Characterization of PM<sub>10</sub> sources in the central Mediterranean

Abstract

Abstract. The Mediterranean Basin atmosphere is influenced by both strong natural and anthropogenic aerosol emissions and is also subject to important climatic forcings. Several programs have addressed the study of the Mediterranean basin; nevertheless important pieces of information are still missing. In this framework, PM10 samples were collected on a daily basis on the island of Lampedusa (35.5° N, 12.6° E; 45 m a.s.l.), which is far from continental pollution sources (the nearest coast, in Tunisia, is more than 100 km away). After mass gravimetric measurements, different portions of the samples were analyzed to determine the ionic content by ion chromatography (IC), the soluble metals by inductively coupled plasma atomic emission spectrometry (ICP-AES), and the total (soluble + insoluble) elemental composition by particle-induced x-ray emission (PIXE). Data from 2007 and 2008 are used in this study. The Positive Matrix Factorization (PMF) model was applied to the 2-year long data set of PM10 mass concentration and chemical composition to assess the aerosol sources affecting the central Mediterranean basin. Seven sources were resolved: sea salt, mineral dust, biogenic emissions, primary particulate ship emissions, secondary sulfate, secondary nitrate, and combustion emissions. Source contributions to the total PM10 mass were estimated to be about 40 % for sea salt, around 25 % for mineral dust, 10 % each for secondary nitrate and secondary sulfate, and 5 % each for primary particulate ship emissions, biogenic emissions, and combustion emissions. Large variations in absolute and relative contributions are found and appear to depend on the season and on transport episodes. In addition, the secondary sulfate due to ship emissions was estimated and found to contribute by about one-third to the total sulfate mass. Results for the sea-salt and mineral dust sources were compared with estimates of the same contributions obtained from independent approaches, leading to an estimate of the water content bound to the sea salt in the marine source.

Constraining the ship contribution to the aerosol of the central Mediterranean

“…Nitrate concentrations, although relatively high at both sites, are in agreement with the long term measurements performed at Lampedusa (e.g. Calzolai et al, 2015) and with data from other remote sites in the western (Mallorca; e.g. Simo et al, 1991) and eastern Mediterranean (Finokalia; e.g.…”

“…At the station for climate Observations, which is located on a plateau 45 m a.s.l on the northeastern coast of Lampedusa, continuous observations of aerosol properties Becagli et al, 2013;Marconi et al, 2014;Calzolai et al, 2015;Sellitto et al, 2017), aerosol radiative effects (e.g. Casasanta et al, 2011; and other climatic parameters are carried out.…”

“…Casasanta et al, 2011; and other climatic parameters are carried out. PM 10 is routinely sampled on a daily basis at LMP (Becagli et al, 2013;Marconi et al, 2014;Calzolai et al, 2015) by using a low-volume dual-channel sequential sampler (HYDRA FAI Instruments) equipped with two PM 10 sampling heads, operating in accord with UNI EN12341. For the intensive ChArMEx campaign, samples were collected at 12 h resolution (08:00-20:00 and 20:00-08:00 LT-local time) from 1 June to 3 August 2013.…”

XRF characterization and source apportionment of PM10 samples collected in a coastal city

“…It increases PM10 mass by 11.9% (3.7 μg/m 3 ) per year. The Cl/Na ratio measured in the factor is equal to 1.9 that is very close to the 1.8 value of the fresh sea salt . Fresh sea salt is mainly found on fresh particles and has no seasonal trend.…”

AIRUSE-LIFE +: estimation of natural source contributions to urban ambient air PM<sub>10</sub> and PM<sub>2. 5</sub> concentrations in southern Europe – implications to compliance with limit values

“…Net African dust load was quantified for each day forecasted as potential dust event by at least one of the above-mentioned models, as the observed increase in concentration with respect to the calculated moving average for that day (representative of background concentration not affected by dust transport). Sea salt (ss) was calculated based on major sea-salt components (Cl and Na) and typical elemental ratios for sea water (Mg/Na, K/Na, Ca/Na and SO 2− 4 /Na) and the Earth's crust (Na/Al) (Calzolai et al, 2015): …”