UHECR interactions with earth's magnetic field and the earth's atmosphere, EAC simulations, atmospheric monitoring through the development of a Doppler interferometer

Στο πρώτο κεφάλαιο αρχικά γίνεται μια εισαγωγή στο πεδίο των κοσμικών ακτίνων και την πρότερη - υπάρχουσα κατάσταση. Εισάγεται το θέμα της παρατήρησης κοσμικών ακτίνων με την υβριδική τεχνική. Γίνεται ανάλυση της τεχνικής ατμοσφαιρικού φθορισμού. Στο δεύτερο κεφάλαιο δίνονται θέματα προσομοιώσεων κοσμικών ακτίνων σχετικά με το θέμα της ατμοσφαιρικής επισκόπησης για πειράματα για φωτόνια σαν πρωταρχικά σωματίδια σε υπέρυψηλές αλλά και υψηλές ενέργειες σχετικά με τα πειράματα που μας απασχολούν (Pierre Auger, EUSO, GEMEUSO, CTA). Γίνεται εμβάθυνση στο θέμα της ατμοσφαιρικής επισκόπησης για πειράματα ΕΑΚ με συστήματα LIDAR που είναι απαραίτητα για την τεχνική του ατμοσφαιρικού φθορισμού. Στο τρίτο κεφάλαιο δίνεται μια θεωρητική προσέγγιση για την προτεινόμενη σχεδίαση ενός προτύπου HSRL για πειράματα ΕΑΚ. Αρχικά δίνονται οι ανάγκες των πειραμάτων για ατμοσφαιρική επισκόπηση και στη συνέχεια αναλύονται οι τεχνικές που χρησιμοποιούνται. Ακολούθως αναπτύσσεται η σχεδίαση αλλά και όλες οι απαραίτητες παράμετροι. Η ανάλυση των πειραμάτων αλλά και οι αλγόριθμοι που χρησιμοποιούνται σε διάφορα μέρη του συστήματος και των διατάξεων αναλύονται στο τέταρτο κεφάλαιο. Αρχικά δίνονται οι μέθοδοι που χρησιμοποιούνται για την εξαγωγή συμπερασμάτων από CCD σε συμβολόμετρα και η μαθηματική προσέγγιση τους. Ακόμη αναλύεται το θέμα του αλγόριθμου για την εξαγωγή των μετρήσιμων ποσοτήτων από το σχεδιαζόμενο HSRL. Το πέμπτο κεφάλαιο περιέχει το πειραματικό μέρος της διατριβής. Περιέχει μετρήσεις και αποτελέσματα από πειράματα φραγμάτων περίθλασης αλλά και συμβολομετρίας. Οι φασματοσκοπικές μετρήσεις περίθλασης έγιναν στα πλαίσια της εξέτασης του υποβάθρου του νυκτερινού ουρανού αλλά και του φάσματος φθορισμού του αέρα. Οι συμβολομετρικές μετρήσεις που είναι και το κύριο αντικείμενο της εργασίας σχετίζονται με θέματα χαρακτηρισμού δεσμών Laser, συμβολομέτρων Fabry-Perot, αλλά και με την ανάπτυξη της σχεδίασης του HSRL που προτείνεται. Στο έκτο κεφάλαιο εισάγεται το θέμα της τροφοδοσίας των ανιχνευτών Cherenkov ύδατος από φωτοβολταϊκα για πειράματα ΕΑΚ. Γίνεται αρχικά μια εισαγωγή στο θέμα των φωτοβολταικών συστημάτων και στη συνέχεια αναλύεται η διαστασιολόγηση ενός τέτοιου συστήματος και τα υποσυστήματα. Ακολούθως γίνεται μια προσομοίωση ενός αντιστοίχου συστήματος σε περιβάλλον Matlab/Simulink. Ακόμη το θέμα των καρτών επικοινωνίας με τον ανιχνευτή αναλύεται από την πλευρά των περιβαλλοντικών καταπονήσεων

Annual Variability of Black Carbon Concentrations Originating from Biomass and Fossil Fuel Combustion for the Suburban Aerosol in Athens, Greece

The objective of this work was to assess the yearly contribution of fossil fuel combustion (BCff) and wood burning (BCwb) to equivalent black carbon (eBC) concentrations, in Athens, Greece. Measurements were conducted at a suburban site from March 2013 to February 2014 and included absorption coefficients at seven wavelengths and PM2.5 chemical composition data for key biomass burning markers, i.e., levoglucosan, potassium (K) and elemental and organic carbon (EC, OC). A well-documented methodology of corrections for aethalometer attenuation coefficients was applied with a resulting annual dataset of derived absorption coefficients for the suburban Athens’ atmospheric aerosol. The Aethalometer model was applied for the source apportionment of eBC. An optimum Ångström exponent for fossil fuel (αff) was found, based on the combined use of the model with levoglucosan data. The measured eBC concentrations were equal to 2.4 ± 1.0 μg m−3 and 1.6 ± 0.6 μg m−3, during the cold and the warm period respectively. The contribution from wood burning was significantly higher during the cold period (21 ± 11%, versus 6 ± 7% in the warm period). BCff displayed a clear diurnal pattern with a morning peak between 8 and 10 a.m. (during morning rush hour) and a second peak during the evening and night hours, due to the shallowing of the mixing layer. Regression analysis between BCwb concentrations and biomass burning markers (levoglucosan, K and OC/EC ratio) supported the validity of the results

PM_2.5 Source Apportionment and Implications for Particle Hygroscopicity at an Urban Background Site in Athens, Greece

Aerosol hygroscopicity is a key aerosol property, influencing a number of other physical properties, and the impacts of PM pollution on the environment, climate change, and health. The present work aims to provide insight into the contribution of major PM sources to aerosol hygroscopicity, focusing on an urban background site, with a significant impact from both primary and secondary sources. The EPA PMF 5.0 model was applied to PM2.5 chemical composition and hygroscopicity data collected from August 2016 to July 2017 in Athens, Greece. Source apportionment analysis resulted in six major sources, including four anthropogenic sources (vehicular exhaust and non-exhaust, heavy oil combustion, and a mixed source of secondary aerosol formation and biomass burning) and two natural sources (mineral dust and aged sea salt). The mixed source was found to be the main contributor to PM2.5 levels (44%), followed by heavy oil combustion (26%) and vehicular traffic exhaust and non-exhaust emissions (15%). The aerosol hygroscopic growth factor (GF) was found to be mainly associated with the mixed source (by 36%) and heavy oil combustion (by 24%) and, to a lesser extent, with vehicle exhaust (by 19%), aged sea salt (by 14%), and vehicle non-exhaust (by 6%)

Indoor and outdoor air quality in street corner kiosks in a large metropolitan area

Poor air quality in workplaces constitutes a great concern on human health as a good fraction of our time is spent at work. In Greece, very unique workplaces are the street corner kiosks, which are freestanding boxes placed on sidewalks next to city streets and vehicular traffic, where one can find many consumer goods. As such, its employees are exposed to both outdoor and indoor air pollutants. Very few studies have examined the occupational exposure of kiosk workers to air pollutants, and thus the magnitude of this unique indoor and outdoor exposure remains unknown. The objective of this study is to investigate and compare the levels of indoor and outdoor particulate matter (PM10 and PM2.5), ultrafine particles (UFPs) and black carbon (BC) in different kiosks located in Athens, Greece, in urban-traffic and urban-background environments. Continuous measurements of the above-mentioned pollutants were carried out on a 24-h basis over 7 consecutive days at three kiosks from September to October 2019. Indoor PM10 concentrations in the urban kiosk ranged from 19.0 to 44.0 μg/m3, PM2.5 values ranged from 14.0 to 33.0 μg/m3, whereas BC concentrations ranged from 1.2 to 7.0 μg/m3 and UFPs from almost 9.5 to 47.0 × 103 pt/cm3. Outdoor PM10 and PM2.5 measurements ranged from 29.0 to 59.0 μg/m3 and from 22.0 to 39.0 μg/m3, respectively. BC outdoor concentrations ranged from 1.1 to 2.2 μg/m3. The mean hazard quotient (HQ) for PM10 (4.9) and PM2.5 (4.7) among all participants was >1. The health risk of exposure to PM10 and PM2.5 was found to be at moderate hazard levels, although in some cases we observed HQ values higher than 10 due to high PM10 and PM2.5 concentrations in the kiosks. Overall our study indicates that people working at kiosks can be exposed to very high concentrations on particulate pollution depending on a number of factors including the traffic that strongly depends on location and the time of the day.Atmospheric Remote Sensin

Linking indoor particulate matter and black carbon with sick building syndrome symptoms in a public office building

Poor indoor air quality is an important issue for public and occupational health worldwide. Location, air-tightness of the building, ventilation rate and resident activities play an important role on the concentration of indoor pollutants and subsequently on their effects on human health. While indoor air pollution in working environments has been widely studied, the association between specific pollutants and Sick Building Syndrome (SBS) symptoms is still not clear. The objective of this study is to explore the association between PM2.5 and BC with SBS symptoms reported by employees working in a public building in the center of Athens, Greece. Continuous indoor air quality measurements were carried out from March until May 2016 (24 h, 7 days per week), including days during a Saharan dust event in March 2016. The measurements took place in four different types of spaces, including an office, a printer room and two archiving rooms, representing both high and low exposure environments. Indoor PM2.5 and BC concentrations in the office ranged from 5.9 to 14.3 μg/m3 and 1.1–1.9 μg/m3, respectively, whereas outdoor PM2.5 and BC concentrations were in the range of 6.5–21.7 μg/m3 and 1.4–2.6 μg/m3, respectively. We observed diurnal variations in indoor/outdoor ratios of PM2.5 and BC in most rooms that were >1 during working hours, that subsequently fell to below unity after working hours. Data collected via a questionnaire to 73 employees showed that the most commonly reported SBS symptoms were irritation of the eyes, a stuffy or runny nose, headache and drowsiness. Female employees were more likely to report SBS symptoms than male employees, especially nonspecific symptoms, including “unusual tiredness or fatigue” and “feeling depressed”.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Atmospheric Remote Sensin

Corrigendum to “Linking indoor particulate matter and black carbon with sick building syndrome symptoms in a public office building” [Atmos. Pollut. Res. 13 (2022) 101292] (Atmospheric Pollution Research (2022) 13(1), (S1309104221003548), (10.1016/j.apr.2021.101292))

The authors would like to replace <14. W03.31.000 > with <N075-15-2021-574> in the acknowledgement. We apologise for any inconvenience caused.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Atmospheric Remote Sensin

A global analysis of climate-relevant aerosol properties retrieved from the network of Global Atmosphere Watch (GAW) near-surface observatories

Aerosol particles are essential constituents of the Earth's atmosphere, impacting the earth radiation balance directly by scattering and absorbing solar radiation, and indirectly by acting as cloud condensation nuclei. In contrast to most greenhouse gases, aerosol particles have short atmospheric residence times, resulting in a highly heterogeneous distribution in space and time. There is a clear need to document this variability at regional scale through observations involving, in particular, the in situ near-surface segment of the atmospheric observation system. This paper will provide the widest effort so far to document variability of climate-relevant in situ aerosol properties (namely wavelength dependent particle light scattering and absorption coefficients, particle number concentration and particle number size distribution) from all sites connected to the Global Atmosphere Watch network. High-quality data from almost 90 stations worldwide have been collected and controlled for quality and are reported for a reference year in 2017, providing a very extended and robust view of the variability of these variables worldwide. The range of variability observed worldwide for light scattering and absorption coefficients, single-scattering albedo, and particle number concentration are presented together with preliminary information on their long-term trends and comparison with model simulation for the different stations. The scope of the present paper is also to provide the necessary suite of information, including data provision procedures, quality control and analysis, data policy, and usage of the ground-based aerosol measurement network. It delivers to users of the World Data Centre on Aerosol, the required confidence in data products in the form of a fully characterized value chain, including uncertainty estimation and requirements for contributing to the global climate monitoring system.Peer reviewe

A European aerosol phenomenology – 6: scattering properties of atmospheric aerosol particles from 28 ACTRIS sites

International audienceThis paper presents the light-scattering properties of atmospheric aerosol particles measured over the past decade at 28 ACTRIS observatories, which are located mainly in Europe. The data include particle light scattering (σsp) and hemispheric backscattering (σbsp) coefficients, scattering Ångström exponent (SAE), backscatter fraction (BF) and asymmetry parameter (g). An increasing gradient of σsp is observed when moving from remote environments (arctic/mountain) to regional and to urban environments. At a regional level in Europe, σsp also increases when moving from Nordic and Baltic countries and from western Europe to central/eastern Europe, whereas no clear spatial gradient is observed for other station environments. The SAE does not show a clear gradient as a function of the placement of the station. However, a west-to-east-increasing gradient is observed for both regional and mountain placements, suggesting a lower fraction of fine-mode particle in western/south-western Europe compared to central and eastern Europe, where the fine-mode particles dominate the scattering. The g does not show any clear gradient by station placement or geographical location reflecting the complex relationship of this parameter with the physical properties of the aerosol particles. Both the station placement and the geographical location are important factors affecting the intra-annual variability. At mountain sites, higher σsp and SAE values are measured in the summer due to the enhanced boundary layer influence and/or new particle-formation episodes. Conversely, the lower horizontal and vertical dispersion during winter leads to higher σsp values at all low-altitude sites in central and eastern Europe compared to summer. These sites also show SAE maxima in the summer (with corresponding g minima). At all sites, both SAE and g show a strong variation with aerosol particle loading. The lowest values of g are always observed together with low σsp values, indicating a larger contribution from particles in the smaller accumulation mode. During periods of high σsp values, the variation of g is less pronounced, whereas the SAE increases or decreases, suggesting changes mostly in the coarse aerosol particle mode rather than in the fine mode. Statistically significant decreasing trends of σsp are observed at 5 out of the 13 stations included in the trend analyses. The total reductions of σsp are consistent with those reported for PM2.5 and PM10 mass concentrations over similar periods across Europe

A European aerosol phenomenology-6: Scattering properties of atmospheric aerosol particles from 28 ACTRIS sites [Discussion paper]

This investigation presents the variability of near-surface in-situ aerosol particle light scattering measurements obtained over the past decade at 28 measuring atmospheric observatories which are part of the ACTRIS Research Infrastructure and most of them belong to the GAW network. This manuscript provides a comprehensive picture of the spatial and temporal variability of aerosol particles optical properties in Europe.This project has received funding from the European Union’s Horizon 2020 research and 11 innovation programme under grant agreement No 654109, ACTRIS (project No. 262254), ACTRIS12 PPP (project No 739530).MAD station is co-financed by the PROACLIM ( CGL2014-52877-R) project. SMR station acknowledges BACCHUS (project No. 603445), CRAICC (project No. 26060) and Academy of Finland (project No. 3073314). UGR station is co-financed by the Spanish Ministry of Economy and Competitiveness through project CGL2016-81092-R. Measurements at Montseny and Montsec stations were supported by the MINECO (Spanish Ministry of Economy and Competitiveness) and FEDER funds under the PRISMA project (CGL2012-39623-C02/00), by the MAGRAMA (Spanish Ministry of Agriculture, Food and Environment) and by the Generalitat de Catalunya (AGAUR 2014 SGR33 and the DGQA). Measurements at Izaña were supported by AEROATLAN project (CGL2015-17 66229-P), co-funded by the Ministry of Economy and Competitiveness of Spain and the European Regional Development Fund. Station Košetice is supported by Ministry of Education, Youth and Sports of the Czech Republic within project for support of national research infrastructure ACTRIS – participation of the Czech Republic (ACTRIS-CZ – LM2015037). Measurements at Puy de Dôme were partly supported by CNRS-INSU, University Clermont- Auvergne, OPGC and the french CLAP program. PAL station acknowledges KONE Foundation, Academy of Finland (project No. 269095 and No. 296302). CHC station received support from Institut de Recherche pour le Développement (IRD) under both Jeune Equipe program attributed to LFA and support to ACTRIS-FR program. CHC received grants from Labex OSUG@2020 (Investissements d’avenir – ANR10 LABX56). Marco Pandolfi is funded by a Ramón y Cajal Fellowship (RYC-2013-14036) awarded by the Spanish Ministry of Economy and Competitiveness