X-ray Spectroscopic Quantification of Phosphorus Transformation in Saharan Dust during Trans-Atlantic Dust Transport.

Saharan dust is an important phosphorus (P) supply to remote and oligotrophic parts of the oceans and American lowland tropical rainforests. Phosphorus speciation in aeolian dust ultimately controls the release and bioavailability of P after dust deposition, but the speciation in Saharan dust and its change during the trans-Atlantic transport remains unclear. Using P K-edge X-ray absorption near edge structure (XANES) spectroscopy, we showed that with increasing dust traveling distance from the Sahara Desert to Cape Verde and to Puerto Rico, about 570 and 4000 km, respectively, the proportion of Ca-bound P (Ca-P), including both apatite and non-apatite forms, decreased from 68-73% to 50-71% and to 21-37%.

Polycyclic aromatic hydrocarbons and their derivatives (nitro-PAHs, oxygenated PAHs, and azaarenes) in PM from Southern European cities.

Atmospheric particulate matter (PM) samples were collected over two one month periods during winter and summer in three Southern European cities (Oporto - traffic site, Florence - urban background, Athens - suburban). Concentrations of 27 polycyclic aromatic hydrocarbons (PAHs), 15 nitro-PAHs (NPAHs), 15 oxygenated-PAHs (OPAHs) and 4 azaarenes (AZAs) were determined. On average, the winter-summer concentrations of ΣPAHs were 16.

Hydrocarbons in particulate samples from wildfire events in central Portugal in summer 2010.

In summer 2010, twenty eight (14 PM samples plus 14 samples PM) smoke samples were collected during wildfires that occurred in central Portugal. A portable high-volume sampler was used to perform the sampling, on quartz fibre filters of coarse (PM) and fine (PM) smoke samples. The carbonaceous content (elemental and organic carbon) of particulate matter was analysed by a thermal-optical technique.

A one-year record of carbonaceous components and major ions in aerosols from an urban kerbside location in Oporto, Portugal.

PM2.5 aerosol samples were collected from January 2013 to January 2014 on the kerbside of a major arterial route in the city of Oporto, Portugal, and later analyzed for carbonaceous fractions and water soluble ions. The average concentrations of organic carbon (OC), elemental carbon (EC) and water soluble organic carbon (WSOC) in the aerosol were 6.

Elements and polycyclic aromatic hydrocarbons in exhaust particles emitted by light-duty vehicles.

The main purpose of this work was to evaluate the chemical composition of particulate matter (PM) emitted by eight different light-duty vehicles. Exhaust samples from petrol and diesel cars (Euro 3 to Euro 5) were collected in a chassis dynamometer facility. To simulate the real-world driving conditions, three ARTEMIS cycles were followed: road, to simulate a fluid traffic flow and urban with hot and cold starts, to simulate driving conditions in cities.

Wet deposition of particulate carbon to the Central North Atlantic Ocean.

Elemental carbon (EC) and water-insoluble organic carbon (WIOC) concentrations were measured in wet-only precipitation samples collected on Terceira Island (Azores, Portugal) between December 2009 and October 2010, to investigate temporal variations, source regions and wet deposition fluxes. The global volume-weighted average (vwa) concentrations were 134 ± 19 μgC L(-1) for WIOC and 15.0 ± 1.

Indoor and outdoor suspended particulate matter and associated carbonaceous species at residential homes in northwestern Portugal.

Particulate matter with an aerodynamic diameter equal to or less than 10 μm (PM10), organic carbon (OC) and elemental carbon (EC) concentrations were measured simultaneously in the indoor and outdoor air of 4 residences located in urban and sub-urban areas in northwestern Portugal. The residences were studied with occupants. One residence was also studied without any indoor activity, taking advantage of the fact that the occupants had moved into a new home.

Convergence of potential net ecosystem production among contrasting C3 grasslands.

Metabolic theory and body size constraints on biomass production and decomposition suggest that differences in the intrinsic potential net ecosystem production (NEPPOT ) should be small among contrasting C3 grasslands and therefore unable to explain the wide range in the annual apparent net ecosystem production (NEPAPP ) reported by previous studies. We estimated NEPPOT for nine C3 grasslands under contrasting climate and management regimes using multiyear eddy covariance data. NEPPOT converged within a narrow range, suggesting little difference in the net carbon dioxide uptake capacity among C3 grasslands.

Size distribution of polycyclic aromatic hydrocarbons in a roadway tunnel in Lisbon, Portugal.

Atmospheric aerosols of four aerodynamic size ranges were collected using high volume cascade impactors in an extremely busy roadway tunnel in Lisbon (Portugal). Dust deposited on the tunnel walls and guardrails was also collected. Average particle mass concentrations in the tunnel atmosphere were more than 30times higher than in the outside urban background air, revealing its origins almost exclusively from fresh vehicle emissions.

Emission of trace gases and organic components in smoke particles from a wildfire in a mixed-evergreen forest in Portugal.

On May 2009, both the gas and particulate fractions of smoke from a wildfire in Sever do Vouga, central Portugal, were sampled. Total hydrocarbons and carbon oxides (CO(2) and CO) were measured using automatic analysers with flame ionisation and non-dispersive infrared detectors, respectively. Fine (PM(2.

Determination of saccharides in atmospheric aerosol using anion-exchange high-performance liquid chromatography and pulsed-amperometric detection.

An improved method is described for the quantification of primary sugars, sugar alcohols and anhydrosugars in atmospheric aerosols, making use of separation by high-performance anion-exchange chromatography (HPAEC) with pulsed amperometric detection (PAD). Quartz fibre filters from high-volume samplers were extracted with water and the extract injected directly. Repeatability is typically 4% RSD, for e.

Atmospheric carbonaceous aerosols over grasslands of central Europe and a Boreal forest.

A labour-intensive analytical technique was applied to atmospheric particulate matter samples collected in a German urban/industrial influenced grassland location (Melpitz) and in a Finnish forest area (Hyytiälä) in order to achieve a detailed chemical speciation of the organic content. The representative nature of the solvent and water-extractable fractions was determined. The organic compounds identified in the solvent extracts are represented by primary compounds with both anthropogenic and biogenic origin, which mainly derive from the vegetation waxes and from petrogenic sources.