1. Changes in black carbon emissions over Europe due to COVID-19 lockdownsNikolaos Evangeliou, Stephen M. Platt, Sabine Eckhardt, Cathrine Lund Myhre, Paolo Laj, L. Alados-Arboledas, John Backman, Benjamin T. Brem, Markus Fiebig, Jesús Yus-Díez, 2021, original scientific article Abstract: Abstract. Following the emergence of the severe acute respiratory syndrome coronavirus
2 (SARS-CoV-2) responsible for COVID-19 in December 2019 in Wuhan (China)
and its spread to the rest of the world, the World Health Organization
declared a global pandemic in March 2020. Without effective treatment in the
initial pandemic phase, social distancing and mandatory quarantines were
introduced as the only available preventative measure. In contrast to the
detrimental societal impacts, air quality improved in all countries in which
strict lockdowns were applied, due to lower pollutant emissions. Here we
investigate the effects of the COVID-19 lockdowns in Europe on ambient black
carbon (BC), which affects climate and damages health, using in situ
observations from 17 European stations in a Bayesian inversion framework. BC
emissions declined by 23 kt in Europe (20 % in Italy, 40 % in Germany,
34 % in Spain, 22 % in France) during lockdowns compared to the same
period in the previous 5 years, which is partially attributed to COVID-19
measures. BC temporal variation in the countries enduring the most drastic
restrictions showed the most distinct lockdown impacts. Increased particle
light absorption in the beginning of the lockdown, confirmed by assimilated
satellite and remote sensing data, suggests residential combustion was the
dominant BC source. Accordingly, in central and Eastern Europe, which
experienced lower than average temperatures, BC was elevated compared to the
previous 5 years. Nevertheless, an average decrease of 11 % was seen
for the whole of Europe compared to the start of the lockdown period, with
the highest peaks in France (42 %), Germany (21 %), UK (13 %), Spain
(11 %) and Italy (8 %). Such a decrease was not seen in the previous
years, which also confirms the impact of COVID-19 on the European emissions
of BC. Keywords: black carbon, covid-19, emissions, Europe Published in RUNG: 13.05.2024; Views: 114; Downloads: 3 Full text (11,03 MB) This document has many files! More... |
2. Applicability of benchtop multi-wavelength polar photometers to off-line measurements of the Multi-Angle Absorption Photometer (MAAP) samplesSara Valentini, Vera Bernardoni, Ezio Bolzacchini, Davide Ciniglia, Luca Ferrero, Alice Corina Forello, Dario Massabò, Marco Pandolfi, Paolo Prati, Jesús Yus-Díez, 2021, original scientific article Keywords: aerosol absorption coefficient, equivalent black carbon, MAAP, polar photometer, multi-wavelength Published in RUNG: 13.05.2024; Views: 107; Downloads: 1 Link to file This document has many files! More... |
3. Recommendations for reporting equivalent black carbon (eBC) mass concentrations based on long-term pan-European in-situ observationsMarjan Savadkoohi, Marco Pandolfi, Olivier Favez, Jean-Philippe Putaud, Konstantinos Eleftheriadis, Markus Fiebig, Philip Hopke, Paolo Laj, A. Wiedensohler, Griša Močnik, 2024, original scientific article Abstract: A reliable determination of equivalent black carbon (eBC) mass concentrations derived from filter absorption photometers (FAPs) measurements depends on the appropriate quantification of the mass absorption cross-section (MAC) for converting the absorption coefficient (babs) to eBC. This study investigates the spatial–temporal variability of the MAC obtained from simultaneous elemental carbon (EC) and babs measurements performed at 22 sites. We compared different methodologies for retrieving eBC integrating different options for calculating MAC including: locally derived, median value calculated from 22 sites, and site-specific rolling regression MAC. The eBC concentrations that underwent correction using these methods were identified as LeBC (local MAC), MeBC (median MAC), and ReBC (Rolling MAC) respectively. Pronounced differences (up to more than 50 %) were observed between eBC as directly provided by FAPs (NeBC; Nominal instrumental MAC) and ReBC due to the differences observed between the experimental and nominal MAC values. The median MAC was 7.8 ± 3.4 m2/g from 12 aethalometers at 880 nm, and 10.6 ± 4.7 m2/g from 10 MAAPs at 637 nm. The experimental MAC showed significant site and seasonal dependencies, with heterogeneous patterns between summer and winter in different regions. In addition, long-term trend analysis revealed statistically significant (s.s.) decreasing trends in EC. Interestingly, we showed that the corresponding corrected eBC trends are not independent of the way eBC is calculated due to the variability of MAC. NeBC and EC decreasing trends were consistent at sites with no significant trend in experimental MAC. Conversely, where MAC showed s.s. trend, the NeBC and EC trends were not consistent while ReBC concentration followed the same pattern as EC. These results underscore the importance of accounting for MAC variations when deriving eBC measurements from FAPs and emphasizes the necessity of incorporating EC observations to constrain the uncertainty associated with eBC. Keywords: equivalent black carbon, mass absorption cross-section, filter absorption photometers, elemental carbon, absorption, site specific MAC, rolling MAC Published in RUNG: 04.03.2024; Views: 410; Downloads: 3 Full text (2,46 MB) This document has many files! More... |
4. Investigation of multi-messenger properties of FR0 radio galaxy emitted ultra-high energy cosmic raysJon Paul Lundquist, Lukas Merten, Serguei Vorobiov, Margot Boughelilba, Albert Reimer, Paolo Da Vela, F. Tavecchio, G. Bonnoli, C. Righi, 2023, published scientific conference contribution Abstract: Low luminosity Fanaroff-Riley type 0 (FR0) radio galaxies are amongst potential contributors to the observed flux of ultra-high energy cosmic rays (UHECRs). Due to FR0s’ much higher abundance in the local universe than more powerful radio galaxies (e.g., about five times more ubiquitous at redshifts z≤0.05 than FR1s), they could provide a substantial fraction of the total UHECR energy density.
In the presented work, we determine the mass composition and energy spectrum of UHECRs emitted by FR0 sources by fitting simulation results from the CRPropa3 framework to the recently published Pierre Auger Observatory data. The resulting emission spectral characteristics (spectral indices, rigidity cutoffs) and elemental group fractions are compared to the Auger results. The FR0 simulations include the approximately isotropic distribution of FR0s extrapolated from the measured FR0 galaxy properties and various extragalactic magnetic field configurations, including random and large-scale structured fields. We predict the fluxes of secondary photons and neutrinos produced during UHECR propagation through cosmic photon backgrounds. The presented results allow for probing the properties of the FR0 radio galaxies as cosmic-ray sources using observational high-energy multi-messenger data. Keywords: ultra-high energy cosmic rays, UHECRs, Pierre Auger Observatory, UHECR propagation, UHECR interactions, UHECR energy spectrum, UHECR mass composition, UHECR sources, Fanaroff-Riley (FR) radio galaxies, FR0 galaxies Published in RUNG: 24.01.2024; Views: 569; Downloads: 8 Full text (573,28 KB) This document has many files! More... |
5. Low-luminosity jetted AGN as particle multi-messenger sourcesAnita Reimer, Margot Boughelilba, Lukas Merten, Paolo Da Vela, Jon Paul Lundquist, Serguei Vorobiov, 2023, published scientific conference contribution abstract Abstract: The detection of cosmic gamma rays, high-energy neutrinos and cosmic rays (CRs) signal the existence of environments in the Universe that allow particle acceleration to extremely high energies. These observable signatures from putative CR sources are the result of in-source acceleration of particles, their energy and time-dependent transport including interactions in an evolving environment and their escape from source, in addition to source-to-Earth propagation.
Low-luminosity AGN jets constitute the most abundant persistent jet source population in the local Universe. The dominant subset of these, Fanaroff-Riley 0 (FR0) galaxies, have recently been proposed as sources contributing to the ultra-high-energy cosmic ray (UHECR) flux observed on Earth. This presentation assesses the survival, workings and multi-messenger signatures of UHECRs in low-luminosity jet environments, with focus on FR0 galaxies. For this purpose we use our recently developed, fully time-dependent CR particle and photon propagation framework which takes into account all relevant secondary production and energy loss processes, allows for an evolving source environment and efficient treatment of transport non-linearities due to the produced particles/photons being fed back into the simulation chain.
Finally, we propagate UHE cosmic-ray nuclei and secondary cosmogenic photons and neutrinos from FR0 galaxies to Earth for several extragalactic magnetic field scenarios using the CRPropa3 framework, and confront the resulting energy spectra and composition on Earth with the current observational situation. Keywords: multi-messenger astrophysics, ultra-high-energy cosmic rays, very-high-energy gamma-rays Published in RUNG: 13.09.2023; Views: 769; Downloads: 5 Link to file This document has many files! More... |
6. The UHECR-FR0 radio galaxy connection : a multi-messenger study of energy spectra/composition emission and intergalactic magnetic field propagationJon Paul Lundquist, Lukas Merten, Serguei Vorobiov, Margot Boughelilba, Anita Reimer, Paolo Da Vela, Fabrizio Tavecchio, Giacomo Bonnoli, Chiara Righi, 2023, published scientific conference contribution Abstract: This study investigates low luminosity Fanaroff-Riley Type 0 (FR0) radio galaxies as a potentially
significant source of ultra-high energy cosmic rays (UHECRs). Due to their much higher prevalence
in the local universe compared to more powerful radio galaxies (about five times more than
FR-1s), FR0s may provide a substantial fraction of the total UHECR energy density. To determine
the nucleon composition and energy spectrum of UHECRs emitted by FR0 sources, simulation
results from CRPropa3 are fit to Pierre Auger Observatory data. The resulting emission spectral
indices, rigidity cutoffs, and nucleon fractions are compared to recent Auger results. The FR0 simulations
include the approximately isotropic distribution of FR0 galaxies and various intergalactic
magnetic field configurations (including random and structured fields) and predict the fluxes of
secondary photons and neutrinos produced during UHECR propagation through cosmic photon
backgrounds. This comprehensive simulation allows for investigating the properties of the FR0
sources using observational multi-messenger data. Keywords: ultra-high energy cosmic rays, UHECR propagation, CRPropa, active galactic nuclei, jetted AGN, FR0 radio galaxies, Pierre Auger Observatory, UHECR energy spectrum Published in RUNG: 24.08.2023; Views: 775; Downloads: 4 Full text (1,12 MB) This document has many files! More... |
7. CR-ENTREES - Cosmic-Ray ENergy TRansport in timE-Evolving astrophysical SettingsAnita Reimer, Lukas Merten, Margot Boughelilba, Paolo Da Vela, Serguei Vorobiov, Jon Paul Lundquist, 2023, published scientific conference contribution Abstract: In order to understand observable signatures from putative cosmic-ray (CR) sources in-source
acceleration of particles, their energy and time-dependent transport including interactions in an
evolving environment and their escape from source have to be considered, in addition to sourceto-
Earth propagation.
We present the code CR-ENTREES (Cosmic-Ray ENergy TRansport in timE-Evolving astrophysical
Settings) that evolves the coupled time- and energy-dependent kinetic equations for cosmicray
nucleons, pions, muons, electrons, positrons, photons and neutrinos in a one-zone setup of
(possibly) non-constant size, with user-defined particle and photon injection laws. All relevant
interactions, particle/photon escape and adiabatic losses are considered in a radiation-dominated,
magnetized astrophysical environment that is itself evolving in time. Particle and photon interactions
are pre-calculated using event generators assuring an accurate interactions and secondary
particle production description. We use the matrix multiplication method for fast radiation and
particle energy transport which allows also an efficient treatment of transport non-linearities due
to the produced particles/photons being fed back into the simulation chain.
Examples for the temporal evolution of the non-thermal emission from AGN jet-like systems with
focus on proton-initiated pair cascades inside an expanding versus straight jet emission region, are
further presented. Keywords: cosmic rays, CR energy transport, CR interactions Published in RUNG: 24.08.2023; Views: 785; Downloads: 3 Full text (442,19 KB) This document has many files! More... |
8. Efficient modeling of heavy cosmic rays propagation in evolving astrophysical environmentsLukas Merten, Paolo Da Vela, Anita Reimer, Jon Paul Lundquist, Margot Boughelilba, Serguei Vorobiov, J. Becker Tjus, 2023, published scientific conference contribution Abstract: We present a new energy transport code that models the time dependent and non-linear evolution
of spectra of cosmic-ray nuclei, their secondaries, and photon target fields. The software can inject
an arbitrary chemical composition including heavy elements up to iron nuclei. Energy losses and
secondary production due to interactions of cosmic ray nuclei, secondary mesons, leptons, or
gamma-rays with a target photon field are available for all relevant processes, e.g., photo-meson
production, photo disintegration, synchrotron radiation, Inverse Compton scattering, and more.
The resulting x-ray fluxes can be fed back into the simulation chain to correct the initial photon
targets, resulting in a non-linear treatment of the energy transport. The modular structure of the
code facilitates simple extension of interaction or target field models.
We will show how the software can be used to improve predictions of observables in various
astrophysical sources such as jetted active galactic nuclei (AGN). Since the software can model
the propagation of heavy ultrahigh-energy cosmic rays inside the source it can precisely predict
the chemical composition at the source. This will also refine predictions of neutrino emissions
–– they strongly depend on the chemical composition. This helps in the future to optimize the
selection and analyses of data from the IceCube neutrino observatory with the aim to enhance the
sensitivity of IceCube and reduce the number of trial factors. Keywords: cosmic rays, low-luminosity jetted AGNCR energy transport, CR interactions Published in RUNG: 24.08.2023; Views: 761; Downloads: 4 Full text (1,12 MB) This document has many files! More... |
9. THERMOCHEMICAL CONVERSION OF MARINE LITTER INTO FUELS AND CHEMICALSGian Claudio Paolo Faussone, 2023, doctoral dissertation Abstract: Plastic waste is steadily polluting oceans and environments. Even when collected, it is still predominantly dumped or incinerated for energy recovery at the cost of CO2. However, no simple solution exists to deal with marine litter (ML). Overcoming limitations in collection, and in the environmentally, technically and economically acceptable use of the collected material, is of paramount importance. Chemical recycling can contribute to the transition towards a circular economy but the high variety and contamination of real waste remains the biggest challenge. In my research more than 100 kg of actual benthic ML from the North Adriatic Sea, including polyolefins packaging and polyamides fishing nets, were successfully processed “as-is” without pretreatment and converted into standardized marine gas oil (MGO) compliant with the ISO8217 via the pyrolysis and the distillation process; with 8 potential harmful emissions linked to the pyrolysis process monitored and curbed to safe levels. Approximately 45 wt% yield of raw pyrolysis oil (RPO) was obtained of which 50% (v/v) being MGO. RPO and its distillates were chemically characterized via GC-MS. For all samples, more than 30% of the detected compounds were identified. 2,4-dimethyl-1-heptene, a marker of PP pyrolysis, is the most represented peak in the chemical signature of all the marine litter samples, and it differentiates commercial and pyrolysis marine gasoil. Besides, I studied the detailed composition and the steam cracking performance of distilled pyrolysis oil fractions in the naphtha-range of ML and mixed municipal plastic waste (MPW) considered unsuitable for mechanical recycling. Advanced analytical techniques including comprehensive two-dimensional gas chromatography (GC × GC) coupled with various detectors and inductively coupled plasma – mass spectrometry (ICP-MS) was applied to characterize the feedstocks and to understand how their properties affect the steam cracking performance. Both waste-derived naphtha fractions were rich in olefins and aromatics (~70% in MPW naphtha and ~51% in ML naphtha) next to traces of nitrogen, oxygen, chlorine and metals. ICP-MS analyses showed that sodium, potassium, silicon and iron were the most crucial metals that should be removed in further upgrading steps. Steam cracking of the waste-derived naphtha fractions resulted in lower light olefin yields compared to fossil naphtha used as benchmark, due to secondary reactions of aromatics and olefins. Coke formation of ML naphtha was slightly increased compared to fossil naphtha (~50%), while that of MPW naphtha was more than ~180% higher. It was concluded that mild upgrading of the waste-derived naphtha fractions or dilution with fossil feedstocks is sufficient to provide feedstocks suitable for industrial steam cracking. Waste plastics oil (WPO) obtained from a relatively large-scale batch rotary kiln pyrolysis reactor was collected and stored for 60 months in dark at 10 °C, periodically thoroughly characterized and finally tested as the drop-in fuel in internal combustion engine. It was evaluated by investigation of combustion process and emission formation phenomena under a wide range of operating parameters. The results were compared with those obtained with diesel fuel at the same injection and gas path parameters to provide a comprehensive basis for further development of control strategies. Finally, the solid residue from the pyrolysis process was evaluated for material recovery or safe disposal, thus closing the mass balance of the whole process. Due to the great contamination of the original feedstock, stabilization of solid residue is required to attain not hazardous waste criteria, but once stabilized with Portland concrete, it could even be employed as construction material, therefore transforming a problem into an opportunity. Keywords: marine litter, marine fuel, pyrolysis, circular economy, environmental impact, chemical recycling, steam-cracking, pyrolysis char Published in RUNG: 12.05.2023; Views: 1306; Downloads: 20 Full text (14,33 MB) |
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