peak ozone was observed, most likely due to influence of hemispheric background ozone. In the most polluted traffic sites, peak ozone has for a different reason also been increasing until around 2003, when this trend started to level off. In traffic sites the increasing ozone concentrations due to reduced titration by nitrogen monoxide was the dominating process. One of the advantages of meteorological correction of ozone observations for trend estimation is that the uncertainty in the calculated trends is reduced. In addition, trend estimation based on meteorologically corrected ozone is less influenced by exceptional meteorological events during a specific time period, such as heat waves or by temporal changes in meteorological variables.

Air quality measures that were implemented in Europe in the 1990s resulted in reductions of ozone precursor concentrations. In this study, the effect of these reductions on ozone is investigated by analyzing surface measurements of this pollutant for the time period between 2000 and 2015. Using a nonparametric timescale decomposition methodology, the long-term, seasonal and short-term variation in ozone observations were extracted. A clustering algorithm was applied to the different timescale variations, leading to a classification of sites across Europe based on the temporal characteristics of ozone. The clustering based on the long-term variation resulted in a site-type classification, while a regional classification was obtained based on the seasonal and short-term variations. Long-term trends of deseasonalized mean and meteo-adjusted peak ozone concentrations were calculated across large parts of Europe for the time period 2000–2015. A multidimensional scheme was used for a detailed trend analysis, based on the identified clusters, which reflect precursor emissions and meteorological influence either on the inter-annual or the short-term timescale. Decreasing mean ozone concentrations at rural sites and increasing or stabilizing at urban sites were observed. At the same time, downward trends for peak ozone concentrations were detected for all site types. In addition, a reduction of the amplitude in the seasonal cycle of ozone and a shift in the occurrence of the seasonal maximum towards earlier time of the year were observed. Finally, a reduced sensitivity of ozone to temperature was identified. It was concluded that long-term trends of mean and peak ozone concentrations are mostly controlled by precursor emissions changes, while seasonal cycle trends and changes in the sensitivity of ozone to temperature are among other factors driven by regional climatic conditions.