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JATAC/CAVA-AW Aeolus Cal/Val airborne campaign dataset
Jesús Yus-Díez, Griša Močnik, Luka Drinovec, Marija Bervida Mačak, Blaž Žibert, Uroš Jagodič, Matevž Lenarčič, zaključena znanstvena zbirka raziskovalnih podatkov

Opis: 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:
Ključne besede: Aeolus satellite, Saharan dust, aerosol, calibration, validation
Objavljeno v RUNG: 27.09.2023; Ogledov: 410; Prenosov: 5
.pdf Celotno besedilo (77,35 KB)
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An Overview of the ASKOS Campaign in Cabo Verde
Eleni Marinou, Jesús Yus-Díez, Griša Močnik, 2023, objavljeni znanstveni prispevek na konferenci

Opis: In the framework of the ESA-NASA Joint Aeolus Tropical Atlantic Campaign (JATAC), the ASKOS experiment was implemented during the summer and autumn of 2021 and 2022. ASKOS comprised roughly 9 weeks of measurements in the Saharan dust outflow towards the North Atlantic, with operations conducted from the Cabo Verde Islands. Through its unprecedented dataset of synergistic measurements in the region, ASKOS will allow for the calibration and validation of the aerosol/cloud product from Aeolus and the preparation of the terrain for EarthCARE cal/val activities. Moreover, ASKOS marks a turning point in our ability to study Saharan dust properties and the processes affecting its atmospheric transport, as well as the link to other components of the Earth’s system, such as the effect of dust particles on cloud formation over the Eastern Atlantic and the effect of large and giant particles on radiation. This is possible through the synergy of diverse observations acquired during the experiment, which include intense 24/7 ground-based aerosol, cloud, wind, and radiation remote sensing measurements, and UAV-based aerosol in situ measurements within the Saharan air layer, up to 5.3 km altitude, offering particle size-distributions up to 40 μm as well as sample collection for mineralogical analysis. We provide an outline of the novel measurements along with the main scientific objectives of ASKOS. The campaign data will be publicly available by September of 2023 through the EVDC portal (ESA Validation Data Center).
Ključne besede: experimental campaign, remote sensing, lidar, radar, radiosondes, radiation, desert dust, in-situ, aerosol, optical properties, scattering, absorption, ASKOS
Objavljeno v RUNG: 25.09.2023; Ogledov: 313; Prenosov: 4
.pdf Celotno besedilo (4,87 MB)
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Source apportionment study on particulate air pollution in two high-altitude Bolivian cities: La Paz and El Alto
Valeria Mardoñez, Marco Pandolfi, Griša Močnik, Gaëlle Uzu, 2023, izvirni znanstveni članek

Opis: La Paz and El Alto are two fast-growing, high-altitude Bolivian cities forming the second-largest metropolitan area in the country. Located between 3200 and 4050 m a.s.l. (above sea level), these cities are home to a burgeoning population of approximately 1.8 million residents. The air quality in this conurbation is heavily influenced by urbanization; however, there are no comprehensive studies evaluating the sources of air pollution and their health impacts. Despite their proximity, the substantial variation in altitude, topography, and socioeconomic activities between La Paz and El Alto result in distinct sources, dynamics, and transport of particulate matter (PM). In this investigation, PM10 samples were collected at two urban background stations located in La Paz and El Alto between April 2016 and June 2017. The samples were later analyzed for a wide range of chemical species including numerous source tracers (OC, EC, water-soluble ions, sugar anhydrides, sugar alcohols, trace metals, and molecular organic species). The United States Environmental Protection Agency (U.S. EPA) Positive Matrix Factorization (PMF v.5.0) receptor model was employed for the source apportionment of PM10. This is one of the first source apportionment studies in South America that incorporates an extensive suite of organic markers, including levoglucosan, polycyclic aromatic hydrocarbons (PAHs), hopanes, and alkanes, alongside inorganic species. The multisite PMF resolved 11 main sources of PM. The largest annual contribution to PM10 came from the following two major sources: the ensemble of the four vehicular emissions sources (exhaust and non-exhaust), accountable for 35 % and 25 % of the measured PM in La Paz and El Alto, respectively; and dust, which contributed 20 % and 32 % to the total PM mass. Secondary aerosols accounted for 22 % (24 %) in La Paz (El Alto). Agricultural smoke resulting from biomass burning in the Bolivian lowlands and neighboring countries contributed to 9 % (8 %) of the total PM10 mass annually, increasing to 17 % (13 %) between August–October. Primary biogenic emissions were responsible for 13 % (7 %) of the measured PM10 mass. Additionally, a profile associated with open waste burning occurring from May to August was identified. Although this source contributed only to 2 % (5 %) of the total PM10 mass, it constitutes the second largest source of PAHs, which are compounds potentially hazardous to human health. Our analysis additionally resolved two different traffic-related factors, a lubricant source (not frequently identified), and a non-exhaust emissions source. Overall, this study demonstrates that PM10 concentrations in La Paz and El Alto region are predominantly influenced by a limited number of local sources. In conclusion, to improve air quality in both cities, efforts should primarily focus on addressing dust, traffic emissions, open waste burning, and biomass burning.
Ključne besede: source apportionment, particular air pollution, high altitude, positive matrix factorization, PMF
Objavljeno v RUNG: 15.09.2023; Ogledov: 340; Prenosov: 3
.pdf Celotno besedilo (3,55 MB)
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Opis: 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.
Ključne besede: dust, black carbon, aerosol
Objavljeno v RUNG: 07.03.2023; Ogledov: 849; Prenosov: 0
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Investigation of the effective transmittance of Mach-Zehnder interferometer in the multi-longitudinal-mode high-spectral-resolution lidar
Fei Gao, Fengjia Gao, Xiao Yang, Gaipan Li, Li Wang, Meng Wang, Dengxin Hua, Griša Močnik, Samo Stanič, 2022, izvirni znanstveni članek

Opis: Effective transmittance is an important parameter of Mach-Zehnder interferometer in the retrieval of aerosol optical properties using the multi-longitudinal-mode high-spectral-resolution lidar, which is a function of the complex degree of coherence. In this paper, we retrieve the parameter of the complex degree of coherence for the multi-longitudinal-mode laser from the theoretical analysis, optical simulation and experimental measurements, which are 0.726, 0.678 and 0.453 using the Mach-Zehnder interferometer with the optimal optical path difference of two times of laser optical cavity length (∼1000 mm) and under the light illumination of the high power Nd:YAG laser with the mode number of 101 and mode interval of 300 MHz under the condition of laser linewidth of 1 cm−1 (30 GHz). The preliminary measurement results of aerosol optical properties using the constructing multi-longitudinal-mode high-spectral-resolution lidar show that the difference of the complex degree of coherence retrieved from the presented methods results in the relative error of 40% in the aerosol backscattering coefficient with thin cloud layer and 90% with the presence of dense aerosol layer.
Ključne besede: effective transmittance, Mach-Zehnder interferometer, Multi-logitudinal-mode laser, High-spectral-resolution lidar
Objavljeno v RUNG: 20.09.2022; Ogledov: 1063; Prenosov: 0
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Aeolus calibration, validation and science campaigns
Thorsten Fehr, Vassilis Amiridis, Sebastian Bley, Philippe Cocquerez, Christian Lemmerz, Griša Močnik, Gail Skofronick-Jackson, Anne Grete Straume, 2020, objavljeni povzetek znanstvenega prispevka na konferenci

Opis: Since 2007, a series of ESA supported airborne campaigns have been essential to the development of the Aeolus Doppler Wind Lidar satellite mission, which was successfully launched on 22 September 2018 and is providing a novel wind and aerosol profile data. A core element of the Aeolus Cal/Val activities is DLR’s A2D wind lidar on-board the DLR Falcon aircraft, an airborne demonstrator for the Aeolus ALADIN satellite instrument flown in combination with the 2-µm Doppler Wind Lidar reference system. Following the pre-launch WindVal-I and –II campaigns in 2015 and 2016, a number of calibration and validation campaigns have been successfully implemented: WindVal-III providing early Cal/Val results in November 2018 only three months after the Aeolus launch, AVATAR-E in May 2019 focussing on the Cal/Val over Central Europe, and AVATAR-I in September 2019 providing Cal/Val information in the North Atlantic and Arctic flying from Iceland. The airborne validation is also being supported through balloon flights in the tropical UTLS and lower stratosphere in the frame of the CNES Stratéole-2 stratospheric balloon activities. In the frame of the ESA supported pre-Stratéole-2 campaign, eight stratospheric balloons have been launched from the Seychelles in November/December 2019 providing unique upper level wind data for the Aeolus validation. The largest impact of the Aeolus observations is expected in the Tropics, and in particular over the Tropical oceans, where only a limited number of wind profile information is provided by ground based observations. Aeolus provides key direct measurements which are of importance to correctly constrain the wind fields in models. In addition, Aeolus observations have the potential to further enhance our current knowledge on aerosols and clouds by globally providing optical properties products that include atmospheric backscatter and extinction coefficient profiles, lidar ratio profiles and scene classification. In the tropics, a particularly interesting case is the outflow of Saharan dust and its impact on micro-physics in tropical cloud systems. The region off the coast of West Africa allows the study of the Saharan Aerosol layer, African Easterly Waves and Jets, Tropical Easterly Jet, as well as the deep convection in ITCZ. Together with international partners, ESA is currently implementing a Tropical campaign in July 2020 with its base in Cape Verde that comprises both airborne and ground-based activities addressing the tropical winds and aerosol validation, as well as science objectives. The airborne component includes the DLR Falcon-20 carrying the A2D and 2-µm Doppler Wind lidars, the NASA P-3 Orion with the DAWN and HALO lidar systems, the APR Ku-, Ka- and W-band Doppler radar and drop sondes, and a Slovenian small aircraft providing in-situ information from aethalometers, nephelometers and optical particle counters. The ground-based component led by the National Observatory of Athens is a collaboration of European teams providing aerosol and cloud measurements with a range of lidar, radar and radiometer systems, as well as a drone providing in-situ aerosol observations. In addition, the participation airborne capabilities by NOAA and LATMOS/Meteo France are currently being investigated. This paper will provide a summary of the Aeolus campaign focussing on the planned tropical campaign.
Ključne besede: Aeolus satellite, ALADIN, aerosol, validation
Objavljeno v RUNG: 23.08.2022; Ogledov: 979; Prenosov: 44
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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: 1027; Prenosov: 0
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