The Finokalia Aerosol Measurement Experiment – 2008 (FAME-08): an overview

A month (4 May to 8 June 2008) of ambient aerosol, air ion and gas phase sampling (Finokalia Aerosol Measurement Experiment 2008, FAME-08) was conducted at Finokalia, on the island of Crete, Greece. The purpose of the study was to characterize the physical and chemical properties of aged aerosol and to investigate new particle formation. Measurements included aerosol and air ion size distributions, size-resolved chemical composition, organic aerosol thermal volatility, water uptake and particle optical properties (light scattering and absorption). Statistical analysis of the aerosol mass concentration variations revealed the absence of diurnal patterns suggesting the lack of strong local sources. Sulfates accounted for approximately half of the particulate matter less than 1 micrometer in diameter (PM<sub>1</sub>) and organics for 28%. The PM<sub>1</sub> organic aerosol fraction was highly oxidized with 80% water soluble. The supermicrometer particles were dominated by crustal components (50%), sea salt (24%) and nitrates (16%). The organic carbon to elemental carbon (OC/EC) ratio correlated with ozone measurements but with a one-day lag. The average OC/EC ratio for the study period was equal to 5.4. For three days air masses from North Africa resulted in a 6-fold increase of particulate matter less than 10 micrometers in diameter (PM<sub>10</sub>) and a decrease of the OC/EC ratio by a factor of 2. Back trajectory analysis, based on FLEXPART footprint plots, identified five source regions (Athens, Greece, Africa, other continental and marine), each of which influenced the PM<sub>1</sub> aerosol composition and properties. Marine air masses had the lowest PM<sub>1</sub> concentrations and air masses from the Balkans, Turkey and Eastern Europe the highest

Multi-year chemical composition of the fine-aerosol fraction in Athens, Greece, with emphasis on the contribution of residential heating in wintertime

In an attempt to take effective action towards mitigating pollution episodes in Athens, precise knowledge of PM2.5 composition and its sources is a prerequisite. Thus, a 2-year chemical composition dataset from aerosol samples collected in an urban background site in central Athens from December 2013 to March 2016 has been obtained and a positive matrix factorization (PMF) was applied in order to identify and apportion fine aerosols to their sources. A total of 850 aerosol samples were collected on a 12 to 24&thinsp;h basis and analyzed for major ions, trace elements, and organic and elemental carbon, allowing us to further assess the impact of residential heating as a source of air pollution over Athens.The ionic and carbonaceous components were found to constitute the major fraction of the PM2.5 aerosol mass. The annual contribution of the ion mass (IM), particulate organic mass (POM), dust, elemental carbon (EC), and sea salt (SS) was calculated at 31&thinsp;%, 38&thinsp;%, 18&thinsp;%, 8&thinsp;%, and 3&thinsp;%, respectively, and exhibited considerable seasonal variation. In winter, the share of IM was estimated down to 23&thinsp;%, with POM&thinsp;+ EC being the dominant component accounting for 52&thinsp;% of the PM2.5 mass, while in summer, IM (42&thinsp;%) and carbonaceous aerosols (41&thinsp;%) contributed almost equally.Results from samples collected on a 12&thinsp;h basis (day and night) during the three intensive winter campaigns indicated the impact of heating on the levels of a series of compounds. Indeed, PM2.5, EC, POM, NO3−, C2O42−, non sea salt (nss) K+ and selected trace metals including Cd and Pb were increased by up to a factor of 4 in the night compared to the day, highlighting the importance of heating on air quality in Athens. Furthermore, in order to better characterize wintertime aerosol sources and quantify the impact of biomass burning on PM2.5 levels, source apportionment was performed. The data can be interpreted on the basis of six sources, namely biomass burning (31&thinsp;%), vehicular emissions (19&thinsp;%), heavy oil combustion (7&thinsp;%), regional secondary (21&thinsp;%), marine aerosols (9&thinsp;%), and dust particles (8&thinsp;%). Regarding night-to-day patterns their contributions shifted from 19&thinsp;%, 19&thinsp;%, 8&thinsp;%, 31&thinsp;%, 12&thinsp;%, and 10&thinsp;% of the PM2.5 mass during day to 39&thinsp;%, 19&thinsp;%, 6&thinsp;%, 14&thinsp;%, 7&thinsp;%, and 7&thinsp;% during the night, underlining the significance of biomass burning as the main contributor to fine particle levels during nighttime in winter.</p

Sources and processes that control the submicron organic aerosol composition in an urban Mediterranean environment (Athens): a high temporal-resolution chemical composition measurement study

Submicron aerosol chemical composition was studied during a year-long period (26 July 2016–31 July 2017) and two wintertime intensive campaigns (18 December 2013–21 February 2014 and 23 December 2015–17 February 2016), at a central site in Athens, Greece, using an Aerosol Chemical Speciation Monitor (ACSM). Concurrent measurements included a particle-into-liquid sampler (PILS-IC), a scanning mobility particle sizer (SMPS), an AE-33 Aethalometer, and ion chromatography analysis on 24 or 12&thinsp;h filter samples. The aim of the study was to characterize the seasonal variability of the main submicron aerosol constituents and decipher the sources of organic aerosol (OA). Organics were found to contribute almost half of the submicron mass, with 30&thinsp;min resolution concentrations during wintertime reaching up to 200&thinsp;µg&thinsp;m−3. During winter (all three campaigns combined), primary sources contributed about 33&thinsp;% of the organic fraction, and comprised biomass burning (10&thinsp;%), fossil fuel combustion (13&thinsp;%), and cooking (10&thinsp;%), while the remaining 67&thinsp;% was attributed to secondary aerosol. The semi-volatile component of the oxidized organic aerosol (SV-OOA; 22&thinsp;%) was found to be clearly linked to combustion sources, in particular biomass burning; part of the very oxidized, low-volatility component (LV-OOA; 44&thinsp;%) could also be attributed to the oxidation of emissions from these primary combustion sources. These results, based on the combined contribution of biomass burning organic aerosol (BBOA) and SV-OOA, indicate the importance of increased biomass burning in the urban environment of Athens as a result of the economic recession. During summer, when concentrations of fine aerosols are considerably lower, more than 80&thinsp;% of the organic fraction is attributed to secondary aerosol (SV-OOA 31&thinsp;% and LV-OOA 53&thinsp;%). In contrast to winter, SV-OOA appears to result from a well-mixed type of aerosol that is linked to fast photochemical processes and the oxidation of primary traffic and biogenic emissions. Finally, LV-OOA presents a more regional character in summer, owing to the oxidation of OA over the period of a few days.</p

Mass and chemical composition of size-segregated aerosols (PM1, PM2.5, PM10) over Athens, Greece: Local versus regional sources

To identify the relative contribution of local versus regional sources of particulate matter (PM) in the Greater Athens Area (GAA), simultaneous 24-h mass and chemical composition measurements of size segregated particulate matter (PM1, PM2.5 and PM10) were carried out from September 2005 to August 2006 at three locations: one urban (Goudi, Central Athens, "GOU"), one suburban (Lykovrissi, Athens, "LYK") in the GAA and one at a regional background site (Finokalia, Crete, "FKL"). The two stations in the GAA exceeded the EU-legislated PM10 limit values, both in terms of annual average (59.0 and 53.6 μg m−3 for Lykovrissi and Goudi, respectively) and of 24-h value. High levels of PM2.5 and PM1 were also found at both locations (23.5 and 18.6 for Lykovrissi, while 29.4 and 20.2 μg m−3 for Goudi, respectively). Significant correlations were observed between the same PM fractions at both GAA sites indicating important spatial homogeneity within GAA. During the warm season (April to September), the PM1 ratio between GAA and FKL ranged from 1.1 to 1.3. On the other hand this ratio was significantly higher (1.6–1.7) during the cold season (October to March) highlighting the role of long-range transport and local sources during the warm and cold seasons respectively. Regarding the coarse fraction no seasonal trend was observed for both GAA sites with their ratio (GAA site/FKL) being higher than 2 indicating significant contribution from local sources such as soil and/or road dust. Chemical speciation data showed that on a yearly basis, ionic and crustal mass represent up to 67–70% of the gravimetrically determined mass for PM10 samples in the GAA and 67% for PM1 samples in LYK. The unidentified mass might be attributed to organic matter (OM) and elemental carbon (EC), in agreement with the results reported by earlier studies in central Athens. At all sites, similar seasonal patterns were observed for nss-SO42&minus;, a secondary compound, indicating significant contribution from regional sources in agreement with PM1 observations. The contribution of local sources at both GAA sites was also estimated by considering mass and chemical composition measurements at Finokalia as representative of the regional background. Particulate Organic Matter (POM) and EC, seemed to be the main contributor of the local PM mass within the GAA (up to 62% in PM1. Dust from local sources contributed also significantly to the local PM10 mass (up to 33%)

PM10 and PM2.5 composition over the Central Black Sea: origin and seasonal variability

Daily PM10 and PM2.5 samples were collected between April 2009 and July 2010 at a rural site (Sinop) situated on the coast of the Central Black Sea. The concentrations of PM10 and PM2.5 were 23.2 +/- 16.7 and 9.8 +/- 6.9 mu g m(-3), respectively. Coarse and fine filters were analyzed for Cl-, NO3 (-), SO4 (2-), C2O4 (2-), PO4 (3-), Na+, NH4 (+), K+, Mg2+, and Ca2+ by using ion chromatography. Elemental and organic carbon content in bulk quartz filters were also analyzed. The highest PM2.5 contribution to PM10 was found in summer with a value of 0.54 due to enhanced secondary aerosols in relation to photochemistry. Cl-, Na+, and Mg2+ illustrated their higher concentrations and variability during winter. Chlorine depletion was chiefly attributed to nitrate. Higher nssCa(2+) concentrations were ascribed to episodic mineral dust intrusions from North Africa into the region. Crustal material (31 %) and sea salt (13 %) were found to be accounted for the majority of the PM10. The ionic mass (IM), particulate organic matter (POM), and elemental carbon (EC) explained 13, 20, and 3 % of the PM10 mass, correspondingly. The IM, POM, and EC dominated the PM2.5 (similar to 74 %) mass. Regarding EU legislation, the exceeded PM2.5 values were found to be associated with secondary aerosols, with a particular dominance of POM. For the exceeded PM10 values, six of the events were dominated by dust while two and four of these exceedances were caused by sea salt and mix events, respectively

Particulate matter (PM10) in Istanbul: Origin, source areas and potential impact on surrounding regions

Water-soluble ions (Cl-, NO3-, SO42-, C2O4-, Na+, NH4+, K+, Mg2+,Ca2+), water soluble organic carbon (WSOC), organic and elemental carbon (OC, EC) and trace metals (Al, Ca, Ti, V. Cr, Mn, Fe, Ni, Cu, Zn, Cd and Pb) were measured in aerosol PM10 samples above the megacity of Istanbul between November 2007 and June 2009. Source apportionment analysis using Positive Matrix Factorization (PMF) indicates that approximately 80% of the PM10 is anthropogenic in origin (secondary, refuse incineration, fuel oil and solid fuel combustion and traffic). Crustal and sea salt account for 10.2 and 7.5% of the observed mass, respectively. In general, anthropogenic (except secondary) aerosol shows higher concentrations and contributions in winter. Mean concentration and contribution of crustal source is found to be more important during the transitional period due to mineral dust transport from North Africa. During the sampling period, 42 events exceeding the limit value of 50 mu g m(-3) are identified. A significant percentage (91%; n = 38) of these exceedances is attributed to anthropogenic sources. Potential Source Contribution Function analysis highlights that Istanbul is affected from distant sources from Balkans and Western Europe during winter and from Eastern Europe during summer. On the other hand, Istanbul sources influence western Black Sea and Eastern Europe during winter and Aegean and Levantine Sea during summer

Atmospheric Deposition of Macronutrients (Dissolved Inorganic Nitrogen and Phosphorous) onto the Black Sea and Implications on Marine Productivity*

Two-sized aerosol samples were obtained from a rural site located close to Sinop on the south coastline of the Black Sea. In addition, bulk deposition samples were collected at Varna, located on the west coastline of the Black Sea. Both aerosol and deposition samples were analyzed for the main macronutrients, NO3-, NH4+, and PO43-. The mean aerosol nitrate and ammonium concentrations were 7.1 +/- 5.5 and 22.8 +/- 17.8 nmol m(-3), respectively. The mean aerosol phosphate concentration was 0.69 +/- 0.31 nmol m(-3), ranging from 0.21 to 2.36 nmol m(-3). Interestingly, phosphate concentration over Sinop was substantially higher than those of most Mediterranean sites. Comparison of the atmospheric and riverine inputs for the Black Sea revealed that atmospheric dissolved inorganic nitrogen (DIN) only ranged between 4% and 13%, while the atmospheric dissolved inorganic phosphorus (DIP) fluxes had significantly higher contributions with values ranging from 12% to 37%. The molar N:P ratios in atmospheric deposition for Sinop and Varna were 13 and 14, respectively, both of which were lower than the Redfield ratio (16). The atmospheric molar N:P ratios over the Black Sea were considerably lower than those reported for riverine fluxes (41) and the Mediterranean region (more than 200). The atmospheric P flux can sustain 0.5%-5.2% of the primary production, whereas the N flux can sustain 0.4%-4.8% of the primary production. The contribution of the atmospheric flux may enhance by 2.6 when the new production is considered

Characterization of aerosols above the Northern Adriatic Sea: Case studies of offshore and onshore wind conditions

Aerosol particles in coastal areas result from a complex mixing between sea spray aerosols locally generated at the sea surface by the wind-waves interaction processes and a continental component resulting from natural and/or anthropogenic sources. This paper presents a physical and chemical analysis of the aerosol data acquired from May to September 2014 in the Adriatic Sea. Aerosol distributions were measured on the Acqua Alta platform located 15 km off the coast of Venice using two Particle Measuring System probes and a chemical characterization was made using an Ion Chromatography analysis (IC). Our aim is to study both the sea-spray contribution and the anthropogenic influence in the coastal aerosol of this Mediterranean region. To this end, we focus on a comparison between the present data and the aerosol size distributions measured south of the French Mediterranean coast. For air masses of marine origin transported by southern winds on the French coast and by the Sirocco in the Adriatic, we note a good agreement between the concentrations of super-micrometer aerosols measured in the two locations. This indicates a similar sea surface production of sea-spray aerosols formed by bubble bursting processes in the two locations. In contrast, the results show larger concentrations of submicron particles in the North-Western Mediterranean compared to the Adriatic, which result probably from a larger anthropogenic background for marine conditions. In contrast, for a coastal influence, the chemical analysis presented in the present paper seems to indicate a larger importance of the anthropogenic impact in the Northern Adriatic compared to the North-Western Mediterranean

Sugars in atmospheric aerosols over the Eastern Mediterranean

International audienceAerosol samples (PM10) were collected at Finokalia monitoring station in a remote area of Crete in the Eastern Mediterranean over a two-year period. They were analyzed for total organic carbon (OC), water-soluble organic carbon (WSOC), and the molecular distribution of sugars. WSOC comprised 45% of OC while the contribution of sugars to the OC and WSOC content in the PM10 particles averaged 3 ± 2% (n = 218) and 11 ± 6% (n = 132), respectively. The total concentration of sugars ranged between 6 and 334 ng m−3 with the two most abundant sugars over the two-year period being glucose and levoglucosan, contributing about 25% each to the total carbohydrate pool. Primary saccharides (glucose, fructose, and sucrose) peaked at the beginning of spring (21, 17, and 15 ng m−3, respectively), indicating significant contributions of bioaerosols to the total organic aerosol mass. On the other hand, higher concentrations of anhydrosugars (biomass burning tracers levoglucosan, mannosan, galactosan) were recorded in winter (19, 1.4, and 0.2 ng m−3 respectively) than in summer (9.1, 1.1, and 0.5 ng m−3 respectively). Levoglucosan was the dominant monosaccharide in winter (37% of total sugars) while the low concentration measured in summer (19% of total sugars) was probably due to the enhanced photochemical oxidation by hydroxyl (OH) radicals which impact anhydrosugars. Based on levoglucosan observations, biomass burning was estimated to contribute up to 13% to the annual average OC measured at Finokalia. Annual OC, WSOC, and carbohydrate dry deposition fluxes for the two-year sampling period were estimated at 414, 175, and 9 mg C m−2 y−1, respectively. Glucose and levoglucosan accounted for 34% and 2% of the total sugar fluxes. According to our estimations, atmospheric OC and WSOC inputs account for 0.70% and 0.71%, respectively of the carbon in the annual primary production in the Cretan Sea. Considering the entire Mediterranean, dry deposition of OC can provide at least 3 times more C than riverine inputs of Rhone. Carbohydrate dry deposition flux represents a small fraction of total carbon flux up to 0.04% of the C used for the primary production in the Cretan Sea, while this value is <0.01% for the entire Mediterranean. OC and WSOC contributions are in the order of 0.33% and 0.14% for the whole Mediterranean basin and further underline a minor contribution of the atmosphere in the carbon cycle of the Mediterranean Sea

Atmospheric acidification of mineral aerosols: A source of bioavailable phosphorus for the oceans

Primary productivity of continental and marine ecosystems is often limited or co-limited by phosphorus. Deposition of atmospheric aerosols provides the major external source of phosphorus to marine surface waters. However, only a fraction of deposited aerosol phosphorus is water soluble and available for uptake by phytoplankton. We propose that atmospheric acidification of aerosols is a prime mechanism producing soluble phosphorus from soil-derived minerals. Acid mobilization is expected to be pronounced where polluted and dust-laden air masses mix. Our hypothesis is supported by the soluble compositions and reconstructed pH values for atmospheric particulate matter samples collected over a 5-yr period at Finokalia, Crete. In addition, at least tenfold increase in soluble phosphorus was observed when Saharan soil and dust were acidified in laboratory experiments which simulate atmospheric conditions. Aerosol acidification links bioavailable phosphorus supply to anthropogenic and natural acidic gas emissions, and may be a key regulator of ocean biogeochemistry. © 2011 Author(s)