11. |
12. Airborne in-situ measurements during JATAC/CAVA-AW 2021/2022 campaigns : first climate-relevant resultsJesús Yus-Díez, Marija Bervida, Luka Drinovec, Blaž Žibert, Matevž Lenarčič, Griša Močnik, 2023, published scientific conference contribution abstract Abstract: The JATAC campaign in September 2021 and September 2022 on and above Cape Verde Islands have resulted in a large dataset of in-situ and remote measurements. In addition to the calibration/validation of the ESA’s Aeolus ALADIN during the campaign, the campaign also featured secondary scientific objectives related to climate change. The atmosphere above the Atlantic Ocean off the coast of West Africa is ideal for the study of the Saharan Aerosol layer (SAL), the long-range transport of dust, and the regional influence of SAL aerosols on the climate.
We have instrumented a light aircraft (Advantic WT-10) with instrumentation for the in-situ aerosol characterization. Ten flights were conducted over the Atlantic Ocean up to over 3000 m above sea level during two intense dust transport events. PollyXT, and EvE lidars were deployed at the Ocean Science Center, measuring the vertical optical properties of aerosols and were also used to plan the flights.
The particle light absorption coefficient was determined at three different wavelengths with Continuous Light Absorption Photometers (CLAP). They were calibrated with the dual wavelength photo-thermal interferometric measurement of the aerosol light-absorption coefficient in the laboratory. The particle size distributions above 0.3 µm diameter were measured with two Grimm 11-D Optical Particle Size Spectrometers (OPSS). These measurements were conducted separately for the fine aerosol fraction and the enriched coarse fraction using an isokinetic inlet and a pseudo-virtual impactor, respectively.
The aerosol light scattering and backscattering coefficients were measured with an Ecotech Aurora 4000 nephelometer. The instrument used a separate isokinetic inlet and was calibrated prior to and its calibration validated after the campaign with CO2. We have measured the total and diffuse solar irradiance with a DeltaT SPN1 pyranometer. CO2 concentration, temperature, aircraft GPS position altitude, air and ground speed were also measured.
The in-situ single-scattering albedo Angstrom exponent and the lidar depolarization ratio will be compared as two independent parameters indicating the presence of Saharan dust. We will show differences between homogeneous Saharan dust layer in space (horizontally and vertically) and time and events featuring strong horizontal gradients in aerosol composition and concentration, and layering in the vertical direction. These layers often less than 100 m thick, separated by layers of air with no dust.
Complex mixtures of aerosols in the outflow of Saharan dust over the Atlantic Ocean in the tropics will be characterized. We will show the in-situ atmospheric heating/cooling rate and provide insight into the regional and local effects of this heating of the dust layers. These measurements will support of the research on evolution, dynamics, and predictability of tropical weather systems and provide input into and verification of the climate models.
Keywords: mineral dust, climate change, heating rate, black carbon, Aeolus satellite, airborne measurements
Published in RUNG: 21.12.2023; Views: 550; Downloads: 4
 Full text (292,05 KB)
This document has many files! More... |
13. Anthropic settlementsʹ impact on the light-absorbing aerosol concentrations and heating rate in the arcticNiccolò Losi, Piotr Markuszewski, Martin Rigler, Asta Gregorič, Griša Močnik, Violetta Drozdowska, Przemek Makuch, Tymon Zielinski, Paulina Pakszys, Małgorzata Kitowska, 2023, original scientific article Abstract: Light-absorbing aerosols (LAA) impact the atmosphere by heating it. Their effect in the Arctic was investigated during two summer Arctic oceanographic campaigns (2018 and 2019) around the Svalbard Archipelago in order to unravel the differences between the Arctic background and the local anthropic settlements. Therefore, the LAA heating rate (HR) was experimentally determined. Both the chemical composition and high-resolution measurements highlighted substantial differences between the Arctic Ocean background (average eBC concentration of 11.7 ± 0.1 ng/m3) and the human settlements, among which the most impacting appeared to be Tromsø and Isfjorden (mean eBC of 99.4 ± 3.1 ng/m3). Consequently, the HR in Isfjorden (8.2 × 10−3 ± 0.3 × 10−3 K/day) was one order of magnitude higher than in the pristine background conditions (0.8 × 10−3 ± 0.9 × 10−5 K/day). Therefore, we conclude that the direct climate impact of local LAA sources on the Arctic atmosphere is not negligible and may rise in the future due to ice retreat and enhanced marine traffic.
Keywords: light-absorbing aerosols, black carbon, climate change, heating rate
Published in RUNG: 21.12.2023; Views: 600; Downloads: 5
Full text (3,57 MB)
This document has many files! More... |
14. A dual-wavelength photothermal aerosol absorption monitor : design, calibration, performance and measurements of coated sootGriša Močnik, 2023, invited lecture at foreign university Keywords: aerosol absorption, photo-thermal interferometer, absorption coefficient, black carbon, soot, aerosol coating, absorption enhancement
Published in RUNG: 05.10.2023; Views: 889; Downloads: 1
This document has many files! More... |
15. |
16. |
17. Utilizing structurally disordered AlMg-oxide phase in Cu/ZnO catalyst for efficient ▫$CO_2$▫ hydrogenation to methanolAndraž Mavrič, Gregor Žerjav, Blaž Belec, Matevž Roškarič, Matjaž Finšgar, Albin Pintar, Matjaž Valant, 2023, published scientific conference contribution abstract Keywords: carbon dioxide, methanol, catalysis
Published in RUNG: 15.09.2023; Views: 824; Downloads: 4
Full text (99,69 KB)
This document has many files! More... |
18. Highly time-resolved apportionment of carbonaceous aerosols from wildfire using the TC-BC method : camp fire 2018 case studyMatic Ivančič, Martin Rigler, Bálint Alföldy, Gašper Lavrič, Irena Ježek, Asta Gregorič, 2023, original scientific article Keywords: black carbon, brown carbon, carbonaceous aerosol, wildfire, air quality, CASS
Published in RUNG: 06.06.2023; Views: 1106; Downloads: 10
Full text (18,34 MB)
This document has many files! More... |
19. Structural disorder of AlMg-oxide phase supporting Cu/ZnO catalyst improves efficiency and selectivity for ▫$CO_2$▫ hydrogenation to methanolAndraž Mavrič, Gregor Žerjav, Blaž Belec, Matevž Roškarič, Matjaž Finšgar, Albin Pintar, Matjaž Valant, 2023, original scientific article Abstract: The performance of the Cu/ZnO catalyst system with the AlMg-oxide phase is studied for CO2 hydrogenation to methanol. The catalyst is prepared by thermal treatment of the hydrotalcite phase containing intimately mixed metal cations in the hydroxide form. CuO in the presence of ZnO and disordered AlMg-oxide phase gets easily reduced to Cu during the hydrogenation reaction. Its catalytic activity at relatively low Cu metal content (∼14 at.%) remains stable during 100 hours on stream at 260 °C with constant space-time yield for methanol (∼1.8 gMeOH gcat−1 h−1) and high methanol selectivity (>85 %) The improved performance is attributed to the neutralization of surface acidity, increased number of weak basic sites in the disordered phase, and lower tendency for coke formation.
Keywords: carbon dioxide hydrogenation, heterogenous catalysis, methanol, reducibility
Published in RUNG: 02.06.2023; Views: 1018; Downloads: 14
Full text (1,12 MB) |
20. |
