Size-segregated mass distributions of aerosols over Eastern Mediterranean: seasonal variability and comparison with AERONET columnar size-distributions

Abstract

Abstract. This work provides long-term (2004)(2005)(2006) size segregated measurements of aerosol mass at a remote coastal station in the southern Europe, with the use of size-selective samplings (SDI impactor). Seven distinct modes were identified in the range 0-10 µm and the dominant were the "Accumulation 1" (0.25-0.55 µm) and the "Coarse 2" (3-7 µm) modes. The seasonal characteristics of each mode were thoroughly studied and different sources for submicron and supermicron particles were identified, the first being related to local/regional and transported pollution with maximum in summer and the latter to dust from deserted areas in Northern Africa maximizing in spring. On average, PM 2.5 and PM 1 accounted for 60% and 40% of PM 10 mass, respectively.The representativity of the ground-based measurements for the total column was also investigated by comparing the measured aerosol mass distributions with the AERONET volume size distribution data. Similar seasonal patterns were revealed and AERONET was found adequate for the estimation of background levels of both fine and coarse particles near surface, with certain limitations in the case of pollution or dust abrupt episodes due to its low temporal coverage.

Mass and chemical composition of size-segregated aerosols (PM<sub>1</sub>, PM<sub>2.5</sub>, PM<sub>10</sub>) over Athens, Greece: local versus regional sources

“…As in FKL, PM 1 /PM 10 ratios at the two GAA stations reveal also the existence of two data pairs corresponding to dust and non-dust events with PM 1 /PM 10 ratios similar to those observed at FKL (1:1.1 to 1:2.1 for non-dust, and 1:11 to 1:5.8 for dust events, for Gou and LYK respectively). These results provide further support to the conclusion drawn by Gerasopoulos et al (2007) and Querol et al (2009) that in the Mediterranean due to high crustal content of PM, PM 1 rather than PM 2.5 , monitoring can provide a more accurate estimation of the anthropogenic fraction. On that account, in the following discussion, fine and coarse fractions will correspond to PM 1 and PM 10−1 respectively.…”

Aerosol microphysical retrievals from precision filter radiometer direct solar radiation measurements and comparison with AERONET

“…The coarse mode is centred at r = 5.1 µm but exhibits a much broader distribution of particle volumes spanning radial bins from r = 1.3 to 8.7 µm. This size range is typical for dust aerosols in the Mediterranean Basin (Gerasopoulos et al, 2007). On the days where the dust influence is most pronounced, the distribution of coarse particles appears to be skewed towards smaller radius particles.…”

“…The AERONET dust product is expected to be further enhanced in the new GARRLiC algorithm, which combines sun-photometric measurements with lidar measurements (Lopatin et al, 2013). Validation studies comparing column-averaged volume size distributions obtained from sun-photometer measurements with direct in situ measurements from aircraft as well as at the surface (Haywood et al, 2011;Toledano et al, 2011;Gerasopoulos et al, 2007) are key to helping systematically validate microphysical inversion products (IPCC AR5, 2013, Chapter 7, p. 603) from AERONET.…”

Solar dimming and brightening over Thessaloniki, Greece, and Beijing, China

“…These results, which can have significant climatological consequences (IPCC, 2007), were derived using the SW solar irradiance. Until now, no study has included estimates based on ultraviolet (UV)‐A irradiances, which are much more sensitive to aerosols, a major factor affecting the downwelling solar radiation, which correlates well with anthropogenic activities (Papayannis et al, 1998; Zerefos et al, 1998; Zerefos et al, 2000; Balis et al, 2003; Gerasopoulos et al, 2003; Fotiadi et al, 2006; Gerasopoulos et al, 2006; Gerasopoulos et al, 2007; Kalivitis et al, 2007).…”