Mission
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The Atmospheric Optics Group of Valladolid University (GOA-UVa) is involved in the study of atmospheric components, mainly aerosols, with optical methods. The GOA calibration facility is devoted to radiometric calibration of optical instrumentations such as photometers, and it is part of the AERONET-Europe Central Facility, partially funded by the European Union. As a university group, our researchers carry out educational and training activity (graduate, master and PhD thesis). In this site you can find information about the work of the group, members, research lines, publications, projects, vacancies, etc. |
Latests 5 Publications
2021
1.
J A Benavent-Oltra; J A Casquero-Vera; R Román; H Lyamani; D Pérez-Ramírez; M J Granados-Muñoz; M Herrera; A Cazorla; G Titos; P Ortiz-Amezcua; A E Bedoya-Velásquez; G de Arruda Moreira; N Pérez; A Alastuey; O Dubovik; J L Guerrero-Rascado; F J Olmo-Reyes; L Alados-Arboledas
Overview of the SLOPE I and II campaigns: aerosol properties retrieved with lidar and sun--sky photometer measurements Journal Article
In: Atmospheric Chemistry and Physics, 21 (12), pp. 9269-9287, 2021.
@article{Benavent-Oltra2021,
title = {Overview of the SLOPE I and II campaigns: aerosol properties retrieved with lidar and sun--sky photometer measurements},
author = {J A Benavent-Oltra and J A Casquero-Vera and R Román and H Lyamani and D Pérez-Ramírez and M J Granados-Muñoz and M Herrera and A Cazorla and G Titos and P Ortiz-Amezcua and A E Bedoya-Velásquez and G de Arruda Moreira and N Pérez and A Alastuey and O Dubovik and J L Guerrero-Rascado and F J Olmo-Reyes and L Alados-Arboledas},
url = {https://acp.copernicus.org/articles/21/9269/2021/},
doi = {10.5194/acp-21-9269-2021},
year = {2021},
date = {2021-06-17},
journal = {Atmospheric Chemistry and Physics},
volume = {21},
number = {12},
pages = {9269-9287},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
2.
J C Antuña-Sánchez; R Román; V E Cachorro; C Toledano; C López; R González; D Mateos; A Calle; Á M de Frutos
Relative sky radiance from multi-exposure all-sky camera images Journal Article
In: Atmospheric Measurement Techniques, 14 (3), pp. 2201–2217, 2021.
@article{amt-14-2201-2021,
title = {Relative sky radiance from multi-exposure all-sky camera images},
author = {J C Antuña-Sánchez and R Román and V E Cachorro and C Toledano and C López and R González and D Mateos and A Calle and Á M de Frutos},
url = {https://amt.copernicus.org/articles/14/2201/2021/},
doi = {10.5194/amt-14-2201-2021},
year = {2021},
date = {2021-03-22},
journal = {Atmospheric Measurement Techniques},
volume = {14},
number = {3},
pages = {2201--2217},
abstract = {All-sky cameras are frequently used to detect cloud cover; however, this work explores the use of these instruments for the more complex purpose of extracting relative sky radiances. An all-sky camera (SONA202-NF model) with three colour filters narrower than usual for this kind of cameras is configured to capture raw images at seven exposure times. A detailed camera characterization of the black level, readout noise, hot pixels and linear response is carried out. A methodology is proposed to obtain a linear high dynamic range (HDR) image and its uncertainty, which represents the relative sky radiance (in arbitrary units) maps at three effective wavelengths. The relative sky radiances are extracted from these maps and normalized by dividing every radiance of one channel by the sum of all radiances at this channel. Then, the normalized radiances are compared with the sky radiance measured at different sky points by a sun and sky photometer belonging to the Aerosol Robotic Network (AERONET). The camera radiances correlate with photometer ones except for scattering angles below 10?, which is probably due to some light reflections on the fisheye lens and camera dome. Camera and photometer wavelengths are not coincident; hence, camera radiances are also compared with sky radiances simulated by a radiative transfer model at the same camera effective wavelengths. This comparison reveals an uncertainty on the normalized camera radiances of about 3.3?%, 4.3?% and 5.3?% for 467, 536 and 605?nm, respectively, if specific quality criteria are applied.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
All-sky cameras are frequently used to detect cloud cover; however, this work explores the use of these instruments for the more complex purpose of extracting relative sky radiances. An all-sky camera (SONA202-NF model) with three colour filters narrower than usual for this kind of cameras is configured to capture raw images at seven exposure times. A detailed camera characterization of the black level, readout noise, hot pixels and linear response is carried out. A methodology is proposed to obtain a linear high dynamic range (HDR) image and its uncertainty, which represents the relative sky radiance (in arbitrary units) maps at three effective wavelengths. The relative sky radiances are extracted from these maps and normalized by dividing every radiance of one channel by the sum of all radiances at this channel. Then, the normalized radiances are compared with the sky radiance measured at different sky points by a sun and sky photometer belonging to the Aerosol Robotic Network (AERONET). The camera radiances correlate with photometer ones except for scattering angles below 10?, which is probably due to some light reflections on the fisheye lens and camera dome. Camera and photometer wavelengths are not coincident; hence, camera radiances are also compared with sky radiances simulated by a radiative transfer model at the same camera effective wavelengths. This comparison reveals an uncertainty on the normalized camera radiances of about 3.3?%, 4.3?% and 5.3?% for 467, 536 and 605?nm, respectively, if specific quality criteria are applied.
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, 12 (3), 2021, ISSN: 2073-4433.
@article{atmos12030333,
title = {Morphology, Mineralogy, and Chemistry of Atmospheric Aerosols Nearby an Active Mining Area: Aljustrel Mine (SW Portugal)},
author = {Ana Barroso and Sandra Mogo and Manuela M V G Silva and Victoria Cachorro and Ángel de Frutos},
url = {https://www.mdpi.com/2073-4433/12/3/333},
doi = {10.3390/atmos12030333},
issn = {2073-4433},
year = {2021},
date = {2021-03-05},
journal = {Atmosphere},
volume = {12},
number = {3},
abstract = {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.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
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.
4.
AE Bedoya-Velásquez; M Herreras-Giralda; R Román; M Wiegner; S Lefebvre; C Toledano; T Huet; R Ceolato
Ceilometer inversion method using water-vapor correction from co-located microwave radiometer for aerosol retrievals Journal Article
In: Atmospheric Research, pp. 105379, 2021.
@article{bedoya2021ceilometer,
title = {Ceilometer inversion method using water-vapor correction from co-located microwave radiometer for aerosol retrievals},
author = {AE Bedoya-Velásquez and M Herreras-Giralda and R Román and M Wiegner and S Lefebvre and C Toledano and T Huet and R Ceolato},
doi = {10.1016/j.atmosres.2020.105379},
year = {2021},
date = {2021-03-01},
journal = {Atmospheric Research},
pages = {105379},
publisher = {Elsevier},
abstract = {Recent ceilometer models are more sensitive to aerosols, which is increasing the interest in these instruments to retrieve aerosol optical and microphysical properties. In this paper, a new methodology is proposed to retrieve aerosol vertical extinction and backscatter profiles from a Vaisala ceilometer CL51 model. This methodology is based in two parts: first, a signal pre-processing with a suppression of the dark current and background noises, and a correction of the water vapor absorption using near-real-time temperature and absolute humidity (AH) profiles from a co-located Microwave radiometer (MWR). The measured dark current shows a height-dependence from 11?km agl to the end of the profile. From the water vapor correction, it was seen that the raw ceilometer signal overestimates the water vapor corrected one, mainly below 1?km agl. Second part is based on an iterative Klett-based algorithm making use of AERONET (AErosol RObotic NETwork) AOD (Aerosol Optical Depth) and ceilometer profiles as inputs to retrieve the extinction and backscatter profiles. The sensitivity of the aerosol retrievals to the use of modelled temperature and absolute humidity from HYSPLIT to correct water vapor absorption, instead of MWR measurements, is studied. The absolute errors found in temperature and AH profiles leads to errors in the pre-processed range corrected signals up to 9%, and then in particle backscatter (?p) and particle extinction (?p) coefficients up to 2.2 % and 25 %, respectively.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Recent ceilometer models are more sensitive to aerosols, which is increasing the interest in these instruments to retrieve aerosol optical and microphysical properties. In this paper, a new methodology is proposed to retrieve aerosol vertical extinction and backscatter profiles from a Vaisala ceilometer CL51 model. This methodology is based in two parts: first, a signal pre-processing with a suppression of the dark current and background noises, and a correction of the water vapor absorption using near-real-time temperature and absolute humidity (AH) profiles from a co-located Microwave radiometer (MWR). The measured dark current shows a height-dependence from 11?km agl to the end of the profile. From the water vapor correction, it was seen that the raw ceilometer signal overestimates the water vapor corrected one, mainly below 1?km agl. Second part is based on an iterative Klett-based algorithm making use of AERONET (AErosol RObotic NETwork) AOD (Aerosol Optical Depth) and ceilometer profiles as inputs to retrieve the extinction and backscatter profiles. The sensitivity of the aerosol retrievals to the use of modelled temperature and absolute humidity from HYSPLIT to correct water vapor absorption, instead of MWR measurements, is studied. The absolute errors found in temperature and AH profiles leads to errors in the pre-processed range corrected signals up to 9%, and then in particle backscatter (?p) and particle extinction (?p) coefficients up to 2.2 % and 25 %, respectively.
5.
Juan Carlos Antuña-Sánchez; René Estevan; Roberto Román; Juan Carlos Antuña-Marrero; Victoria E Cachorro; Albeth Rodríguez Vega; Ángel M de Frutos
Solar Radiation Climatology in Camagüey, Cuba (1981–2016) Journal Article
In: Remote Sensing, 13 (2), 2021, ISSN: 2072-4292.
@article{rs13020169,
title = {Solar Radiation Climatology in Camagüey, Cuba (1981–2016)},
author = {Juan Carlos Antuña-Sánchez and René Estevan and Roberto Román and Juan Carlos Antuña-Marrero and Victoria E Cachorro and Albeth Rodríguez Vega and Ángel M de Frutos},
url = {https://www.mdpi.com/2072-4292/13/2/169},
doi = {10.3390/rs13020169},
issn = {2072-4292},
year = {2021},
date = {2021-01-01},
journal = {Remote Sensing},
volume = {13},
number = {2},
abstract = {The transition to renewable energies is an unavoidable step to guarantee a peaceful and sustainable future for humankind. Although solar radiation is one of the main sources of renewable energy, there are broad regions of the planet where it has not been characterized appropriately to provide the necessary information for regional and local planning and design of the different solar powered systems. The Caribbean, and Cuba in particular, lacked until very recently at least one long-term series of surface solar radiation measurements. Here we present the first long-term records of solar radiation for this region. Solar radiation measurements manually conducted and recorded on paper were rescued, reprocessed and quality controlled to develop the solar radiation climatology at the Actinometrical Station of Camagüey, in Cuba (21.422°N; 77.850°W; 122 m a.s.l.) for the period 1981–2016. The diurnal cycle based on the average hourly values of the global, direct and diffuse horizontal variables for the entire period have been determined and analyzed showing the dependence on solar zenith angle (SZA) and clouds. The annual cycle of global solar component given by the mean monthly daily values presents two maxima, one in April and another one in July with values of 5.06 and 4.91 kWh m−2, respectively (18.23 and 17.67 MJ m−2 per day for insolation), and the minimum in December (3.15 kWh m−2 or 11.33 MJ m−2). The maxima are governed by the direct solar components and are modulated by cloudiness. Both, diurnal and annual cycles of the diffuse solar component show a smoothed bell shaped behavior. In general solar radiation at this station presents a strong influence of clouds, with little seasonal variation but with higher values during the rainy season. Daily global radiation annual averages showed its maximum value in the year 1983, with 17.45 MJ m−2 explained by very low cloudiness this year, and the minimum value was reported in 2009 with a value of 12.43 MJ m−2 that could not explained by the cloud coverage or the aerosols optical depths registered that year. The effects of the 1982 El Chichón and 1991 Mount Pinatubo volcanic eruptions on the solar radiation variables at Camagüey are also shown and discussed. The results achieved in this study shown the characteristics of solar radiation in this area and their potential for solar power applications.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The transition to renewable energies is an unavoidable step to guarantee a peaceful and sustainable future for humankind. Although solar radiation is one of the main sources of renewable energy, there are broad regions of the planet where it has not been characterized appropriately to provide the necessary information for regional and local planning and design of the different solar powered systems. The Caribbean, and Cuba in particular, lacked until very recently at least one long-term series of surface solar radiation measurements. Here we present the first long-term records of solar radiation for this region. Solar radiation measurements manually conducted and recorded on paper were rescued, reprocessed and quality controlled to develop the solar radiation climatology at the Actinometrical Station of Camagüey, in Cuba (21.422°N; 77.850°W; 122 m a.s.l.) for the period 1981–2016. The diurnal cycle based on the average hourly values of the global, direct and diffuse horizontal variables for the entire period have been determined and analyzed showing the dependence on solar zenith angle (SZA) and clouds. The annual cycle of global solar component given by the mean monthly daily values presents two maxima, one in April and another one in July with values of 5.06 and 4.91 kWh m−2, respectively (18.23 and 17.67 MJ m−2 per day for insolation), and the minimum in December (3.15 kWh m−2 or 11.33 MJ m−2). The maxima are governed by the direct solar components and are modulated by cloudiness. Both, diurnal and annual cycles of the diffuse solar component show a smoothed bell shaped behavior. In general solar radiation at this station presents a strong influence of clouds, with little seasonal variation but with higher values during the rainy season. Daily global radiation annual averages showed its maximum value in the year 1983, with 17.45 MJ m−2 explained by very low cloudiness this year, and the minimum value was reported in 2009 with a value of 12.43 MJ m−2 that could not explained by the cloud coverage or the aerosols optical depths registered that year. The effects of the 1982 El Chichón and 1991 Mount Pinatubo volcanic eruptions on the solar radiation variables at Camagüey are also shown and discussed. The results achieved in this study shown the characteristics of solar radiation in this area and their potential for solar power applications.