2023 |
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1. | Javier Montero-Martín; Manuel Antón; José Manuel Vaquero; Roberto Román; Javier Vaquero-Martinez; Alejandro J. P. Aparicio; Arturo Sanchez-Lorenzo Reconstruction of daily global solar radiation under all-sky and cloud-free conditions in Badajoz (Spain) since 1929 Journal Article In: International Journal of Climatology, vol. n/a, no. n/a, 2023. Abstract | Links | BibTeX | Tags: atmospheric aerosols, cloud cover, dimming/brightening, early instrumental data, surface solar radiation @article{Montero-Martín2023, Abstract This work analyses the long-term temporal variability of the annual and seasonal series of reconstructed global solar radiation for both all-sky and cloud-free conditions in Badajoz (Spain) over the 1929–2015 period. Specifically, daily values of global horizontal irradiation (GHI) for all-sky cases are derived from a semiempirical method based on the relationship between the cloud modification factor and sunshine duration records. Additionally, cloud-free situations are selected using cloud cover (CC) information recorded by surface observations. Regarding GHI linear trends for all-sky conditions, three periods are clearly identified: during the 1929–1950 period, there is a positive and statistically significant trend of +4.18?W·m?2·decade?1. It is followed by a significant dimming with a trend of ?3.72?W·m?2·decade?1 between 1951 and 1984. GHI levels increase again from 1985 to 2015 with a statistically significant trend of +2.04?W·m?2·decade?1. The seasonal trends are found to be statistically significant only in summer for all the three subperiods. With the goal to find out the possible causes of the reconstructed GHI trends, the temporal variability of the CC was also analysed. It was observed that CC has a statistically significant negative trend between 1985 and 2015 which may partially explain the GHI increase shown for this period. In contrast, not statistically significant trends were found in the annual and seasonal CC series before 1985. The long-term evolution of the GHI under cloud-free conditions exhibits the same pattern as all-sky conditions: an increase during 1929–1950, followed by a decrease in 1951–1984 and then a new increase from 1985 to 2015. Therefore, the positive (negative) linear trends in GHI reported in this study could be partially related to a decrease (increase) in the aerosol load during the analysed three subperiods. |
2022 |
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2. | Juan Carlos Antuña Sánchez Universidad de Valladolid, 2022, (dirección: Roberto Román, Ángel M. de Frutos y Victoria E. Cachorro.). Abstract | Links | BibTeX | Tags: all-sky camera, atmospheric aerosols, sky radiance @phdthesis{Sánchez2021, Atmospheric aerosols, solid or liquid particles floating in the atmosphere, play an important role in the Earth's climate, since they scatter and absorb part of the solar radiation reaching the Earth. The aerosol properties are usually obtained by measuring the diffuse solar radiation incoming in different directions (sky radiance), which is partially formed by the scattering of aerosols. The sky radiance is usually measured with photometers. A cheaper alternative to these photometers are the all-sky cameras, which capture images of the whole sky. In this doctoral thesis we propose the use of all-sky cameras to retrieve atmospheric parameters like the sky radiance and some aerosol properties, which can be obtained from these radiances. In this work, the ORION application has been developed to calibrate geometrically the all-sky cameras through the position of the stars. These calibrations are essential to locate the pixels of the camera pointing to a specific direction, such as the directions in which the sky radiance will be extracted. An all-sky camera has been geometrically calibrated with ORION, but it also has been configured to capture images in RAW format at different exposure times. The multi-exposure configuration, in addition with a exhaustive characterization of the camera (effective wavelengths, linearity, read noise, etc.), has allowed to obtain a linear high dynamic range image of the sky applying a proposed methodology. The sky radiance is proportional to the linear image obtained, so a relative sky radiance can be obtained with this proposed methodology. Once the relative sky radiances have been obtained with the all-sky camera, they have been used as input parameter in the GRASP (Generalized Retrieval of Atmosphere and Surface Properties) inversion algorithm to obtain some aerosol properties. It has been studied, using synthetic data, what aerosol properties can be derived from the relative sky radiance measured by all-sky cameras. The aerosol properties obtained with real measurements on GRASP have been compared with those independently derived by an AERONET (AErosol RObotic NETwork) photometer. This work concludes that, if the methodologies developed in this doctoral thesis are applied, a properly configured all-sky camera can be used to calculate the sky radiance, at least in a relative way, and these radiances can be also used to retrieve aerosol properties. |
2021 |
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3. | Ana Barroso; Sandra Mogo; Manuela M V G Silva; Victoria Cachorro; Ángel de Frutos Morphology, Mineralogy, and Chemistry of Atmospheric Aerosols Nearby an Active Mining Area: Aljustrel Mine (SW Portugal) Journal Article In: Atmosphere, vol. 12, no. 3, 2021, ISSN: 2073-4433. Abstract | Links | BibTeX | Tags: atmospheric aerosols, ICP-MS, Mining exploitation, SEM-EDX @article{atmos12030333, Mining activities increase contaminant levels in the environment, so it is crucial to study the particulate matter in these areas to understand the impacts on nearby urban areas and populations. This work was conducted close to the active mine of Aljustrel (Portugal), where black dust deposition is evident. PM10 samples were collected in two periods: 10–17 July and 1–10 November of 2018. Two different techniques were used: SEM-EDX for the individual characterization of the aerosols and ICP-MS to quantify the elemental concentration of 11 elements (Ca, Na, Fe, Mn, As, Cd, Cu, Sb, Pb, and Zn). In this region, the observed PM10 mass concentration was 20 to 47 µg m ?3 (July) and 4 to 23 µg m?3 (November), which is lower than the limit of 50 ?g m?3 established in the European Directive. The individual characterization of 2006 particles by SEM-EDX shows oxides (17%) and sulfides (10%), while Na, Si, Fe, S, Al, and Cu are the elements with the most representativeness in all the analyzed particles. The ICP-MS results indicate that the daily elemental concentration in the samples collected in July is higher than November, and only As exceeds the limit established for European legislation. |
2019 |
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4. | G. Titos; M. Ealo; R. Román; A. Cazorla; Y. Sola; O. Dubovik; A. Alastuey; M. Pandolfi Retrieval of aerosol properties from ceilometer and photometer measurements: long-term evaluation with in-situ data and statistical analysis at Montsec (southern Pyrenees) Conference Final ACTRIS-2 General Meeting 2019, ACTRIS Darmstadt, Germany, 2019. BibTeX | Tags: atmospheric aerosols, ceilometer, in-situ, photometer @conference{Titos2019, |
5. | J.A. Benavent-Oltra; R. Román; J.A. Casquero-Vera; D. Pérez-Ramirez; H. Lyamani; P. Ortiz-Amezcua; A.E. Bedoya-Velasquez; G. Moreira; A. Lopatin; A. Barreto; J.L Guerrero-Rascado; D. Fuertes; C. Toledano; B. Torres; O. Dubovik; P. Goloub; F.J. Olmo; L. Alados-Arboledas Using GRASP with lidar, lunar photometer and sky-images to retrieve atmospheric aerosol microphysics night-time profiles Conference Final ACTRIS-2 General Meeting 2019, ACTRIS Darmstadt, Germany, 2019. BibTeX | Tags: atmospheric aerosols, GRASP, lunar photometry, sky camera @conference{Benavent-Oltra2019b, |
2008 |
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6. | N. Prats; V. E. Cachorro; M. Sorribas; C. Toledano; A. Berjon; R. Rodrigo; B. Torres; A. de Frutos Analysis of AERONET inversion algorithm’s products at “El Arenosillo” station, southwest Spain Conference AIP Conference Proceedings, vol. 1100, no. 1, International Radiation Commission Foz do Iguaçu, Brazil, 2008, (International Radiation Symposium (IRS2008)). Abstract | Links | BibTeX | Tags: atmospheric aerosols, inversion products, physical properties, remote sensing @conference{Prats2008_02, The present work shows the main results of the analysis of AERONET inversion algorithm’s products of a sun-photometer installed at the Atmospheric Sounding Station “El Arenosillo”. This station belongs to INTA (Instituto Nacional de Técnica Aerosoespacial) and is located in the southwest of the Iberian Peninsula (37.1N – 6.7W). The aim of this work is the study of the optical aerosol properties of a long data series (August 2002 – December 2005) that are products of the AERONET inversion algorithm: volume size distribution (VSD) and complex refractive index (REF), and a wide set of derived parameters: volume concentration (VolCon), asymmetry parameter (g), single scattering albedo (SSA), etc. Version 2 of the AERONET algorithm inversion is used here. A general statistic is carried out which includes the interannual monthly behaviour of the aerosol microphysical parameters. Aerosol volume concentration shows a good correlation with the aerosol optical depth (AOD) and also the fine mode volume fraction (Vf/Vt) with the alpha Ångström exponent (AE). A characterization of the VSD and derived parameters is performed depending on aerosol type. Optical properties will be analyzed only for cases of high AOD, because of the quality assured criteria of these parameters. These cases include desert dust, showing a scattering behaviour, and biomass burning aerosol, with an absorbing character. |
Search an Article
2023 |
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1. | Reconstruction of daily global solar radiation under all-sky and cloud-free conditions in Badajoz (Spain) since 1929 Journal Article In: International Journal of Climatology, vol. n/a, no. n/a, 2023. |
2022 |
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2. | Universidad de Valladolid, 2022, (dirección: Roberto Román, Ángel M. de Frutos y Victoria E. Cachorro.). |
2021 |
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3. | Morphology, Mineralogy, and Chemistry of Atmospheric Aerosols Nearby an Active Mining Area: Aljustrel Mine (SW Portugal) Journal Article In: Atmosphere, vol. 12, no. 3, 2021, ISSN: 2073-4433. |
2019 |
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4. | Retrieval of aerosol properties from ceilometer and photometer measurements: long-term evaluation with in-situ data and statistical analysis at Montsec (southern Pyrenees) Conference Final ACTRIS-2 General Meeting 2019, ACTRIS Darmstadt, Germany, 2019. |
5. | Using GRASP with lidar, lunar photometer and sky-images to retrieve atmospheric aerosol microphysics night-time profiles Conference Final ACTRIS-2 General Meeting 2019, ACTRIS Darmstadt, Germany, 2019. |
2008 |
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6. | Analysis of AERONET inversion algorithm’s products at “El Arenosillo” station, southwest Spain Conference AIP Conference Proceedings, vol. 1100, no. 1, International Radiation Commission Foz do Iguaçu, Brazil, 2008, (International Radiation Symposium (IRS2008)). |