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Changes in Composition of Submicron Particular Matter of Atmospheric Aerosol During 2013 New Year´s Celebration
Kubelová, Lucie ; Vodička, Petr ; Schwarz, Jaroslav
In this work we investigated rapid changes in chemical composition of PM1 fraction during the celebrations of New Year 2013. The measurements were carried out at the urban background site Prague-Suchdol. The compact Time-of-Flight Aerosol Mass Spectrometer (c-ToF-AMS, Aerodyne), Drewnick et al. (2005), was used to analyze highly time-resolved samples of non-refractory aerosol components. We focused on four episodes with significantly elevated total aerosol mass concentration. We assume that the increased concentrations are due to: smoke plume from wood burning in Episode 1, fireworks in Episode 2, arrival of another air mass in Episode 3, and an uncategorized source of poly-aromatic hydrocarbons in Episode 4. The highest attention was given to the time interval between 00:20 and 2:20 a.m. on the New Year (marked in Figure 1 as Episode 2) as the aerosol composition was significantly affected by the occurring annual celebrations. In this period, the most significant increase in mass concentration was observed by sulfate, chlorides, and potassium (involved in the mass spectra for fragment 39). At the same time, nitrate and ammonium were unaffected. Those trends were compared to other measurements with c-ToF-AMS during annual celebrations, Drewnick et al.
Fulltext: content.csg -  PDF
Plný tet: SKMBT_C22013101814584 - PDF
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Comparability of Methods to Measure Black and Elemental Carbon in Two European Urban Areas - Site and Seasonal Similarities and Differences
Hitzenberger, R. ; Schwarz, Jaroslav ; Aschauer, I. ; Haindl, R. ; Ludwig, W. ; Wagner, R. ; Wonaschuetz, A. ; Zecha, G. ; Ševčíková, Irena ; Vodička, Petr ; Zíková, Naděžda ; Ždímal, Vladimír
The goal of the current study is to investigate whether similar conversion factors are applicable at the sites and whether the conversion factors obtained earlier (i.e. ca. 10 years ago) for Vienna are still valid or whether changing source conditions have resulted in shifts of the carbonaceous fractions of the aerosol that would require a new set of conversion factors.
Fulltext: content.csg - PDF
Plný tet: SKMBT_C22013091712210 - PDF
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Does oxidation make the organic aerosol coatings more hydrophilic? Insight from molecular dynamics study of oxidized surfactant monolayers
Roeselová, Martina ; Khabiri, Morteza ; Cwiklik, Lukasz
Organic compounds are ubiquitous in atmospheric aerosols. The morphology and structure of the organic phase affect the optical properties of the aerosols, their heterogeneous reactivity as well as their ability to nucleate cloud droplets and ice particles. It is commonly assumed that atmospheric oxidative ageing of the organic material, leading to the formation of polar groups such as carbonyl (=O), hydroxyl (-OH) and carboxylic acid (-COOH), will render the aerosol particle surfaces increasingly more hydrophilic, hence, able to take up more water. Field measurements have shown that a large fraction of the organic material found in aerosols are surface active compounds, such as fatty acids and lipids(Tervahattu, 2002 and 2005). An inverted micelle structure, with an aqueous core surrounded by an organic surfactant layer, has thus been proposed for aqueous aerosols, both marine and continental (Donaldson, 2006). While recent experiments suggest the existence of more complex structures, such as organic inclusions and surfactant lenses (Dennis-Smither, 2012), a monolayer (ML) of surface active organics on an aqueous subphase (the so called Langmuir monolayers) represents the basic model system used in laboratory studies aimed at elucidating the effect of oxidative processes on structural properties of organic coatings on aerosol particles. In our previous work, we used molecular dynamics computer simulations to study the structure and stability of oxidized phospholipid MLs (Khabiri, 2012). In this contribution, we employed the molecular dynamics simulation technique to investigate – with atomistic resolution – structural changes occuring in a fatty acid ML upon moderate degree of oxidation.
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Porovnání ultrajemných atmosférických aerosolů v Praze a Budapešti
Matějková, Daniela ; Borsós, T. ; Ždímal, Vladimír ; Salma, I. ; Schwarz, Jaroslav ; Smolík, Jiří
Data measured in Prague suburbs and Budapest city center have been compared in the time period from November 1, 2008 until August 31, 2009 in the size range from 10 nm to 1 µm. Total average particle number concentrations were calculated, 6.8×103 particles/cm3 in Prague, and 1.3×104 particles/cm3 in Budapest. The size distributions were mostly bimodal with the mode located either in the Aitken (25–100 nm) or in the accumulation mode range (> 100 nm). When new particle formation started in the atmosphere, the nucleation mode (< 25 nm) appeared growing from the lowest detectable sizes upwards.
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Chemická velikostní distribuce předměstského aerosolu vzorkovaného v Praze 2008 s použitím vlhkostně kontrolovaných inletů
Štefancová, Lucia ; Schwarz, Jaroslav ; Maenhaut, W. ; Chi, X. ; Smolík, Jiří
Ambient aerosol sampling was provided using two humidity controlled inlets. Dry particles were retained upon 15%RH, whereas wet particles were collected at 85-90%RH. 11 intakes was done during winter campaign and 10 during summer one. Mean mass concentration obtained for winter than for summer. In both cases the value did not exceed EU annual limit for PM10. Chemical composition was determined by ion chromatography. The most abundant were hygroscopic ions as NH4+, SO42-, NO3-. Their particle growth due to high RH was observed on their mass-size distribution. NH4+ cation has good correlation with SO42-and NO3- anions. Mean mass concentrations of WSOC, EC and OC were determined for both campaigns. WSOC value in winter was 0.80 µg/m3and 0.78µg/m3 in summer.
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