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During the 2013 Arctic campaign, direct measurements and size-segregated samplings of atmospheric aerosol were carried out from March to September at the Gruvebadet observatory in Ny-Ålesund (78°56′N, 11°56′E; Svalbard Islands). Continuous size distribution measurements (104 size classes) were performed both in the nano- (TSI-SMPS system) and micro-metric (TSI-APS device) range with a resolution of 10 min. Aerosol sampling was carried out on daily basis (PM10 fraction, 00:01–23:59 UTC) and with a 4-day resolution (four-stage cascade impactor). A back-trajectory analysis was performed for specific events to understand transport processes and possible source areas of aerosol reaching Ny-Ålesund. Aerosol samples were analyzed for ion composition (inorganic cations and anions, selected organic anions) by a three-chromatograph system after extraction in ultra-sonic bath. Special attention was spent in identifying and interpreting the seasonal pattern of natural and anthropic chemical markers. Sea spray aerosol was evenly distributed along all the sampling period with maxima related to wind speed. Its size distribution peaks in 1.0–2.5 or 2.5–10 µm, depending on the transport conditions and distance from source areas. Anthropic sulfate dominates the spring aerosol load (Arctic Haze), both in acidic form (H2SO4) and in partially or totally neutralized ammonium salts. Biogenic contributions, marked by methanesulfonic acid, are relatively relevant in late spring–early summer and are distributed in the finest aerosol fraction (<1.0 µm).

Daily PM10 aerosol samples were collected at the Gruvebadet observatory, Ny-Ålesund (Svalbard Islands), during the spring-summer 2014 Italian Arctic Campaign. A total of 136 samples were analysed for ion (inorganic anions and cations, selected organic anions) composition aiming to evaluate the seasonal pattern of sulfate, as a key component of the Arctic haze. Ionic balances indicated a strong sulfate seasonality with mean spring concentration about 1.5 times higher than that measured in summer. The spring and summer aerosol was almost neutral, indicating that ammonia was the major neutralizing agent for atmospheric acidic species. The linear regression between sulfate from potential acidic sources (non-sea salt sulfate and non-crustal sulfate) and ammonium indicated that the mean sulfate/ammonium ratio was intermediate between semi-(NH4HSO4) and complete ((NH4)2SO4) neutralization. Using sea-salt sodium as sea-spray marker, non-sea-salt calcium as crustal marker and methanesulfonic acid as biogenic marker, a detailed source apportionment for sulfate was carried out. The anthropogenic input (calculated as the differences between total sulfate and the sum of sea-salt, crustal and biogenic contributes) was found to be the most relevant contribution to the sulfate budget in the Ny-Ålesund aerosol in summer and, especially, in spring. In this last season, crustal, sea-salt, biogenic and anthropogenic sources accounted for 3.3, 12.0, 11.5 and 74.8 %, respectively.

Data centers (DC) are responsible for a large global electricity usage mainly due to their cooling systems. Air conditioning (AC) costs could be reduced using a Direct Free Cooling (DFC) system which uses outside air to directly cool the information technology (IT). However this approach involves the risk to introduce outdoor aerosol which can become electrically conductive if the surrounding air reaches the aerosol Deliquescence Relative Humidity (DRH), thus damaging electronic equipment. In this work we present a study aimed to increase DC energy efficiency, whilst at the same time preventing aerosol corrosion. The study was conducted in Italy at Sannazzaro de' Burgondi (SdB, Po Valley), to specifically optimize the operating conditions of a DC designed for the Italian National Hydrocarbon Institution (ENI) (5,200 m2 of IT installed, 30 MW). Aerosol number size distribution was monitored and allowed to estimate the aerosol level entering the DC; moreover aerosol chemical composition was investigated and allowed to estimate the aerosol free acidity and the aerosol DRH using the thermodynamic Aerosol Inorganic Model (E-AIM). E-AIM output were validated through laboratory tests, using an Aerosol Exposure Chamber, and through a comparison among "wet" and "dry" aerosol size distribution measured at SdB. From these data it was possible to design the filtering system of the DC and to estimate the outdoor air supply time, by DFC, and thus to estimate the energy consumption of the DC. A potential energy savings of 60% was estimated compared to a traditional AC cooling system with a potential energy saving of 7358 kWh and 2.67 t of CO2 (for 1 kW of installed IT)

Data centers (DC) are responsible for a large global electricity usage mainly due to their cooling systems. Air conditioning (AC) costs could be reduced using a Direct Free Cooling (DFC) system which uses outside air to directly cool the information technology (IT). However this approach involves the risk to introduce outdoor aerosol which can become electrically conductive if the surrounding air reaches the aerosol Deliquescence Relative Humidity (DRH), thus damaging electronic equipment. In this work we present a study aimed to increase DC energy efficiency, whilst at the same time preventing aerosol corrosion. The study was conducted in Italy at Sannazzaro de' Burgondi (SdB, Po Valley), to specifically optimize the operating conditions of a DC designed for the Italian National Hydrocarbon Institution (ENI) (5,200 m2 of IT installed, 30 MW). Aerosol number size distribution was monitored and allowed to estimate the aerosol level entering the DC; moreover aerosol chemical composition was investigated and allowed to estimate the aerosol free acidity and the aerosol DRH using the thermodynamic Aerosol Inorganic Model (E-AIM). E-AIM output were validated through laboratory tests, using an Aerosol Exposure Chamber, and through a comparison among "wet" and "dry" aerosol size distribution measured at SdB. From these data it was possible to design the filtering system of the DC and to estimate the outdoor air supply time, by DFC, and thus to estimate the energy consumption of the DC. A potential energy savings of 60% was estimated compared to a traditional AC cooling system with a potential energy saving of 7358 kWh and 2.67 t of CO2 (for 1 kW of installed IT)

In this work, aerosol size distribution measurements along with individual particle analyses were performed along the vertical profile in the atmosphere, to shed some light on the dynamics of evolution of aerosol properties upon a basin valley. The case study is the Terni basin, one of the most polluted urban and industrial sites in central Italy. Aerosol vertical profile measurements were performed using a helium-filled tethered balloon equipped with an optical particle counter (OPC), a miniaturized cascade impactor with particle collection filter, and a portable meteorological station. Combined OPC number size measurements and single particle analyses by scanning electron microscopy were employed to reconstruct the pattern and evolution of aerosol properties over the basin. Moreover, the CHIMERE chemistry-transport model was applied over a selected computing domain to obtain a general overview of the driving forces of the aerosol dynamics. Scanning electron microscopy methods along with chemical transport modeling revealed distinct distributions of number, size and geochemical properties of different particles classes in the aerosols. These reflect distinct behaviours and spatial/temporal evolution of the constituent particles, along with the common occurrence of dust inputs from regional to long range sources (e.g., Saharan dust inputs). All these features have to be taken into consideration when approaching the modeling of atmospheric processes, particularly in basin valleys located in Central and Southern Italy where the influence of Saharan dust outbreaks is more pronounced

This study presents the results of measurement of PAH (Polyciclic Aromatic Hydrocarbons) concentrations in the urban atmosphere in Milan. Analysis have been led on samples collected in two sites: the first representing the typical medium-urban traffic condition of the city (Messina Street), the second representative of high-level traffic pollution (a road tunnel near the Central Railway Station). Greater attention has been focused on the PAH content in the PM 2.5 rather than in the PM 10 fraction, as it seems this type of pollutant are mostly (80-90%) shared out in the fine atmospheric particulate matter. The association of PAH presence in different dimensional classes is compared to data collected by other studies found in literature. The daily trend of PAH concentration has also been correlated to the traffic volumes recorded in the sites. Furthermore, data on the principal inorganic compounds (sulfate, nitrate and ammonium) analyzed in the samples, and the description of their possible presence in the atmospheric paniculate matter is given.