Irradiancia e irradiación UV-A a partir de medidas con radiómetros a 380 nm para aplicaciones ambientales de la energía solar

El correcto dimensionamiento de plantas de tratamiento por fotocatálisis solar requiere del conocimiento del recurso solar UV (280-400 nm) a nivel de la superficie terrestre. El UV-B (280-315nm), sólo constituye el 10% del total y se transmite sólo el 55% al ingresar al reactor, mientras que el UV-A(315-400 nm) se transmite en un 89%. En este trabajo se presenta y evalúa un método para calcular la irradiancia e irradiación UV-A a partir de mediciones a 380nm por medio del uso de un factor de escala dependiente del ángulo cenital solar. Los errores en la irradiancia calculada van del 18% a θ = 90º hasta 4% a θ =10º. El error en la irradiación UV-A calculada es del 10.2% para las integrales diarias. Estos errores están dentro del rango de incertidumbre aceptable para la mayoría de los sistemas fotocatalíticos solares y pueden ser usadas para los estudios de factibilidad.Proper dimensioning of plants for photocatalytic treatment of wastewaters require the knowledge of the UV solar resource availability. In this work, a method to calculate UV-A irradiance and irradiation from measurements at 380 nm by means of a scale factor dependant only on the solar zenith angle is proposed and evaluated. Errors in the calculated UV-A irradiance range from 18% at θ = 90º to 4% at θ =10º. Errors in the calculated UV-A irradiation are less than 11% for daily integrals. These errors are well within the range of acceptable uncertainty for most photocatalytic systems dimensioning and the procedure may be use for other applications as well. The next step is the establishment of relationships between UV-A and global solar radiation, and a map of the solar UV-A resource for Argentina.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

Irradiancia e irradiación UV-A a partir de medidas con radiómetros a 380 nm para aplicaciones ambientales de la energía solar

El correcto dimensionamiento de plantas de tratamiento por fotocatálisis solar requiere del conocimiento del recurso solar UV (280-400 nm) a nivel de la superficie terrestre. El UV-B (280-315nm), sólo constituye el 10% del total y se transmite sólo el 55% al ingresar al reactor, mientras que el UV-A(315-400 nm) se transmite en un 89%. En este trabajo se presenta y evalúa un método para calcular la irradiancia e irradiación UV-A a partir de mediciones a 380nm por medio del uso de un factor de escala dependiente del ángulo cenital solar. Los errores en la irradiancia calculada van del 18% a θ = 90º hasta 4% a θ =10º. El error en la irradiación UV-A calculada es del 10.2% para las integrales diarias. Estos errores están dentro del rango de incertidumbre aceptable para la mayoría de los sistemas fotocatalíticos solares y pueden ser usadas para los estudios de factibilidad.Proper dimensioning of plants for photocatalytic treatment of wastewaters require the knowledge of the UV solar resource availability. In this work, a method to calculate UV-A irradiance and irradiation from measurements at 380 nm by means of a scale factor dependant only on the solar zenith angle is proposed and evaluated. Errors in the calculated UV-A irradiance range from 18% at θ = 90º to 4% at θ =10º. Errors in the calculated UV-A irradiation are less than 11% for daily integrals. These errors are well within the range of acceptable uncertainty for most photocatalytic systems dimensioning and the procedure may be use for other applications as well. The next step is the establishment of relationships between UV-A and global solar radiation, and a map of the solar UV-A resource for Argentina.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

Irradiancia e irradiación UV-A a partir de medidas con radiómetros a 380 nm para aplicaciones ambientales de la energía solar

El correcto dimensionamiento de plantas de tratamiento por fotocatálisis solar requiere del conocimiento del recurso solar UV (280-400 nm) a nivel de la superficie terrestre. El UV-B (280-315nm), sólo constituye el 10% del total y se transmite sólo el 55% al ingresar al reactor, mientras que el UV-A(315-400 nm) se transmite en un 89%. En este trabajo se presenta y evalúa un método para calcular la irradiancia e irradiación UV-A a partir de mediciones a 380nm por medio del uso de un factor de escala dependiente del ángulo cenital solar. Los errores en la irradiancia calculada van del 18% a θ = 90º hasta 4% a θ =10º. El error en la irradiación UV-A calculada es del 10.2% para las integrales diarias. Estos errores están dentro del rango de incertidumbre aceptable para la mayoría de los sistemas fotocatalíticos solares y pueden ser usadas para los estudios de factibilidad.Proper dimensioning of plants for photocatalytic treatment of wastewaters require the knowledge of the UV solar resource availability. In this work, a method to calculate UV-A irradiance and irradiation from measurements at 380 nm by means of a scale factor dependant only on the solar zenith angle is proposed and evaluated. Errors in the calculated UV-A irradiance range from 18% at θ = 90º to 4% at θ =10º. Errors in the calculated UV-A irradiation are less than 11% for daily integrals. These errors are well within the range of acceptable uncertainty for most photocatalytic systems dimensioning and the procedure may be use for other applications as well. The next step is the establishment of relationships between UV-A and global solar radiation, and a map of the solar UV-A resource for Argentina.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

Spectrum reconstructions of global solar UV irradiance using narrow band radiometer measurements

La medición de la región ultravioleta (UV) de la radiación solar ha sido motivo de sumo interés desde la aparición del fenómeno de adelgazamiento global de la capa de ozono. Diferentes propuestas tecnológicas fueron utilizadas para tal fin, desde radiómetros de banda ancha, hasta los costosos espectrorradiómetros. Los radiómetros de ancho de banda moderado (típicamente 10 nm) con canales centrados en las regiones UVA y UVB, son una solución intermedia entre las dos anteriores y están ampliamente distribuidos. En este trabajo se describe un método para realizar la reconstrucción del espectro UV entre 290 y 400 nm a partir de las mediciones de un instrumento de este tipo y de la utilización conjunta de un modelo de transferencia radiativa. A partir de la reconstrucción del espectro solar UV en superficie con una resolución de 1 nm es posible monitorear la estabilidad de los distintos canales de los radiómetros a lo largo del tiempo, y también calcular diferentes subproductos, como la irradiancia eritémica y el índice UV. Se presentan resultados para instrumentos GUV de Biospherical Instruments Inc., instalados en el país. También se comparan los valores de la radiación biológicamente efectiva (irradiancia eritémica) calculada por este método con la medida directa de diferentes biómetros de la estación de sensado remoto que el CEILAP tiene instalado en el sitio SOLAR en la ciudad patagónica de Rio Gallegos.The measurement of ultraviolet (UV) solar radiation has been a subject of great interest since the emergence of the global depletion of the ozone layer phenomenon. Different technological proposals were used to this purpose, from broadband radiometers to expensive spectroradiometers. Moderate ubandwidth uradiometers u(typically u10 unm) uwith uchannels uon uregions uUVA uand uUVB, uare ua intermediate usolution ubetween uthe utwo previous instruments, and they are widely distributed. This paper describes a method to carry out the reconstruction of the UV spectrum between 290 and 400 nm from measurements of this kind of instrument and the joint use of a radiative transfer model. From the reconstruction of UV solar spectrum in surface with a resolution of 1 nm it is possible to monitor the stability of the various channels of the radiometers over time, and also to calculate different subproducts, as erythemical irradiance and UV index. The results for GUV instruments from Biospherical Instruments Inc. installed in the country are presented. The values of biologically effective radiation (erythemical irradiance) calculated by this method with direct measurement from different biometers CEILAP has installed in the SOLAR site in the Patagonian city of Rio Gallegos, are also compared.Centro de Investigaciones Óptica

Stratospheric ozone profiles monitoring with DIAL technique in Río Gallegos

El adelgazamiento de la capa de ozono sobre el polo sur de nuestro planeta es un fenómeno estacional que desde la década de los ‘80 se desarrolla cada año durante la primavera. El mismo tiene su máxima expresión sobre la región Antártica, en donde el área de la región con adelgazamiento ha llegado a tener 30 millones de kilómetros cuadrados aproximadamente, alcanzando así en sus bordes la parte sur de nuestro país. Durante la primavera austral de 2005, en la ciudad de Río Gallegos, se desarrolló la primera campaña de mediciones intensivas de parámetros atmosféricos denominada SOLAR (Stratospheric Ozone Lidar of Argentina) realizada por la División Lidar del CEILAP. En la misma se midieron perfiles de ozono utilizando la técnica lidar de absorción diferencial (DIAL), pudiéndose registrar un total de 29 mediciones durante el periodo agosto – noviembre de 2005, cinco de ellas coincidentes con reducción significativa del contenido total de ozono. En el presente trabajo, se presenta un análisis cualitativo de las mismas que permite visualizar las zonas de la estratosfera que más fueron afectadas por el paso del vórtice polar. La utilización de un sistema de coordenadas cuasi-conservativo (latitud equivalente, nivel isentrópico) permitió realizar la selección de los días dentro de esta campaña de medición que estuvieron afectados por el paso del vórtice polar Antártico que contiene al agujero de ozono.The thinning of the ozone layer over the South Pole of our planet is a seasonal phenomenon that from the decade of the 80’s is developed every year during spring time. The same one has its Maxima expression on the Antarctica region, in where the area of the region with ozone depletion has gotten to have 30 million of square kilometers approximately, thus reaching in its edges the South part of our country. During the austral spring of 2005, in the Río Gallegos city, the first campaign of intensive measurements of atmospheric parameters was developed. The same is named SOLAR (Stratospheric Ozone Lidar of Argentina) and is held by the Lidar Division of the CEILAP. We measured ozone profiles using the differential absorption lidar technique (DIAL), being able to register a total of 29 measurements during the period August - November of 2005, five of them coincident with significant reduction of the total ozone content. In the present work, a qualitative analysis of the same ones appears that allows to visualize the zones of the stratosphere which they were more affected by the passage of the polar vortex. The use of a quasi-conservative system of coordinates (equivalent latitude, isentropic level) allowed to make the selection of the days within this campaign of measurement that were affected by the passage of the Antarctic polar vortex that contains to the ozone hole.Fil: Wolfram, Elian Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Científicas y Técnicas para la Defensa. Centro de Investigación en Láseres y Aplicaciones; ArgentinaFil: Salvador, Jacobo Omar. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Pallotta, Juan Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Científicas y Técnicas para la Defensa. Centro de Investigación en Láseres y Aplicaciones; ArgentinaFil: D´Elia, R.. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Científicas y Técnicas para la Defensa. Centro de Investigación en Láseres y Aplicaciones; ArgentinaFil: Pazmiño, A.. Service D’Aeronomie; ArgentinaFil: Godin Beeckmann, S.. Service D’Aeronomie; ArgentinaFil: Quel, Eduardo Jaime. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Científicas y Técnicas para la Defensa. Centro de Investigación en Láseres y Aplicaciones; Argentin

Changes in the surface irradiance during the total solar eclipse 2020 in Valcheta, Argentina

On December 14, 2020, southern South America experienced a total solar eclipse close to the solar noon. The path of totality, about 90 km wide, extended over the continental region from the Chilean west coast to the Argentine east coast, passing through the provinces of Neuquén, Río Negro and the extreme south of Buenos Aires. In order to study the effects on the atmosphere produced by the total eclipse, the Servicio Meteorológico Nacional Argentino (SMN) and Instituto de Investigaciones Científicas y Técnicas para la Defensa (CITEDEF) carried out a surface radiometric monitoring campaign in Valcheta (40.69°S; 66.15°W), Río Negro, Argentina. In this work, we explore the global surface solar irradiance on a horizontal plane (GHI) with the main objective of quantifying the changes in this parameter for cloudy and clear sky atmospheric conditions, combining ground-based measurements and modeling. A solar limb-darkening function was successfully implemented in the calculation of the irradiance at the top of the atmosphere (TOA) during the eclipse. We estimated a significant GHI attenuation of 41 % between the first (C1) and last (C4) contacts of eclipse compared to similar atmospheric conditions without the total eclipse, which represent a daily reduction of 12 %. In terms of irradiation, a reduction of 3360.1 KJ/m2 was calculated

How Certain are We of the Uncertainties in Recent Ozone Profile Trend Assessments of Merged Limbo Ccultation Records? Challenges and Possible Ways Forward

Most recent assessments of long-term changes in the vertical distribution of ozone (by e.g. WMO and SI2N) rely on data sets that integrate observations by multiple instruments. Several merged satellite ozone profile records have been developed over the past few years; each considers a particular set of instruments and adopts a particular merging strategy. Their intercomparison by Tummon et al. revealed that the current merging schemes are not sufficiently refined to correct for all major differences between the limb/occultation records. This shortcoming introduces uncertainties that need to be known to obtain a sound interpretation of the different satellite-based trend studies. In practice however, producing realistic uncertainty estimates is an intricate task which depends on a sufficiently detailed understanding of the characteristics of each contributing data record and on the subsequent interplay and propagation of these through the merging scheme. Our presentation discusses these challenges in the context of limb/occultation ozone profile records, but they are equally relevant for other instruments and atmospheric measurements. We start by showing how the NDACC and GAW-affiliated ground-based networks of ozonesonde and lidar instruments allowed us to characterize fourteen limb/occultation ozone profile records, together providing a global view over the last three decades. Our prime focus will be on techniques to estimate long-term drift since our results suggest this is the main driver of the major trend differences between the merged data sets. The single-instrument drift estimates are then used for a tentative estimate of the systematic uncertainty in the profile trends from merged data records. We conclude by reflecting on possible further steps needed to improve the merging algorithms and to obtain a better characterization of the uncertainties involved

Extreme ultraviolet index due to broken clouds at a midlatitude site, Granada (southeastern Spain)

Cloud cover usually attenuates the ultraviolet (UV) solar radiation but, under certain sky conditions, the clouds may produce an enhancement effect increasing the UV levels at surface. The main objective of this paper is to analyze an extreme UV enhancement episode recorded on 16 June 2009 at Granada (southeastern Spain). This phenomenon was characterized by a quick and intense increase in surface UV radiation under broken cloud fields (5-7oktas) in which the Sun was surrounded by cumulus clouds (confirmed with sky images). Thus, the UV index (UVI) showed an enhancement of a factor 4 in the course of only 30min around midday, varying from 2.6 to 10.4 (higher than the corresponding clear-sky UVI value). Additionally, the UVI presented values higher than 10 (extreme erythemal risk) for about 20min running, with a maximum value around 11.5. The use of an empirical model and the total ozone column (TOC) derived from the Global Ozone Monitoring Experiment (GOME) for the period 1995-2011 showed that the value of UVI~11.5 is substantially larger than the highest index that could origin the natural TOC variations over Granada. Finally, the UV erythemal dose accumulated during the period of 20min with the extreme UVI values under broken cloud fields was 350J/m 2 which surpass the energy required to produce sunburn of the most human skin types.Fil: Antón, M.. Universidad de Granada; EspañaFil: Piedehierro, A. A.. Universidad de Extremadura; EspañaFil: Alados Arboledas, L.. Universidad de Granada; EspañaFil: Wolfram, Elian Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; Argentina. Ministerio de Defensa. Armada Argentina. Servicio de Hidrografía Naval; ArgentinaFil: Olmo, F. J.. Universidad de Granada; Españ

SOLAR campaign: stratospheric ozone lidar of Argentina

International audienceAs part of environmental studies of the southern atmosphere, the CEILAP Lidar Division in collaboration with the Service d'Aeronomie has developed a mobile differential absorption lidar capable of making precise and accurate measurements of the stratospheric ozone. The XeCl excimer laser emission at 308 nm is used as absorbed line in the DIAL technique and an Nd-YAG laser 355 nm third harmonic is employed as a reference wavelength. Six detected channels are used for stratospheric ozone retrieval, four of them in the high and low energy of the elastically backscattered signal of the emitted wavelengths and two corresponding to the first Stokes nitrogen Raman of the emitted wavelengths. Tropospheric Water Vapor profiles using Raman channels and Aerosol Backscatter profiles are also obtained. In this paper we present a detailed description of the instrument, a discussion of data analysis and the results of the first lidar-satellite inter-comparison of stratospheric ozone profiles measured with this instrument. We also present a description of the SOLAR campaign that will be held in the 2005 southern winter-spring period in Rio Gallegos (51° 55'S, 69° 14'W) with the objective of studying the ozone layer when the polar vortex crosses over the continental part of Argentina. This campaign will be supported by JICA (Japan International Cooperation Agency)