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1.
Influence of source specific black carbon production and meteorology on spatio-temporal distribution of black carbon concentration in Central-European basin
Luka Drinovec, Asta Gregorič, Irena Ježek, Rahela Žabkar, Jure Cedilnik, Griša Močnik, 2016, objavljeni povzetek znanstvenega prispevka na konferenci

Najdeno v: ključnih besedah
Povzetek najdenega: ...black carbon, source apportionment, planetary boundary layer...
Ključne besede: black carbon, source apportionment, planetary boundary layer
Objavljeno: 02.11.2016; Ogledov: 3012; Prenosov: 0
.pdf Polno besedilo (53,39 KB)

2.
Distinguishing source specific black carbon production from meteorologically driven temporal variability by means of 222Rn tracer
Asta Gregorič, Luka Drinovec, Irena Ježek, Janja Vaupotič, Longlong Wang, Maruška Mole, Samo Stanič, Griša Močnik, 2017, objavljeni povzetek znanstvenega prispevka na konferenci

Najdeno v: ključnih besedah
Povzetek najdenega: ...black carbon, source apportionment, radon, planetary boundary layer, lidar...
Ključne besede: black carbon, source apportionment, radon, planetary boundary layer, lidar
Objavljeno: 10.10.2017; Ogledov: 2362; Prenosov: 141
.pdf Polno besedilo (136,72 KB)

3.
Chemical characterization of PM2.5 and source apportionment of organic aerosol in New Delhi, India
Urs Baltensperger, Griša Močnik, Surender Singh, Suresh Tiwari, Deewan Bisht, Atul Srivastava, Suneeti Mishra, Navaneeth Thamban, Ashutosh Shukla, Vipul Lalchandani, Francesco Canonaco, Deepika Bhattu, Anna Tobler, Sachchida Tripathi, J. G. Slowik, Andre S. H. Prevot, 2020, izvirni znanstveni članek

Opis: Delhi is one of the most polluted cities worldwide and a comprehensive understanding and deeper insight into the air pollution and its sources is of high importance. We report 5 months of highly time-resolved measurements of non-refractory PM2.5 and black carbon (BC). Additionally, source apportionment based on positive matrix factorization (PMF) of the organic aerosol (OA) fraction is presented. The highest pollution levels are observed during winter in December/January. During that time, also uniquely high chloride concentrations are measured, which are sometimes even the most dominant NR-species in the morning hours. With increasing temperature, the total PM2.5 concentration decreases steadily, whereas the chloride concentrations decrease sharply. The concentrations measured in May are roughly 6 times lower than in December/January. PMF analysis resolves two primary factors, namely hydrocarbon-like (traffic-related) OA (HOA) and solid fuel combustion OA (SFC-OA), and one or two secondary factors depending on the season. The uncertainties of the PMF analysis are assessed by combining the random a-value approach and the bootstrap resampling technique of the PMF input. The uncertainties for the resolved factors range from ±18% to ±19% for HOA, ±7% to ±19% for SFC-OA and ±6 % to ±11% for the OOAs. The average correlation of HOA with eBCtr is R2 = 0.40, while SFC-OA has a correlation of R2 = 0.78 with eBCsf. Anthracene (m/z 178) and pyrene (m/z 202) (PAHs) are mostly explained by SFC-OA and follow its diurnal trend (R2 = 0.98 and R2 = 0.97). The secondary oxygenated aerosols are dominant during daytime. The average contribution during the afternoon hours (1 pm–5 pm) is 59% to the total OA mass, with contributions up to 96% in May. In contrast, the primary sources are more important during nighttime: the mean nightly contribution (22 pm–3 am) to the total OA mass is 48%, with contributions up to 88% during some episodes in April.
Najdeno v: ključnih besedah
Ključne besede: New Delhi, PM2.5, Source apportionment, PMF
Objavljeno: 20.07.2020; Ogledov: 483; Prenosov: 0
.pdf Polno besedilo (4,71 MB)

4.
Real-time characterization and source apportionment of fine particulate matter in the Delhi megacity area during late winter
Vipul Lalchandan, Varun Kumar, Anna Tobler, M.T. Navaneeth, Suneeti Mishra, J. G. Slowik, Deepika Bhattu, Pragati Rai, Rangu Satish, Dilip Ganguly, Tiwari Tiwari, Neeraj Rastogi, Tiwari Sashi, Griša Močnik, Andre S. H. Prevot, Sachchida Tripathi, 2021, izvirni znanstveni članek

Opis: National Capital Region (NCR) encompassing New Delhi is one of the most polluted urban metropolitan areas in the world. Real-time chemical characterization of fine particulate matter (PM1 and PM2.5) was carried out using three aerosol mass spectrometers, two aethalometers, and one single particle soot photometer (SP2) at two sites in Delhi (urban) and one site located ~40 km downwind of Delhi, during January-March, 2018. The campaign mean PM2.5 (NR-PM2.5 + BC) concentrations at the two urban sites were 153.8±109.4 μg.m-3 and 127.8±83.2 μg.m-3, respectively, whereas PM1 (NR-PM1 + BC) was 72.3 ± 44.0 μg.m-3 at the downwind site. PM2.5 particles were composed mostly of organics (43-44)% followed by chloride (14-17)%, ammonium (9-11)%, nitrate (9%), sulfate (8-10)%, and black carbon (11-16)%, whereas PM1 particles were composed of 47% organics, 13% sulfate as well as ammonium, 11% nitrate as well as chloride, and 5% black carbon. Organic aerosol (OA) source apportionment was done using positive matrix factorization (PMF), solved using an advanced multi-linear engine (ME-2) model. Highly mass-resolved OA mass spectra at one urban and downwind site were factorized into three primary organic aerosol (POA) factors including one traffic-related and two solid-fuel combustion (SFC), and three oxidized OA (OOA) factors. Whereas unit mass resolution OA at the other urban site was factorized into two POA factors related to traffic and SFC, and one OOA factor. OOA constituted a majority of the total OA mass (45-55)% with maximum contribution during afternoon hours ~(70-80)%. Significant differences in the absolute OOA concentration between the two urban sites indicated the influence of local emissions on the oxidized OA formation. Similar PM chemical composition, diurnal and temporal variations at the three sites suggest similar type of sources affecting the particulate pollution in Delhi and adjoining cities, but variability in mass concentration suggest more local influence than regional.
Najdeno v: ključnih besedah
Ključne besede: source apportionment, air pollution, particulate matter, Delhi
Objavljeno: 25.01.2021; Ogledov: 282; Prenosov: 0
.pdf Polno besedilo (2,92 MB)

5.
Evolution of organic aerosols in the atmosphere
J. H. Kroll, P. F. DeCarlo, J. David Allan, H. Coe, Katja Džepina, Jose L. Jimenez, M. R. Canagaratna, N. M. Donahue, A. S. H. Prevot, Q. Zhang, 2009, izvirni znanstveni članek

Opis: Organic aerosol (OA) particles affect climate forcing and human health, but their sources and evolution remain poorly characterized. We present a unifying model framework describing the atmospheric evolution of OA that is constrained by high–time-resolution measurements of its composition, volatility, and oxidation state. OA and OA precursor gases evolve by becoming increasingly oxidized, less volatile, and more hygroscopic, leading to the formation of oxygenated organic aerosol (OOA), with concentrations comparable to those of sulfate aerosol throughout the Northern Hemisphere. Our model framework captures the dynamic aging behavior observed in both the atmosphere and laboratory: It can serve as a basis for improving parameterizations in regional and global models.
Najdeno v: ključnih besedah
Povzetek najdenega: ...secondary organic aerosol, source apportionment, aerodyne aerosol mass spectrometer, global field...
Ključne besede: secondary organic aerosol, source apportionment, aerodyne aerosol mass spectrometer, global field measurements, laboratory experiments
Objavljeno: 11.04.2021; Ogledov: 56; Prenosov: 0
.pdf Polno besedilo (721,30 KB)

6.
Determination of Aethalometer multiple-scattering enhancement parameters and impact on source apportionment during the winter 2017/18 EMEP/ACTRIS/COLOSSAL campaign in Milan
Asta Gregorič, Dario Massabò, Griša Močnik, Paolo Prati, Martin Rigler, Luca Santagostini, Ezio Bolzacchini, Alice Corina Forello, Vera Bernardoni, Luca Ferrero, 2021, izvirni znanstveni članek

Opis: In the frame of the EMEP/ACTRIS/COLOSSAL campaign in Milan during winter 2018, equivalent black carbon measurements using the Aethalometer 31 (AE31), the Aethalometer 33 (AE33), and a Multi-Angle Absorption Photometer (MAAP) were carried out together with levoglucosan analyses on 12 h resolved PM2.5 samples collected in parallel. From AE31 and AE33 data, the loading-corrected aerosol attenuation coefficients (bATN) were calculated at seven wavelengths (λ, where λ values are 370, 470, 520, 590, 660, 880, and 950 nm). The aerosol absorption coefficient at 637 nm (babs_MAAP) was determined by MAAP measurements. Furthermore, babs was also measured at four wavelengths (405, 532, 635, 780 nm) on the 12 h resolved PM2.5 samples by a polar photometer (PP_UniMI). After comparing PP_UniMI and MAAP results, we exploited PP_UniMI data to evaluate the filter multiple-scattering enhancement parameter at different wavelengths for AE31 and AE33. We obtained instrument- and wavelength-dependent multiple-scattering enhancement parameters by linear regression of the Aethalometer bATN against the babs measured by PP_UniMI. We found significant dependence of the multiple-scattering enhancement parameter on filter material, hence on the instrument, with a difference of up to 30 % between the AE31 and the AE33 tapes. The wavelength dependence and day–night variations were small – the difference between the smallest and largest value was up to 6 %. Data from the different instruments were used as input to the so-called “Aethalometer model” for optical source apportionment, and instrument dependence of the results was investigated. Inconsistencies among the source apportionment were found fixing the AE31 and AE33 multiple-scattering enhancement parameters to their usual values. In contrast, optimised multiple-scattering enhancement parameters led to a 5 % agreement among the approaches. Also, the component apportionment “MWAA model” (Multi-Wavelength Absorption Analyzer model) was applied to the dataset. It was less sensitive to the instrument and the number of wavelengths, whereas significant differences in the determination of the absorption Ångström exponent for brown carbon were found (up to 22 %).
Najdeno v: ključnih besedah
Ključne besede: black carbon, filter photometer, Aethalometer, source apportionment
Objavljeno: 16.04.2021; Ogledov: 128; Prenosov: 0
.pdf Polno besedilo (1,95 MB)

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