1. Ambient carbonaceous aerosol levels in Cyprus and the role of pollution transport from the Middle EastAliki Christodoulou, Iasonas Stavroulas, Mihalis Vrekoussis, Maximillien Desservettaz, Michael Pikridas, Elie Bimenyimana, Jonilda Kushta, Matic Ivančič, Martin Rigler, Philippe Goloub, 2023, izvirni znanstveni članek Opis: Abstract. The geographical origin and source apportionment of submicron carbonaceous aerosols (organic aerosols, OAs, and black carbon, BC) have been investigated here for the first time, deploying high time-resolution measurements at an urban background site of Nicosia, the capital
city of Cyprus, in the eastern Mediterranean. This study covers a half-year
period, encompassing both the cold and warm periods with continuous
observations of the physical and chemical properties of PM1 performed
with an Aerosol Chemical Speciation Monitor (ACSM), an aethalometer,
accompanied by a suite of various ancillary offline and online measurements. Carbonaceous aerosols were dominant during both seasons (cold and warm periods), with a contribution of 57 % and 48 % to PM1, respectively, and exhibited recurrent intense nighttime peaks (> 20–30 µg m−3) during the cold period, associated with local domestic heating. The findings of this study show that high concentrations of sulfate (close to 3 µg m−3) were continuously recorded, standing among the highest ever reported for Europe and originating from the Middle East region. Source apportionment of the OA and BC fractions was performed using the
positive matrix factorization (PMF) approach and the combination of two
models (aethalometer model and multilinear regression), respectively. Our
study revealed elevated hydrocarbon-like organic aerosol (HOA)
concentrations in Nicosia (among the highest reported for a European urban
background site), originating from a mixture of local and regional
fossil fuel combustion sources. Although air masses from the Middle East had
a low occurrence and were observed mostly during the cold period, they were
shown to strongly affect the mean concentrations levels of BC and OA in
Nicosia during both seasons. Overall, the present study brings to our
attention the need to further characterize primary and secondary
carbonaceous aerosols in the Middle East, an undersampled region
characterized by continuously increasing fossil fuel (oil and gas) emissions
and extreme environmental conditions, which can contribute to photochemical
ageing. Ključne besede: PM1, BC, source apportionment, Cyprus, long range transport Objavljeno v RUNG: 10.05.2024; Ogledov: 12; Prenosov: 0 Celotno besedilo (5,55 MB) Gradivo ima več datotek! Več... |
2. Submicron aerosol pollution in Greater Cairo (Egypt) : a new type of urban haze?Aliki Christodoulou, Spiros Bezantakos, Efstratios Bourtsoukidis, Iasonas Stavroulas, Michael Pikridas, Konstantina Oikonomou, Minas Iakovides, Salwa K. Hassan, Mohamed Boraiy, Mostafa El-Nazer, 2024, izvirni znanstveni članek Ključne besede: megacity, submicron aerosols, urban haze, Greater Cairo, hygroscopic aerosols, ammonium chloride Objavljeno v RUNG: 10.05.2024; Ogledov: 12; Prenosov: 0 Celotno besedilo (7,34 MB) Gradivo ima več datotek! Več... |
3. A method for quantification of mineral dust in air based on optical absorption of particles concentrated by a virtual impactor and a device performing the said method : SI3783336 (T1), 2024-02-29Luka Drinovec, Griša Močnik, Iasonas Stavroulas, Spiros Bezantakos, Michael Pikridas, Florin Unga, Jean Sciare, 2024, patent Opis: The present invention belongs to the field of devices and methods for measurement of particle concentration, more precisely to the field of devices and methods for quantification of particles based on their physical characteristics, especially with the use of optical means. The invention relates to a method for determination of ambient mineral dust concentration based on optical absorption of particles concentrated by a virtual impactor as well as a device performing the said method. The method comprises the following steps:- Sampling air samples with particle size smaller than 1 µm (PM1) and sampling air samples with particle size up to 10 µm;- Concentrating the samples with particle sizes up to 10 µm with a virtual impactor;- Measuring optical absorption of collected samples at least one wavelength from UV to IR spectre, preferably from 370 to 950 nm, most preferably at 370 nm;- Subtracting the absorption of the samples with particle size smaller than 1 µm from the absorption of the sample concentrated by the virtual impactor. Ključne besede: dust, black carbon, aerosols Objavljeno v RUNG: 24.04.2024; Ogledov: 671; Prenosov: 2 Povezava na datoteko Gradivo ima več datotek! Več... |
4. Contribution of black carbon and desert dust to aerosol absorption in the atmosphere of the Eastern Arabian PeninsulaMohamed M. K. Mahfouz, Gregor Skok, Jean Sciare, Michael Pikridas, M. R. Alfarra, Shamjad Moosakutty, Bálint Alföldy, Matic Ivančič, Martin Rigler, Asta Gregorič, Rok Podlipec, Griša Močnik, 2024, izvirni znanstveni članek Opis: Discriminating the absorption coefficients of aerosol mineral dust and black carbon (BC) in different aerosol size fractions is a challenge because of BC's large mass absorption cross-section compared to dust. Ambient aerosol wavelength dependent absorption coefficients in supermicron and submicron size fractions were determined with a high time resolution. The measurements were performed simultaneously using identical systems at an urban and a regional background site in Qatar. At each site, measurements were taken by co-located Aethalometers, one with a virtual impactor (VI) and the other with a PM1 cyclone to respectively collect super-micron-enhanced and submicron fractions. The combined measurement of aerosol absorption and scattering coefficients enabled the particles to be classified based on their optical properties' wavelength dependence. The classification reveals the presence of BC internally/externally mixed with different aerosols. Helium ion microscopy images provided information concerning the extent of mineral dust in the submicron fraction. The determination of absorption coefficients during dust storms and non-dust periods was used to establish the absorption Ångström exponent for dust and BC. Non-parametric wind regression, potential source contribution function and back-trajectory analysis reveal major regional sources of desert dust associated with north-westerly winds and a minor local dust contribution. In contrast, major BC sources found locally were associated with south-westerly winds with a smaller contribution made by offshore emissions transported by north-easterly and easterly winds. The use of a pair of Aethalometers with VI and PM1 inlets separates contributions of BC and dust to the aerosol absorption coefficient. Ključne besede: aerosol absorption, black carbon, mineral dust, desert dust, Arabian Peninsula Objavljeno v RUNG: 29.02.2024; Ogledov: 446; Prenosov: 5 Celotno besedilo (18,90 MB) Gradivo ima več datotek! Več... |
5. Detection of mineral dust concentration in Mediterranean and Central Europe by measuring optical absorption of dust particlesMatic Ivančič, Irena Ježek, Martin Rigler, Asta Gregorič, Balint Alfoldy, Luka Drinovec, JEAN SCIARE, Michael Pikridas, FLORIN UNGA, Andrés Alastuey, Marco Pandolfi, Jesús Yus-Díez, Griša Močnik, 2020, prispevek na konferenci brez natisa Ključne besede: mineral dust, optical absorption, virtual impactor Objavljeno v RUNG: 22.11.2021; Ogledov: 1970; Prenosov: 0 Gradivo ima več datotek! Več... |
6. A new optical-based technique for real-time measurements of mineral dust concentration in PM10 using a virtual impactorLuka Drinovec, Jean Sciare, Iasonas Stavroulas, Spiros Bezantakos, Michael Pikridas, FLORIN UNGA, Chrysanthos Savvides, Bojana Višnjić, Maja Remškar, Griša Močnik, 2020, izvirni znanstveni članek Opis: Atmospheric mineral dust influences Earth’s radiative
budget, cloud formation, and lifetime; has adverse
health effects; and affects air quality through the increase of
regulatory PM10 concentrations, making its real-time quantification
in the atmosphere of strategic importance. Only
few near-real-time techniques can discriminate dust aerosol
in PM10 samples and they are based on the dust chemical
composition. The online determination of mineral dust using
aerosol absorption photometers offers an interesting and
competitive alternative but remains a difficult task to achieve.
This is particularly challenging when dust is mixed with
black carbon, which features a much higher mass absorption
cross section. We build on previous work using filter photometers
and present here for the first time a highly timeresolved
online technique for quantification of mineral dust
concentration by coupling a high-flow virtual impactor (VI)
sampler that concentrates coarse particles with an aerosol absorption
photometer (Aethalometer, model AE33). The absorption
of concentrated dust particles is obtained by subtracting
the absorption of the submicron (PM1) aerosol fraction
from the absorption of the virtual impactor sample (VIPM1
method). This real-time method for detecting desert
dust was tested in the field for a period of 2 months (April and
May 2016) at a regional background site of Cyprus, in the
Eastern Mediterranean. Several intense desert mineral dust
events were observed during the field campaign with dust
concentration in PM10 up to 45 μgm Ključne besede: aerosol absorption, mineral dust, on-line detection, air quality Objavljeno v RUNG: 20.07.2020; Ogledov: 2794; Prenosov: 0 Gradivo ima več datotek! Več... |