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JATAC/CAVA-AW Aeolus Cal/Val airborne campaign dataset
Jesus Yus-Diez, Griša Močnik, Luka Drinovec, Marija Bervida Mačak, Blaž Žibert, Uroš Jagodič, Matevž Lenarčič, complete scientific database of research data

Abstract: Light aircraft (WT10 - experimental) with position and windspeed variables provided by onboard GPS, as well as additional meteorological sensors. The aircraft was mounted with a: a sunshine pyranometer type SPN1 (Delta-T Devices Ltd), a polar integrating nephelometer AURORA 4000 (Ecotech Pty Ltd), and had a dual sampling line aircraft for measurements at the fine and coarse fraction of the absorption by two Continuous Light Absorption Photometer (CLAPS, by Haze Instruments d.o.o.) and the particle size distribution by two optical particle counters (OPC, model 11D, GRIMM Technologies). The pyranometer provides measurements of the global, direct and diffuse irradiance for a radiation spectrum range between 400 and 2700nm with a 1s time resolution. The polar integrating nephelometer measures the scattering coefficients of particles at three wavelengths (450, 525 and 635 nm) and multiple angles (two selected for the campaign: 0, 90deg) with a 5s time resolution. The CLAP photometers measure the absorption coefficient by aerosol particles at three wavelengths (467, 529 and 653 nm) with a 1s time resolution. The OPC measurements provide the number and mass concentration of aerosol particles for 31 bins in the size range between 0.253 and 35.15 micrometers with a 6s time resolution. The 2021 and 2022 campaigns are found at:
Keywords: Aeolus satellite, Saharan dust, aerosol, calibration, validation
Published in RUNG: 27.09.2023; Views: 49; Downloads: 0
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Abstract: The present invention belongs to the field of devices and methods for measurement of particle concentration, more precisely to the field of devices and methods for quantification of particles based ontheir physical characteristics, especially with the use of optical means. The invention relates to a method for determination of ambient mineral dust concentration based on optical absorption of particles concentrated by a virtual impactor as well as a device performing the said method. The method comprises the following steps: sampling air samples with particle size smaller than 1 mum (PM1) andsampling air samples with particle size up to 10 mum; concentrating the samples with particle sizes up to 10 mum with a virtual impactor; measuring optical absorption of collected samples at least onewavelength from UV to IR spectre, preferably from 370 to 950 nm, most preferably at 370 nm; subtracting the absorption of the samples with particle size smaller than 1 mum from the absorption of thesample concentrated by the virtual impactor.
Keywords: dust, black carbon, aerosol
Published in RUNG: 07.03.2023; Views: 560; Downloads: 0
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Investigation of Aerosol Types and Vertical Distributions Using Polarization Raman Lidar over Vipava Valley
Longlong Wang, Marija Bervida Mačak, Samo Stanič, Klemen Bergant, Asta Gregorič, Luka Drinovec, Zhenping Yin, Yang Yi, Detlef Müller, Xuan Wang, 2022, original scientific article

Abstract: Aerosol direct radiative forcing is strongly dependent on aerosol distributions and aerosol types. A detailed understanding of such information is still missing at the Alpine region, which currently undergoes amplified climate warming. Our goal was to study the vertical variability of aerosol types within and above the Vipava valley (45.87◦ N, 13.90◦ E, 125 m a.s.l.) to reveal the vertical impact of each particular aerosol type on this region, a representative complex terrain in the Alpine region which often suffers from air pollution in the wintertime. This investigation was performed using the entire dataset of a dual-wavelength polarization Raman lidar system, which covers 33 nights from September to December 2017. The lidar provides measurements from midnight to early morning (typically from 00:00 to 06:00 CET) to provide aerosol-type dependent properties, which include particle linear depolarization ratio, lidar ratio at 355 nm and the aerosol backscatter Ångström exponent between 355 nm and 1064 nm. These aerosol properties were compared with similar studies, and the aerosol types were identified by the measured aerosol optical properties. Primary anthropogenic aerosols within the valley are mainly emitted from two sources: individual domestic heating systems, which mostly use biomass fuel, and traffic emissions. Natural aerosols, such as mineral dust and sea salt, are mostly transported over large distances. A mixture of two or more aerosol types was generally found. The aerosol characterization and statistical properties of vertical aerosol distributions were performed up to 3 km.
Keywords: valley air pollution, aerosol vertical distributions, lidar remote sensing, aerosol identification
Published in RUNG: 21.07.2022; Views: 875; Downloads: 23
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A dual-wavelength photothermal aerosol absorption monitor : design, calibration and performance
Luka Drinovec, Uroš Jagodič, Luka Pirker, Miha Škarabot, Mario Kurtjak, Kristijan Vidović, Luca Ferrero, Bradley Visser, Jannis Röhrbein, Ernest Weingartner, Daniel M. Kalbermatter, Konstantina Vasilatou, Griša Močnik, 2022, original scientific article

Abstract: There exists a lack of aerosol absorption measurement techniques with low uncertainties and without artefacts. We have developed the two-wavelength Photothermal Aerosol Absorption Monitor (PTAAM-2λ), which measures the aerosol absorption coefficient at 532 and 1064 nm. Here we describe its design, calibration and mode of operation and evaluate its applicability, limits and uncertainties. The 532 nm channel was calibrated with ∼ 1 µmol mol−1 NO2, whereas the 1064 nm channel was calibrated using measured size distribution spectra of nigrosin particles and a Mie calculation. Since the aerosolized nigrosin used for calibration was dry, we determined the imaginary part of the refractive index of nigrosin from the absorbance measurements on solid thin film samples. The obtained refractive index differed considerably from the one determined using aqueous nigrosin solution. PTAAM-2λ has no scattering artefact and features very low uncertainties: 4 % and 6 % for the absorption coefficient at 532 and 1064 nm, respectively, and 9 % for the absorption Ångström exponent. The artefact-free nature of the measurement method allowed us to investigate the artefacts of filter photometers. Both the Aethalometer AE33 and CLAP suffer from cross-sensitivity to scattering – this scattering artefact is most pronounced for particles smaller than 70 nm. We observed a strong dependence of the filter multiple scattering parameter on the particle size in the 100–500 nm range. The results from the winter ambient campaign in Ljubljana showed similar multiple scattering parameter values for ambient aerosols and laboratory experiments. The spectral dependence of this parameter resulted in AE33 reporting the absorption Ångström exponent for different soot samples with values biased 0.23–0.35 higher than the PTAAM-2λ measurement. Photothermal interferometry is a promising method for reference aerosol absorption measurements.
Keywords: aerosol absorption, calibration, black carbon
Published in RUNG: 28.06.2022; Views: 733; Downloads: 24
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The impact of temperature inversions on black carbon and particle mass concentrations in a mountainous area
Kristina Glojek, Griša Močnik, Honey Dawn C. Alas, Andrea Cuesta-Mosquera, Luka Drinovec, Asta Gregorič, Matej Ogrin, Kay Weinhold, Irena Ježek, Martin Rigler, Maja Remškar, Miha Markelj, 2022, original scientific article

Abstract: Residential wood combustion is a widespread practice in Europe with a serious impact on air quality, especially in mountainous areas. While there is a significant number of studies conducted in deep urbanized valleys and basins, little is known about the air pollution processes in rural shallow hollows, where around 30 % of the people in mountainous areas across Europe live. We aim to determine the influence of ground temperature inversions on wood combustion aerosol pollution in hilly, rural areas. The study uses Retje karst hollow (Loški Potok, Slovenia) as a representative site for mountainous and hilly rural areas in central and south-eastern Europe with residential wood combustion. Sampling with a mobile monitoring platform along the hollow was performed in December 2017 and January 2018. The backpack mobile monitoring platform was used for the determination of equivalent black carbon (eBC) and particulate matter (PM) mass concentrations along the hollow. To ensure high quality of mobile measurement data, intercomparisons of mobile instruments with reference instruments were performed at two air quality stations during every run. Our study showed that aerosol pollution events in the relief depression were associated with high local emission intensities originating almost entirely from residential wood burning and shallow temperature inversions (58 m on average). The eBC and PM mass concentrations showed stronger associations with the potential temperature gradient (R2=0.8) than with any other meteorological parameters taken into account (ambient temperature, relative humidity, wind speed, wind direction, and precipitation). The strong association between the potential temperature gradient and pollutant concentrations suggests that even a small number of emission sources (total 243 households in the studied hollow) in similar hilly and mountainous rural areas with frequent temperature inversions can significantly increase the levels of eBC and PM and deteriorate local air quality. During temperature inversions the measured mean eBC and PM2.5 mass concentrations in the whole hollow were as high as 4.5±2.6 and 48.0 ± 27.7 µg m−3, respectively, which is comparable to larger European urban centres.
Keywords: air pollution, black carbon, sources, temperature inversion, mountainous area
Published in RUNG: 03.05.2022; Views: 889; Downloads: 0
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Comparing black-carbon- and aerosol-absorption-measuring instruments – a new system using lab-generated soot coated with controlled amounts of secondary organic matter
Daniel M. Kalbermatter, Griša Močnik, Luka Drinovec, Bradley Visser, Jannis Röhrbein, Matthias Oscity, Ernest Weingartner, Antti-Pekka Hyvärinen, Konstantina Vasilatou, 2022, original scientific article

Abstract: We report on an inter-comparison of black-carbon- and aerosol-absorption-measuring instruments with laboratory-generated soot particles coated with controlled amounts of secondary organic matter (SOM). The aerosol generation setup consisted of a miniCAST 5201 Type BC burner for the generation of soot particles and a new automated oxidation flow reactor based on the micro smog chamber (MSC) for the generation of SOM from the ozonolysis of α-pinene. A series of test aerosols was generated with elemental to total carbon (EC  TC) mass fraction ranging from about 90 % down to 10 % and single-scattering albedo (SSA at 637 nm) from almost 0 to about 0.7. A dual-spot Aethalometer AE33, a photoacoustic extinctiometer (PAX, 870 nm), a multi-angle absorption photometer (MAAP), a prototype photoacoustic instrument, and two prototype photo-thermal interferometers (PTAAM-2λ and MSPTI) were exposed to the test aerosols in parallel. Significant deviations in the response of the instruments were observed depending on the amount of secondary organic coating. We believe that the setup and methodology described in this study can easily be standardised and provide a straightforward and reproducible procedure for the inter-comparison and characterisation of both filter-based and in situ black-carbon-measuring (BC-measuring) instruments based on realistic test aerosols.
Keywords: black carbon, aerosol absorption, secondary organic aerosol, coating
Published in RUNG: 01.02.2022; Views: 1141; Downloads: 43
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