11. Rolling vs. seasonal PMF : real-world multi-site and synthetic dataset comparisonMarta Via, Gang Chen, Francesco Canonaco, Kaspar Rudolf Daellenbach, Benjamin Chazeau, Hasna Chebaicheb, Jianhui Jiang, Hannes Keernik, Chunshui Lin, Nicolas Marchand, 2022, original scientific article Abstract: Abstract. Particulate matter (PM) has become a major concern in terms of human health
and climate impact. In particular, the source apportionment (SA) of organic
aerosols (OA) present in submicron particles (PM1) has gained relevance
as an atmospheric research field due to the diversity and complexity of its
primary sources and secondary formation processes. Moreover, relatively
simple but robust instruments such as the Aerosol Chemical Speciation
Monitor (ACSM) are now widely available for the near-real-time online
determination of the composition of the non-refractory PM1. One of the
most used tools for SA purposes is the source-receptor positive matrix
factorisation (PMF) model. Even though the recently developed rolling PMF technique has
already been used for OA SA on ACSM datasets, no study has assessed its
added value compared to the more common seasonal PMF method using a practical
approach yet. In this paper, both techniques were applied to a synthetic
dataset and to nine European ACSM datasets in order to spot the main output
discrepancies between methods. The main advantage of the synthetic dataset
approach was that the methods' outputs could be compared to the expected
“true” values, i.e. the original synthetic dataset values. This approach
revealed similar apportionment results amongst methods, although the
rolling PMF profile's adaptability feature proved to be advantageous, as it
generated output profiles that moved nearer to the truth points. Nevertheless,
these results highlighted the impact of the profile anchor on the solution,
as the use of a different anchor with respect to the truth led to
significantly different results in both methods. In the multi-site study,
while differences were generally not significant when considering year-long
periods, their importance grew towards shorter time spans, as in intra-month
or intra-day cycles. As far as correlation with external measurements is
concerned, rolling PMF performed better than seasonal PMF globally for the ambient
datasets investigated here, especially in periods between seasons. The results of this
multi-site comparison coincide with the synthetic dataset in terms of
rolling–seasonal similarity and rolling PMF reporting moderate improvements. Altogether, the
results of this study provide solid evidence of the robustness of both
methods and of the overall efficiency of the recently proposed rolling PMF
approach.
Keywords: particulate matter, synthetic dataset comparison, source apportionment, organic aerosols
Published in RUNG: 10.05.2024; Views: 257; Downloads: 4
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12. Increase in secondary organic aerosol in an urban environment : Increase in secondary organic aerosol in an urban environmentMarta Via, Maria Cruz Minguillon, Cristina Reche, Xavier Querol, Andrés Alastuey, 2021, original scientific article Abstract: The evolution of fine aerosol (PM1) species as well as the contribution of potential sources to the total organic aerosol (OA) at an urban background site in Barcelona, in the western Mediterranean basin (WMB) was investigated. For this purpose, a quadrupole aerosol chemical speciation monitor (Q-ACSM) was deployed to acquire real-time measurements for two 1-year periods: May 2014–May 2015 (period A) and September 2017–October 2018 (period B). Total PM1 concentrations showed a slight decrease (from 10.1 to 9.6 μgm�3 from A to B), although the relative contribution of inorganic and organic compounds varied significantly. Regarding inorganic compounds, SO42- , black carbon(BC) and NH4+ showed a significant decrease from period
A to B (21 %, 18% and 9 %, respectively), whilst NO3- concentrations were higher in B (8 %). Source apportionment
revealed OA contained 46% and 70% secondary OA (SOA) in periods A and B, respectively. Two secondary oxygenated OA sources (OOA) were differentiated by their oxidation status (i.e. ageing): less oxidized (LO-OOA) and more oxidized (MO-OOA). Disregarding winter periods, when LO-OOA production was not favoured, LO-OOA transformation into MO-OOA was found to be more effective in
period B. The lowest LO-OOA-to-MO-OOA ratio, excluding winter, was in September–October 2018 (0.65), implying an accumulation of aged OA after the high temperature and solar radiation conditions in the summer season. In addition to temperature, SOA (sum of OOA factors) was enhanced by exposure to NOx-polluted ambient and other pollutants, especially to O3 and during afternoon hours. The anthropogenic primary OA sources identified, cooking-related
OA (COA), hydrocarbon-like OA (HOA), and biomass burning OA (BBOA), decreased from period A to B in both absolute concentrations and relative contribution (as a whole, 44% and 30 %, respectively). However, their concentrations and proportion to OA grew rapidly during highly polluted episodes. The influence of certain atmospheric episodes on OA sources was also assessed. Both SOA factors were boosted with long- and medium-range circulations, especially those coming from inland Europe and the Mediterranean (triggering mainly MO-OOA) and summer breeze-driven regional circulation (mainly LO-OOA). In contrast, POA was
enhanced either during air-renewal episodes or stagnation anticyclonic events.
Keywords: aerosol, organic aerosol, source apportionment, PM1, particulate matter
Published in RUNG: 10.05.2024; Views: 253; Downloads: 3
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13. Composition and source apportionment of PM10 in an Alpine valley influenced by a cement plant : lecture at the European aerosol conference, EAC2023, Malaga, Spain, 3. 9. 2023Kristina Glojek, Katja Džepina, Griša Močnik, 2023, unpublished conference contribution Keywords: air pollution, extensive PM characterization, positive matrix factorization (PMF), new source identification
Published in RUNG: 23.02.2024; Views: 679; Downloads: 2
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14. Identification and detailed characterization of ▫$PM_10$▫ sources in an Alpine valley influenced by a cement plantKristina Glojek, Katja Džepina, Griša Močnik, 2023, published scientific conference contribution abstract Abstract: The contribution of traffic and wood burning to particulate matter (PM) across the Alps is widely recognized and studied (Herich et al., 2014 and references therein; Glojek et al., 2020). However, studies on valleys with cement production are scarce (Kim et al., 2003; Rovira et al., 2018) despite its large PM emissions and potential toxic properties (Erik et al., 2022; Weinbruch et al., 2023). We aim to identify and characterize sources’ contribution to the complex mixture of carbonaceous and mineral PM10 in a representative Alpine valley.
Quartz filter samples of PM10 were collected daily from December 2020 to December 2021 and analyzed using different chemical techniques. In the same period equivalent black carbon (eBC) measurements were taken with the Aethalometer AE43. The measured species were analyzed using Positive Matrix Factorization (PMF) model (EPA PMF 5.0) with newly added tracers, i. e. source-specific eBC (Sandradewi et al., 2008) and organic species (2-MT, 3-MBTCA, phtalic acid, MSA and oxalate). The final PMF results were compared to online PMF-factors (SoFi Pro) derived from PM10 and PM2.5 elemental measurements (Cooper Xact 625i).
Ten factors were identified at the site, including commonly detected biomass burning, traffic, nitrate- and sulfate-rich, aged sea salt and mineral dust. With the added additional organic traces, primary biogenic and secondary oxidation were recognized as well. In addition, two unusual factors were disclosed, contributing 10% to annual PM10. Namely, Cl-rich and a mineral dust-rich factor, which we name the cement kiln factor. We associate these two factors to different processes in the cement plant.
The outputs of the study provide vital information about the influence of cement production on PM10 concentrations in complex environments and are useful for PM control strategies and actions.
Keywords: PM pollution, carbonaceous aerosols, source apportionment, industry
Published in RUNG: 10.01.2024; Views: 828; Downloads: 0
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15. Towards a better understanding of fine PM sources : online and offline datasets combination in a single PMFMarta Via, Jesús Yus-Díez, Francesco Canonaco, Jean-Eudes Petit, Philip Hopke, Cristina Reche, Marco Pandolfi, Matic Ivančič, Martin Rigler, Andre S. H. Prevot, 2023, original scientific article Keywords: multi-time resolution, source apportionment, submicronic particulate matter, positive matrix factorisation, PMF, multilinear engine, SoFi, ME2, organic sources, metals
Published in RUNG: 24.10.2023; Views: 944; Downloads: 6
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16. Characterizing the sources of ambient ▫$PM_10$▫ organic aerosol in urban and rural Catalonia, SpainMarten in ʼt Veld, Peeyush Khare, Yufang Hao, Cristina Reche, Noemí Perez, Andrés Alastuey, Jesús Yus-Díez, Nicolas Marchand, Andre S. H. Prevot, Xavier Querol, Kaspar Rudolf Daellenbach, 2023, original scientific article Keywords: PM10, chemical composition, organic aerosols, SOA, source apportionment
Published in RUNG: 23.10.2023; Views: 1056; Downloads: 6
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17. FOV direction and image size calibration of Fluorescence Detector using light source on UAVA. Nakazawa, Jon Paul Lundquist, 2022, published scientific conference contribution Abstract: In the Telescope Array (TA) experiment, we have been observing cosmic rays using a Fluorescence Detector (FD). More than 10 years have passed since we started this observation, and the accuracy of the observation has become more important than ever. We have developed the "Opt-copter" as a calibration device for the FDs. The Opt-copter is an unmanned aerial vehicle (UAV) equipped with a light source and can fly freely within the FD's field of view (FOV). In addition, the Opt-copter is equipped with a high-precision RTK-GPS, which enables it to accurately determine the position of the light source in flight. With this device, we can obtain detailed information on the optical characteristics of the FD. So far, we have reported on the configuration of the device and the analysis of the FOV direction. In this presentation, we will report on the new FOV analysis and image size analysis.
Keywords: Telescope Array, indirect detection, fluorescence detection, ultra-high energy, cosmic rays, light source, calibration, UAV, FOV
Published in RUNG: 04.10.2023; Views: 1054; Downloads: 7
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18. A study of analysis method for the identification of UHECR source typeF. Yoshida, Jon Paul Lundquist, 2022, published scientific conference contribution Abstract: The autocorrelation analysis using the arrival direction of Ultra High Energy Cosmic Rays (UHECRs) has been previously reported by the Telescope Array (TA) experiment. It is expected that the autocorrelation function reflects the source distribution. We simulate the expected arrival direction distribution of the cosmic rays using the catalogs of candidate sources. We take into account random deflection in the magnetic fields, with the magnitude of deflection determined by the charge and energy of the cosmic rays, coherence length and magnitude of the extragalactic magnetic field (EGMF), and by distance to source. In addition, in order to compare with the results of TA experiment, we consider the TA exposure. We compare the autocorrelation of the arrival directions corresponding to different source catalogs with the isotropic distribution. We calculate the autocorrelation function for each type of source candidates using this procedure. We will discuss the ability of this method to identify the source type of UHECRs.
Keywords: Telescope Array, indirect detection, surface detection, ground array, ultra-high energy, cosmic rays, energy spectrum, composition, anisotropy, autocorrelation, source models, magnetic fields
Published in RUNG: 04.10.2023; Views: 1008; Downloads: 8
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19. The ultra-high-energy cosmic-ray sky above 32 EeV viewed from the Pierre Auger ObservatoryJ. Biteau, Andrej Filipčič, Jon Paul Lundquist, Samo Stanič, Serguei Vorobiov, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2022, published scientific conference contribution Abstract: The region of the toe in the cosmic-ray spectrum, located at about 45 EeV by the Pierre Auger Collaboration, is of primary interest in the search for the origin of ultra-high energy cosmic rays (UHECRs). The suppression of the flux with increasing energy can be explained by the interaction of UHECRs with intergalactic photons, resulting in a shrinking of the observable universe, and/or by cut-offs in acceleration potential at the astrophysical sources, yielding a high-rigidity sample of single (or few) UHECR species around the toe. The predominance of foreground sources combined with reduced deflections could thus offer a path towards localizing ultra-high energy accelerators, through the study of UHECR arrival directions.
In this contribution, we present the results of blind and astrophysically-motivated searches for anisotropies with data collected above 32 EeV during the first phase of the Pierre Auger Observatory, i.e. prior to the AugerPrime upgrade, for an exposure of over 120,000 km^2 yr sr. We have conducted model-independent searches for overdensities at small and intermediate angular scales, correlation studies with several astrophysical structures, and cross-correlation analyses with catalogs of candidate extragalactic sources. These analyses provide the most important evidence to date for anisotropy in UHECR arrival directions around the toe as measured from a single observatory.
Keywords: Pierre Auger Observatory, indirect detection, surface detection, ground array, ultra-high energy, cosmic rays, anisotropy, overdensities, hotspot, source correlation, cross-correlation
Published in RUNG: 04.10.2023; Views: 762; Downloads: 6
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20. UHECR arrival directions in the latest data from the original Auger and TA surface detectors and nearby galaxiesA. di Matteo, Andrej Filipčič, Jon Paul Lundquist, Samo Stanič, Serguei Vorobiov, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2022, published scientific conference contribution Abstract: The distribution of ultra-high-energy cosmic-ray arrival directions appears to be nearly isotropic except for a dipole moment of order 6×(E/10 EeV) per cent. Nonetheless, at the highest energies, as the number of possible candidate sources within the propagation horizon and the magnetic deflections both shrink, smaller-scale anisotropies might be expected to emerge. On the other hand, the flux suppression reduces the statistics available for searching for such anisotropies. In this work, we consider two different lists of candidate sources: a sample of nearby starburst galaxies and the 2MRS catalog tracing stellar mass within 250 Mpc.
We combine surface-detector data collected at the Pierre Auger Observatory until 2020 and the Telescope Array until 2019, and use them to test models in which UHECRs comprise an isotropic background and a foreground originating from the candidate sources and randomly deflected by magnetic fields. The free parameters of these models are the energy threshold, the signal fraction, and the search angular scale.
We find a correlation between the arrival directions of 11.8%+5.0%−3.1% of cosmic rays detected with E≥38 EeV by Auger or with E≳49 EeV by TA and the position of nearby starburst galaxies on a 15.5∘+5.3∘−3.2∘ angular scale, with a 4.2σ post-trial significance, as well as a weaker correlation with the overall galaxy distribution.
Keywords: Pierre Auger Observatory, Telescope Array, indirect detection, surface detection, ground array, ultra-high energy, cosmic rays, anisotropy, full-sky, starburst galaxies, source correlations, dipole
Published in RUNG: 04.10.2023; Views: 822; Downloads: 4
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