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The Virtual Alpine Observatory (VAO) acting to better observe, understand, forecast and react to climate change in a combined Network of European High-Altitude Research Stations
Michael Krautblatter, Griša Močnik, 2024, objavljeni povzetek znanstvenega prispevka na konferenci

Opis: The Alpine region undergoes a faster and more pronounced climate change than surrounding lowlands and, therefore, is a time machine showing the things to come in a changing climate and environment. Under the influence of a robust warming trend, witnessing an ascent of >1°C since the 1980s significant effects are visible and measurable in atmosphere, biosphere, hydrosphere, and most apparently the cryosphere. The Virtual Alpine Observatory is an assemblage comprising European Alpine Observatories, high alpine research facilities, data archives, and supercomputing centers, seamlessly interwoven through shared infrastructure and collaborative research pursuits. It is the answer to how the complex Alpine environmental system can be addressed by an interdisciplinary, cross-border collaborating research paradigm. At its core, the primary objective is to orchestrate collective endeavors aimed at observing, comprehending, and prognosticating the ramifications of climate change on the Alpine expanse. This extends to the multifaceted facets of the environment in multiple aspects. This alliance of researchers and data-gathering institutions spanning the Alpine landscape and analogous mountainous terrains in Europe propels the exploration of data patterns transcending national boundaries. In doing so, it creates a reservoir of data, knowledge and scientific approaches that surpasses the cumulative understanding derived from its individual constituents. In the upcoming discourse, we illuminate the network's future goals, composition, unveil forthcoming research initiatives, expound upon data availabilities, and deliberate on the trajectories that lie ahead for collaborative efforts. The VAO network is substantially funded by the Bavarian State Ministry of the Environment and Consumer Protection.
Ključne besede: Alpine observatory, climate change, Virtual Alpine Observatory
Objavljeno v RUNG: 18.03.2024; Ogledov: 227; Prenosov: 2
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Aerosol dust absorption : measurements with a reference instrument (PTAAM-2[lambda]) and impact on the climate as measured in airborne JATAC/CAVA-AW 2021/2022 campaigns
Jesús Yus-Díez, Luka Drinovec, Marija Bervida, Uroš Jagodič, Blaž Žibert, Griša Močnik, 2024, objavljeni povzetek znanstvenega prispevka na konferenci

Opis: Aerosol absorption coefficient measurements classically feature a very large uncertainty, especially given the absence of a reference method. The most used approach using filter-photometers is by measuring the attenuation of light through a filter where aerosols are being deposited. This presents several artifacts, with cross-sensitivity to scattering being most important at high single scattering albedo with the error exceeding 100%. We present lab campaign results where we have resuspended dust samples from different mid-latitude desert regions and measured the dust absorption and scattering coefficients, their mass concentration and the particle size distribution. The absorption coefficients were measured with two types of filter photometers: a Continuous Light Absorption Photometers (CLAP) and a multi-wavelength Aethalometer (AE33). The  dual-wavelength photo-thermal interferometer (PTAAM-2λ) was employed as the reference. Scattering coefficients were measured with an Ecotech Aurora 4000 nephelometer. The mass concentration was obtained after the weighting of filters before and after the sampling, and the particle size distribution (PSD) was measured by means of optical particle counters (Grimm 11-D).Measurements of the scattering with the nephelometer and absorption with the PTAAM-2λ we obtained the filter photometer multiple scattering parameter and cross-sensitivity to scattering as a function of the different sample properties. Moreover, by determining the mass concentration and the absorption coefficients of the samples, we derived the mass absorption cross-sections of the different dust samples, which can be linked to their size distribution as well as to their mineralogical composition.The focus of the JATAC campaign in September 2021 and September 2022 on and above Cape Verde Islands was on the calibration/validation of the ESA Aeolus satellite ALADIN lidar, however, the campaign also featured secondary scientific climate-change objectives. As part of this campaign, a light aircraft was set-up for in-situ aerosol measurements. Several flights were conducted over the Atlantic Ocean up to and above 3000 m above sea level during intense dust transport events. The aircraft was instrumented to determine the absorption coefficients using a pair of Continuous Light Absorption Photometers (CLAPs) measuring in the fine and coarse fractions separately, with parallel measurements of size distributions in these size fractions using two Grimm 11-D Optical Particle Size Spectrometers (OPSS). In addition, we performed measurements of the total and diffuse solar irradiance with a DeltaT SPN1 pyranometer.The combination of the absorption and PSD with source identification techniques enabled the separation of the contributions to  absorption by dust and black carbon. The atmospheric heating rate of these two contributions was determined by adding the irradiance measurements. Therefore, the integration of the results from the Using laboratory resuspension experiments  to interpret the airborne measurements is of great relevance for the determination  of the radiative effect of the Saharan Aerosol Layer as measured over the tropical Atlantic ocean.
Ključne besede: black carbon, mineral dust, Saharan dust, atmospheric heating rate, climate change, airborne measurements
Objavljeno v RUNG: 18.03.2024; Ogledov: 239; Prenosov: 2
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Heating rate and energy gradient from the tropics to the North Pole
Luca Ferrero, Martin Rigler, Asta Gregorič, Griša Močnik, 2024, objavljeni povzetek znanstvenega prispevka na konferenci

Opis: Absorbing aerosol species, such as Black (BC) and Brown (BrC) Carbon, are able to warm the atmosphere. The role of aerosols is one of the least clear aspects in the so called “Arctic Amplification” (AA) and up to now this was mostly modelled [1,2]. For this reason, we took part in four scientific cruises (AREX, Arctic-Expedition, summer 2018, 2019, 2021 and EUREC4A, 2020) in the North Atlantic, eastward and south-eastward of Barbados, aiming at the determination of the aerosol chemical composition and properties from the Tropics to the North Pole. The Heating Rate (HR) was experimentally determined at 1 minute time-resolution along different latitudes by means of an innovative methodology [3], obtained by cumulatively taking into account the aerosol optical properties, i.e. the absorption coefficients (measured by AE33 Aethalometer) and incident radiation (direct, diffuse and reflected) across the entire solar spectrum. The HR computed along AREX and in Milan (in the same period) were used to determine the energy gradient, due to the LAA induced heat storage at mid-latitudes, which contributes to AA through the atmospheric heat transport northward. Moreover, aerosol chemical composition was achieved by means of sampling via high volume sampler (ECHO-PUF Tecora) and analysis via ion chromatography, TCA08 for Total Carbon content, Aethalometer AE33 (for BC), ICP-OES for elements. A clear latitudinal behaviour in Black Carbon concentrations, with the highest values at low latitudes (e.g. average BC concentration in Gdansk up to 1507±75 ng/m3) and a progressive decrease moving northwards and away from the big Arctic settlements (Black Carbon concentrations within the 81st parallel: 5±1 ng/m3). According to the latitudinal behaviour of BC concentrations and solar radiation (decreases towards the north while the diffuse component increases), HR decreases noticeably towards the Arctic: e.g. higher in the harbor of Gdansk (0.290±0.010 K/day) followed by the Baltic Sea (0.04±0.01 K/day), the Norvegian Sea (0.010±0.010 K/day) and finally with the lowest values in the pure Arctic Ocean (0.003±0.001 K/day). Accordingly, the energy density added to the system by the aerosol, a positive forcing that differs by 2 orders of magnitude between mid-latitudes and North Pole was found: 347.3 ± 11.8 J/m3 (Milan), 244.8 ± 12.2 J/m3 (Gdansk) and 2.6 ± 0.2 J/m3 (80°N). These results highlight the presence of a great energy gradient between mid-latitudes and Arctic that can trigger a heat transport towards the Arctic. Moreover this was strengthen by the HR value for EUREC4A in Barbados that was 0.175±0.003 K/day. Finally, preliminary results from Antarctica collected onboard the Italian RV Laura Bassi cruising the Southern Ocean and the Ross Sea will be shown.     Acknoledgements: GEMMA Center, Project TECLA MIUR – Dipartimenti di Eccellenza 2023–2027. JPI EUREC4A-OA project. CAIAC (oCean Atmosphere Interactions in the Antarctic regions and Convergence latitude) PNRA project   References [1] Navarro, J. C. A. et al. (2016) Nat. Geosci. 9, 277–281. [2] Shindell, D. and Faluvegi, G. (2009) Nat. Geosci. 2, 294–300. [3] Ferrero, L. et al. (2018) Environ. Sci. Technol. 52, 3546 3555.
Ključne besede: blackcarbon, brown carbon, atmospheric heating rate, climate change
Objavljeno v RUNG: 18.03.2024; Ogledov: 217; Prenosov: 2
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Unmanned aerial vehicles for the Joint Aeolus Tropical Atlantic Campaign
Franco Marenco, Griša Močnik, 2023, objavljeni povzetek znanstvenega prispevka na konferenci

Opis: During June 2022, the Cyprus Institute (CyI) took part in the ASKOS experiment in Mindelo, Cape Verde, with several of Unmanned Aerial Vehicles (UAVs), fitted with a number of in-situ aerosol instruments able to profile the Saharan Air Layer between the surface and an altitude of 5,300 m. In addition to ASKOS objectives, transnational access project Diurnal vAriation of the vertically resolved siZe distribution in the Saharan Air Layer  (DAZSAL) was also carried out at the same time. The campaign aimed at validating the Aeolus L2A product in the presence of dust and marine aerosols, estimating the influence on Aeolus products of non-spherical particles, evaluating the impact of particle orientation, and study the diurnal cycle of the dust size-distribution at high altitude. In this presentation we will present and discuss the scientific objectives, the context, the Unmanned Aerial Systems (UASs) that we developed in-house, and the instruments used, together with their limitations, calibration methods, uncertainties, challenges and difficulties encountered. We will also discuss the logistical and planning challenges that such a campaign entails.Operations took place from the Cesaria Evora International Airport. The instruments deployed on-board the UAVs permitted to evaluate the height-resolved particle size-distribution between 0.1 and 40 µm and detect cases of particle orientation, to complement the observations with ground-based remote sensing set out by NOA and TROPOS. Moreover, 24 high-altitude dust samples were collected on impactors, for further analysis by Scanning Electron Microscopy. In total, 25 scientific flights were performed on 12 flying days (almost half of which at night). Five flights were conducted during Aeolus overpasses. Weather has been a determining factor for both the ground-based remote sensing operations and the UAS operation, and airport traffic has been another constraint that needed to be accounted for, in the UAS operation.
Ključne besede: UAV, mineral dust, climate change, Aeolus satellite
Objavljeno v RUNG: 21.12.2023; Ogledov: 553; Prenosov: 3
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Dust aerosols' mineralogy in the chemical transport model COSMO- MUSCAT during JATAC and comparison with lidar and in-situ data
Sofía Gómez Maqueo Anaya, Griša Močnik, 2023, objavljeni povzetek znanstvenega prispevka na konferenci

Opis: Mineral dust aerosols are composed from a complex assemblage of various minerals depending on the region they come from. Considering that minerals have their distinct physicochemical properties, differences on mineral dust aerosols climatic impact will arise as a consequence of distinct mineral content.Chemical transport models typically assume that mineral dust aerosols have uniform composition, despite the known regional variations in the mineral components. This study adds mineralogical information to the mineral dust emission scheme used in the chemical transport model, COSMO-MUSCAT.Here we show some steps of the inclusion of mineralogy to the emission scheme. Results of the simulated mineral dust aerosols are shown with their respective mineralogy from sources in Africa for an example case from the JATAC campaign in September 2021. The results of the simulated mineral dust aerosol are compared with lidar and in-situ data measured at Mindelo, Cape Verde. Furthermore, the comparison with the lidar retrieved vertical profiles at Mindelo, highlights a possible link between the mineral dust aerosol optical properties and the distinct minerals found within them.
Ključne besede: mineral dust, Aeolus satellite, climate change
Objavljeno v RUNG: 21.12.2023; Ogledov: 457; Prenosov: 2
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Airborne in-situ measurements during JATAC/CAVA-AW 2021/2022 campaigns : first climate-relevant results
Jesús Yus-Díez, Marija Bervida, Luka Drinovec, Blaž Žibert, Matevž Lenarčič, Griša Močnik, 2023, objavljeni povzetek znanstvenega prispevka na konferenci

Opis: 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.
Ključne besede: mineral dust, climate change, heating rate, black carbon, Aeolus satellite, airborne measurements
Objavljeno v RUNG: 21.12.2023; Ogledov: 523; Prenosov: 4
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Profiling Saharan airborne dust with UAV-based in-situ instrumentation during the ASKOS experiment in Cape Verde
Maria Kezoudi, Griša Močnik, 2023, objavljeni povzetek znanstvenega prispevka na konferenci

Opis: The ASKOS experimental campaign of European Space Agency (ESA) was organised by the National Observatory of Athens, and aimed at the calibration and validation of the Aeolus satellite aerosol/cloud product. Airborne observations were performed by the Climate and Atmosphere Research Centre (CARE-C) team of the Cyprus Institute at the Cesaria Evora International Airport of the island of São Vicente in Cape Verde between 10 and 30 June 2022. These in-situ aerosol measurements were conducted using the advanced Unmanned Aerial Vehicles (UAVs) of the Unmanned System Research Laboratory (USRL), equipped with specialised aerosol in-situ sensors, capturing the Saharan Air Layer (SAL) from ground up to 5.3 km Above Sea Level (ASL). The new custom-designed Composite Bird (CoBi) USRL and Skywalker UAVs (Kezoudi et al., 2021), were equipped with Optical Particle Counters (OPCs), samplers and backscatter sondes.25 UAV vertical flights were performed in total, with 11 of them during night. The altitude of the Marine Boundary Layer (MBL) was mainly observed from ground up to about 1.0 km ASL, whereas during most of the flights, high concentrations of dust particles were found between 1.5 and 5.0 km ASL. Results obtained from OPCs show the presence of particles sizing up to 20 um within MBL and up to 40 um within SAL. Further information on morphology and mineralogy of observed particles will be given by the offline analysis of collected samples under Scanning Electron Microscope (SEM). COBALD observations alongside ground-based lidar measurements agree on the presence of non-spherical particles within dust layers.  Ongoing exploitation of airborne observations along with coincident and collocated ground-based measurements will provide a complete picture for comparison with Aeolus data, particularly in relation to aerosols, where we have the most to learn.
Ključne besede: mineral dust, UAV, airborne measurements, climate change, Aeolus satellite
Objavljeno v RUNG: 21.12.2023; Ogledov: 515; Prenosov: 4
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Anthropic settlementsʹ impact on the light-absorbing aerosol concentrations and heating rate in the arctic
Niccolò Losi, Piotr Markuszewski, Martin Rigler, Asta Gregorič, Griša Močnik, Violetta Drozdowska, Przemek Makuch, Tymon Zielinski, Paulina Pakszys, Małgorzata Kitowska, 2023, izvirni znanstveni članek

Opis: 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.
Ključne besede: light-absorbing aerosols, black carbon, climate change, heating rate
Objavljeno v RUNG: 21.12.2023; Ogledov: 557; Prenosov: 5
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Measuring the Aerosol Light Absorption Coefficient - a Not-So-Easy Task With Relevance for the Global and Regional Climate
Griša Močnik, 2022, vabljeno predavanje na konferenci brez natisa

Opis: The photothermal interferometer measurement of aerosol absorption, using pump lasers (532, 1064 nm) and phase sensitive detection results in 4 and 6% measurement uncertainty. It is calibrated traceably to primary standards and thereby a potential reference.
Ključne besede: aerosol absorption, black carbon, climate change
Objavljeno v RUNG: 20.07.2022; Ogledov: 1321; Prenosov: 0
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Measuring aerosol absorption directly - PTI methods to the rescue
Griša Močnik, vabljeno predavanje na konferenci brez natisa

Ključne besede: aerosol absorption, black carbon, climate change
Objavljeno v RUNG: 19.07.2022; Ogledov: 1260; Prenosov: 0
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