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@article{García2022,

title = {La erupción volcánica de La Palma y el papel de la Agencia Estatal de Meteorología},

author = {García, O. and Suárez, D. and Cuevas, E. and Ramos, R. and Barreto, Á. and Hernández, M. and Quintero, V. and Toledano, C. and Sicard, M. and Córdoba-Jabonero, C. and Riz, V. and Roininen, R. and López, C. and Vilches, J. and Weiss, M. and Carreño, V. and Taquet, N. and Boulesteix, T. and Fraile, E. and Torres, C. and Prats, N. and Alcántara, A. and León, S. and Rivas, P. and Álvarez, Ó. and Parra, F. and de Luis, J. and González, C. and Armas, C. and Romero, P. and de Bustos, J. and Redondas, A. and Marrero, C. and Milford, C. and Román, R. and González, R. and López-Cayuela, M. and Carvajal-Pérez, C. and Chinea, N. and García, R. and Almansa, F. and González, Y. and Bullón, F. and Poggio, M. and Rivera, C. and Bayo, C. and Rey, F.},

url = {https://pub.ame-web.org/index.php/TyC/article/view/2516},

year  = {2022},

date = {2022-05-04},

journal = { Revista Tiempo Y Clima},

volume = {5},

number = {76},

abstract = {Durante la erupción del volcán de Cumbre Vieja, en la isla de La Palma en 2021, la Agencia Estatal de Meteorología (AEMET), en calidad de Servicio Nacional y Autoridad Meteorológica del Estado, prestó diferentes servicios de apoyo al Comité Científico y al Comité Asesor del Plan de Emergencias Volcánicas de Canarias (PEVOLCA). Parte de sus actividades abarcaron la vigilancia y predicción meteorológica, la monitorización y predicción del transporte del penacho volcánico, y la valoración del impacto de las emisiones de gases y cenizas de la erupción volcánica en la calidad del aire en la isla de La Palma y en la región de Canarias.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Antuña-Sánchez2022,

title = {ORION software tool for the geometrical calibration of all-sky cameras},

author = {J.C. Antuña-Sánchez and R. Román and J.L. Bosch and C. Toledano and D. Mateos and R. González and V.E. Cachorro and Ángel de Frutos},

doi = {10.1371/journal.pone.0265959},

year  = {2022},

date = {2022-03-31},

urldate = {2022-03-31},

journal = {PLoS ONE 17(3)},

abstract = {This paper presents the software application ORION (All-sky camera geOmetry calibRation from star positIONs). This software has been developed with the aim of providing geometrical calibration to all-sky cameras, i.e. assess which sky coordinates (zenith and azimuth angles) correspond to each camera pixel. It is useful to locate bodies over the celestial vault, like stars and planets, in the camera images. The user needs to feed ORION with a set of cloud-free sky images captured at night-time for obtaining the calibration matrices. ORION searches the position of various stars in the sky images. This search can be automatic or manual. The sky coordinates of the stars and the corresponding pixel positions in the camera images are used together to determine the calibration matrices. The calibration is based on three parameters: the pixel position of the sky zenith in the image; the shift angle of the azimuth viewed by the camera with respect to the real North; and the relationship between the sky zenith angle and the pixel radial distance regards to the sky zenith in the image. In addition, ORION includes other features to facilitate its use, such as the check of the accuracy of the calibration. An example of ORION application is shown, obtaining the calibration matrices for a set of images and studying the accuracy of the calibration to predict a star position. Accuracy is about 9.0 arcmin for the analyzed example using a camera with average resolution of 5.4 arcmin/pixel (about 1.7 pixels).},

keywords = {all-sky camera, clouds, image analylis, polynomials, stars},

pubstate = {published},

tppubtype = {article}

}

@article{Cachorro2022,

title = {SSolar-GOA v1.0: a simple, fast, and accurate Spectral SOLAR radiative transfer model for clear skies},

author = {V. E. Cachorro and J. C. Antuña-Sanchez and Á. M. Frutos},

url = {https://gmd.copernicus.org/articles/15/1689/2022/},

doi = {10.5194/gmd-15-1689-2022},

year  = {2022},

date = {2022-02-25},

urldate = {2022-02-25},

journal = {Geoscientific Model Development},

volume = {15},

number = {4},

pages = {1689--1712},

abstract = {The aim of this work is to describe the features of and to validate a simple, fast, accurate, and physically based spectral radiative transfer model in the solar wavelength range under clear skies. The model, named SSolar-GOA (the first “S” stands for “spectral”), was developed to evaluate the instantaneous values of spectral solar irradiances at ground level or at a given altitude of the atmosphere. The model requirements are designed based on the simplicity of the analytical expressions for the transmittance functions in order to be easily replicated and applied by a wide community of users for many different applications (atmospheric and environmental research studies, satellite remote sensing, solar energy, agronomy and forestry, ecology, and others). Although spectral, the model runs quickly and has sufficient accuracy for the evaluation of solar irradiances with a spectral resolution of 1–10?nm. The model assumes a single mixed molecule–aerosol scattering layer where the original Ambartsumian method of “adding layers” in a one-dimensional medium is applied, obtaining a parameterized expression for the total transmittance of scattering. Absorption by the different atmospheric gases follows “band model” parameterized expressions. The input parameters must be realistic and easily available since the spectral aerosol optical depth (AOD) is the main driver of the model. The validation of the SSolar-GOA model has been carried out through comparison with simulated irradiance data from the libRadtran package and with direct and global spectra measured by spectroradiometers. Thousands of spectra under clear skies have been compared for different atmospheric conditions and solar zenith angles (SZA). The SSolar-GOA is validated by a quantitative comparison with libRadtran, showing that it underestimates direct normal, global, and diffuse spectral components with relative differences of +1?% (RMSE?%?=?4.6–8), +3?% (RMSE?%?=?5.3–8), and 8?% (RMSE?%?=?9.3–9.6), respectively, when the SZA varies from 6 to 60?. Compared with the measured irradiance data of the LI-1800 and ASD spectroradiometers, the relative differences of direct normal and global components are within the overall experimental error, about ±2?%–12?% (RMSE?%?=?5–8.3), with underestimated or overestimated values. The diffuse component presents the highest degree of relative difference that can reach ±20?%–30?% and RMSE of 25?%–50?%. The relative differences depend strongly on the spectral solar region analysed and the SZA, but the high values of RMSE are due to the artifice generated by the different spectral resolution of the absorption coefficients of both models. Model approach errors combined with calibration instrument errors may explain the observed differences. The SSolar-GOA v1.0 is implemented in Python and open-source licensing.},

keywords = {model, Radiative transfer, Solar radiation},

pubstate = {published},

tppubtype = {article}

}

@article{Antuña-Marrero2022,

title = {Integrated water vapor over the Arctic: Comparison between radiosondes and sun photometer observations},

author = {Juan Carlos Antuña-Marrero and Roberto Román and Victoria E. Cachorro and David Mateos and Carlos Toledano and Abel Calle and Juan Carlos Antuña-Sánchez and Javier Vaquero-Martínez and Manuel Antón and Ángel M. Frutos Baraja},

url = {https://www.sciencedirect.com/science/article/pii/S016980952200045X},

doi = {https://doi.org/10.1016/j.atmosres.2022.106059},

issn = {0169-8095},

year  = {2022},

date = {2022-02-02},

urldate = {2022-01-01},

journal = {Atmospheric Research},

volume = {270},

pages = {106059},

abstract = {The amplification of global warming because of the feedbacks associated with the increase in atmospheric moisture and the decrease in sea ice and snow cover in the Arctic is currently the focus of scientists, policy makers and society. The amplification of global warming is the response to increases in precipitation originally caused by climate change. Arctic predominant increases in specific humidity and precipitation have been documented by observations. In comparison, evapotranspiration in the Arctic is poorly known, in part, because the spatial and temporal sparsity of accurate in situ and remote sensing observations. Although more than 20 observations sites in the Arctic are available, where AERONET sun photometer integrated water vapor (IWV) measurements have been conducted, that information have been barely used. Here, we present a comparison of IWV observations from radiosondes and AERONET sun photometers at ten sites located across the Arctic with the goal to document the feasibility of that set of observations to contribute to the ongoing and future research on polar regions. Sun photometer IWV observations are averaged for three-time windows; 30 min, 6 and 24 h. The predominant dry bias of AERONET IWV observations with respect to radiosondes, identified at tropical and midlatitudes, is also present in the Arctic. The statistics of the comparison show robust results at eight of the ten sites, with precision and accuracy magnitudes below 8 and 2% respectively. The possible causes of the less robust results at the other two sites are discussed. In addition, the impact of selecting other temporal coincidence windows in the average sun photometer IWV used in the comparison were tested. Auto-correlation in diurnal sun photometer IWV could produce appreciable bias in the statistics used for the comparison. We suggest using only one pair of values per day, consisting in the daily mean IWV sun photometer and the IWV radiosonde observation value. This feature should be valid also for comparison of IWV from sun photometer and other instruments. Maximum 10% error level of IWV from sun photometer observations, when compared with radiosondes, have been found for the Arctic. It is in the same order of magnitude than at tropical and middle latitudes locations. It has been demonstrated the feasibility of AERONET IWV observations in the Arctic for research on this variable. AERONET standard instruments and its centralized-standard processing algorithm allow its IWV observations to be considered a relative standard dataset for the re-calibration of other instrumental IWV observations assuming radiosondes as the absolute standard dataset.},

keywords = {AERONET, Arctic, Integrated water vapor, radiosonde, Sun photometer},

pubstate = {published},

tppubtype = {article}

}

@article{Román2022,

title = {Retrieval of aerosol properties using relative radiance measurements from an all-sky camera},

author = {R. Román and J. C. Antuña-Sánchez and V. E. Cachorro and C. Toledano and B. Torres and D. Mateos and D. Fuertes and C. López and R. González and T. Lapionok and M. Herreras-Giralda and O. Dubovik and Á. M. Frutos},

url = {https://amt.copernicus.org/articles/15/407/2022/},

doi = {10.5194/amt-15-407-2022},

year  = {2022},

date = {2022-01-27},

urldate = {2022-01-01},

journal = {Atmospheric Measurement Techniques},

volume = {15},

number = {2},

pages = {407--433},

abstract = {This paper explores the potential of all-sky cameras to retrieve aerosol properties with the GRASP code (Generalized Retrieval of Atmosphere and Surface Properties). To this end, normalized sky radiances (NSRs) extracted from an all-sky camera at three effective wavelengths (467, 536 and 605?nm) are used in this study. NSR observations are a set of relative (uncalibrated) sky radiances in arbitrary units. NSR observations have been simulated for different aerosol loads and types with the forward radiative transfer module of GRASP, indicating that NSR observations contain information about the aerosol type, as well as about the aerosol optical depth (AOD), at least for low and moderate aerosol loads. An additional sensitivity study with synthetic data has been carried out to quantify the theoretical accuracy and precision of the aerosol properties (AOD, size distribution parameters, etc.) retrieved by GRASP using NSR observations as input. As a result, the theoretical accuracy of AOD is within ±0.02 for AOD values lower than or equal to 0.4, while the theoretical precision goes from 0.01 to 0.05 when AOD at 467?nm varies from 0.1 to 0.5. NSR measurements recorded at Valladolid (Spain) with an all-sky camera for more than 2 years have been inverted with GRASP. The retrieved aerosol properties are compared with independent values provided by co-located AERONET (AErosol RObotic NETwork) measurements. AODs from both data sets correlate with determination coefficient (r2) values of about 0.87. Finally, the novel multi-pixel approach of GRASP is applied to daily camera radiances together by constraining the temporal variation in certain aerosol properties. This temporal linkage (multi-pixel approach) provides promising results, reducing the highly temporal variation in some aerosol properties retrieved with the standard (one by one or single-pixel) approach. This work implies an advance in the use of all-sky cameras for the retrieval of aerosol properties.},

keywords = {aerosol, all-sky camera, GRASP, retrieval},

pubstate = {published},

tppubtype = {article}

}

@article{ClimatologyofaerosolsovertheCaribbeanislandsaerosoltypessynopticpatternsandtransport,

title = {Climatology of aerosols over the Caribbean islands: aerosol types, synoptic patterns and transport},

author = {Albeht Rodríguez-Vega and Juan Carlos Antuña-Marrero and David Barriopedro and Ricardo García-Herrera and Victoria E. Cachorro Revilla and Ángel Frutos Baraja and Juan Carlos Antuña-Sánchez},

url = {https://journals.ametsoc.org/view/journals/apme/aop/JAMC-D-21-0015.1/JAMC-D-21-0015.1.xml},

doi = {10.1175/JAMC-D-21-0015.1},

year  = {2022},

date = {2022-01-01},

urldate = {2022-01-01},

journal = {Journal of Applied Meteorology and Climatology},

publisher = {American Meteorological Society},

address = {Boston MA, USA},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{García2021b,

title = {Twenty years of ground-based NDACC FTIR spectrometry at Izaña Observatory -- overview and long-term comparison to other techniques},

author = {O. E. García and M. Schneider and E. Sepúlveda and F. Hase and T. Blumenstock and E. Cuevas and R. Ramos and J. Gross and S. Barthlott and A. N. Röhling and E. Sanromá and Y. González and Á. J. Gómez-Peláez and M. Navarro-Comas and O. Puentedura and M. Yela and A. Redondas and V. Carre no and S. F. León-Luis and E. Reyes and R. D. García and P. P. Rivas and P. M. Romero-Campos and C. Torres and N. Prats and M. Hernández and C. López},

url = {https://acp.copernicus.org/articles/21/15519/2021/},

doi = {10.5194/acp-21-15519-2021},

year  = {2021},

date = {2021-10-18},

urldate = {2021-01-01},

journal = {Atmospheric Chemistry and Physics},

volume = {21},

number = {20},

pages = {15519--15554},

keywords = {long-term comparison, NDACC FTIR},

pubstate = {published},

tppubtype = {article}

}

@article{Antuña-Marrero2021,

title = {Recovery of the first ever multi-year lidar dataset of the stratospheric aerosol layer, from Lexington, MA, and Fairbanks, AK, January 1964 to July 1965},

author = {J. C. Antuña-Marrero and G. W. Mann and J. Barnes and A. Rodríguez-Vega and S. Shallcross and S. S. Dhomse and G. Fiocco and G. W. Grams},

url = {https://essd.copernicus.org/articles/13/4407/2021/},

doi = {10.5194/essd-13-4407-2021},

year  = {2021},

date = {2021-09-08},

urldate = {2021-01-01},

journal = {Earth System Science Data},

volume = {13},

number = {9},

pages = {4407--4423},

abstract = {We report the recovery and processing methodology of the first ever multi-year lidar dataset of the stratospheric aerosol layer. A Q-switched ruby lidar measured 66 vertical profiles of 694?nm attenuated backscatter at Lexington, Massachusetts, between January 1964 and August 1965, with an additional nine profile measurements conducted from College, Alaska, during July and August 1964. We describe the processing of the recovered lidar backscattering ratio profiles to produce mid-visible (532?nm) stratospheric aerosol extinction profiles (sAEP532) and stratospheric aerosol optical depth (sAOD532) measurements, utilizing a number of contemporary measurements of several different atmospheric variables. Stratospheric soundings of temperature and pressure generate an accurate local molecular backscattering profile, with nearby ozone soundings determining the ozone absorption, which are used to correct for two-way ozone transmittance. Two-way aerosol transmittance corrections are also applied based on nearby observations of total aerosol optical depth (across the troposphere and stratosphere) from sun photometer measurements. We show that accounting for these two-way transmittance effects substantially increases the magnitude of the 1964/1965 stratospheric aerosol layer's optical thickness in the Northern Hemisphere mid-latitudes, then ??50?% larger than represented in the Coupled Model Intercomparison Project 6 (CMIP6) volcanic forcing dataset. Compared to the uncorrected dataset, the combined transmittance correction increases the sAOD532 by up to 66?% for Lexington and up to 27?% for Fairbanks, as well as individual sAEP532 adjustments of similar magnitude. Comparisons with the few contemporary measurements available show better agreement with the corrected two-way transmittance values.



Within the January 1964 to August 1965 measurement time span, the corrected Lexington sAOD532 time series is substantially above 0.05 in three distinct periods, October 1964, March 1965, and May–June 1965, whereas the 6 nights the lidar measured in December 1964 and January 1965 had sAOD values of at most ??0.03. The comparison with interactive stratospheric aerosol model simulations of the Agung aerosol cloud shows that, although substantial variation in mid-latitude sAOD532 are expected from the seasonal cycle in the stratospheric circulation, the Agung cloud's dispersion from the tropics would have been at its strongest in winter and weakest in summer. The increasing trend in sAOD from January to July 1965, also considering the large variability, suggests that the observed variations are from a different source than Agung, possibly from one or both of the two eruptions that occurred in 1964/1965 with a Volcanic Explosivity Index (VEI) of 3: Trident, Alaska, and Vestmannaeyjar, Heimaey, south of Iceland. A detailed error analysis of the uncertainties in each of the variables involved in the processing chain was conducted. Relative errors for the uncorrected sAEP532 were 54?% for Fairbanks and 44?% Lexington. For the corrected sAEP532 the errors were 61?% and 64?%, respectively. The analysis of the uncertainties identified variables that with additional data recovery and reprocessing could reduce these relative error levels. Data described in this work are available at https://doi.org/10.1594/PANGAEA.922105 (Antuña-Marrero et al., 2020a).},

keywords = {aerosol, LIDAR},

pubstate = {published},

tppubtype = {article}

}

@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 = {Aerosol Properties, LIDAR, SLOPE, sun photometry},

pubstate = {published},

tppubtype = {article}

}

@article{Barja2021,

title = {Surface shortwave cloud radiative effect of Cumulus (Cu) and Stratocumulus-Cumulus (Sc-Cu) cloud types in the Caribbean area (Camagüey Cuba, 2010-2016)},

author = {B. Barja and J. Rosas and V.E. Cachorro and C. Toledano and J.C. Antuña-Marrero and R. Estevan and A.M. de Frutos},

doi = {10.20937/ATM.52858},

year  = {2021},

date = {2021-06-02},

urldate = {2021-06-02},

journal = {Atmósfera},

volume = {36 (1)},

pages = {41-56},

abstract = {The effects of cumulus (Cu) clouds and the combination of stratocumulus-cumulus (Sc-Cu) clouds on solar radiation at the Earth’s surface were evaluated at Camagüey, Cuba, during a 6-yr period (from June 2010 to May 2016). Two methods to calculate the cloud radiative effect (CRE) were employed. The first method (CREm) uses solar irradiances in cloudy conditions from actinometric observations, where cloud informa-tion was also reported by visual observation. In the second method (CRE0) surface solar irradiances were estimated for both cloudy and clear sky conditions using a 1-D radiative transfer model, and cloud optical depth (COD) retrieved from an AERONET sun-photometer as the main input. A temporal correspondence criterion between COD retrievals and actinometric observations was performed in order to classify the COD of each cloud type. After the application of this criterion, the COD belonging to the optically thin clouds was removed. Finally, 255 and 732 COD observations for Cu and Sc-Cu, respectively, were found. Results show a statistically significant difference at the 95% confidence level between CRE calculated for Sc-Cu and Cu, using both methods. Mean values of CREm and CRE0 for Cu (Sc-Cu) were ?442 (?390) and ?460(?417) Wm–2, respectively. CRE0 shows a linear relation with ln(COD), with stronger correlation at a lower solar zenith angle. The shortwave cloud effect efficiency (CEE) for the two cloud types sharply decreases with the increase of the COD value up to 20. For larger COD, the CEE is less sensitive to the increase of COD.},

keywords = {AERONET, cloud effects on solar radiation (CRE) at surface, cloud radiative effect, radiative transfer simulations},

pubstate = {published},

tppubtype = {article}

}

@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 = {Radiative transfer, sky camera, sky radiance},

pubstate = {published},

tppubtype = {article}

}

@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 = {atmospheric aerosols, ICP-MS, Mining exploitation, SEM-EDX},

pubstate = {published},

tppubtype = {article}

}

@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 = {aerosol inversion, Ceilometer data pre-processing, Microwave radiometry, Vaisala ceilometer},

pubstate = {published},

tppubtype = {article}

}

@article{García2021,

title = {Water Vapor Retrievals from Spectral Direct Irradiance Measured with an EKO MS-711 Spectroradiometer—Intercomparison with Other Techniques},

author = {Rosa Delia García and Emilio Cuevas and Victoria Eugenia Cachorro and Omaira E. García and África Barreto and A. Fernando Almansa and Pedro M. Romero-Campos and Ramón Ramos and Mário Pó and Kees Hoogendijk and Jochen Gross},

url = {https://www.mdpi.com/2072-4292/13/3/350},

doi = {10.3390/rs13030350},

issn = {2072-4292},

year  = {2021},

date = {2021-01-20},

urldate = {2021-01-01},

journal = {Remote Sensing},

volume = {13},

number = {3},

abstract = {Precipitable water vapor retrievals are of major importance for assessing and understanding atmospheric radiative balance and solar radiation resources. On that basis, this study presents the first PWV values measured with a novel EKO MS-711 grating spectroradiometer from direct normal irradiance in the spectral range between 930 and 960 nm at the Izaña Observatory (IZO, Spain) between April and December 2019. The expanded uncertainty of PWV (UPWV) was theoretically evaluated using the Monte-Carlo method, obtaining an averaged value of 0.37 ± 0.11 mm. The estimated uncertainty presents a clear dependence on PWV. For PWV ≤ 5 mm (62% of the data), the mean UPWV is 0.31 ± 0.07 mm, while for PWV > 5 mm (38% of the data) is 0.47 ± 0.08 mm. In addition, the EKO PWV retrievals were comprehensively compared against the PWV measurements from several reference techniques available at IZO, including meteorological radiosondes, Global Navigation Satellite System (GNSS), CIMEL-AERONET sun photometer and Fourier Transform Infrared spectrometry (FTIR). The EKO PWV values closely align with the above mentioned different techniques, providing a mean bias and standard deviation of −0.30 ± 0.89 mm, 0.02 ± 0.68 mm, −0.57 ± 0.68 mm, and 0.33 ± 0.59 mm, with respect to the RS92, GNSS, FTIR and CIMEL-AERONET, respectively. According to the theoretical analysis, MB decreases when comparing values for PWV > 5 mm, leading to a PWV MB between −0.45 mm (EKO vs. FTIR), and 0.11 mm (EKO vs. CIMEL-AERONET). These results confirm that the EKO MS-711 spectroradiometer is precise enough to provide reliable PWV data on a routine basis and, as a result, can complement existing ground-based PWV observations. The implementation of PWV measurements in a spectroradiometer increases the capabilities of these types of instruments to simultaneously obtain key parameters used in certain applications such as monitoring solar power plants performance.},

keywords = {EKO MS-711 spectroradiometer, Monte-Carlo method, spectral direct irradiance, Water vapor},

pubstate = {published},

tppubtype = {article}

}

@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 = {climatology, cloud cover, cuba, diffuse, direct radiation, insolation, Solar radiation},

pubstate = {published},

tppubtype = {article}

}