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

Saver-net uv-total solar irradiance monitoring network in Argentina

Resumen: El monitoreo simultáneo de la radiación solar localizada en diferentes rangos espectrales de banda ancha tiene varias ventajas importantes sobre el monitoreo aislado, tanto para la investigación básica como aplicada. Su integración en una red bajo protocolos estandarizados tiene a su vez valiosos beneficios, incluida la posibilidad de caracterizar geográficamente los niveles de radiación solar en grandes regiones. Recientemente, se ha desplegado en Argentina una red integrada de monitoreo de irradiancia solar UV-Total en 8 estaciones con nuevos instrumentos, sitios de medición y protocolos en el marco del proyecto Saver-Net (Japón, Argentina y Chile) llevado a cabo durante el período 2013- 2018. La red es administrada por el Servicio Meteorológico Nacional (SMN) de Argentina y el Instituto de Investigaciones Científicas y Técnicas para la Defensa (CITEDEF- UNIDEF). En este trabajo se describe la estructura y capacidad de la red y varios logros iniciales de la red argentina de monitoreo de irradiancia solar UV-Total con el objetivo de dar a conocer a la comunidad científica y poner a disposición estas bases de datos para su amplio uso en la investigación básica y aplicada. Además, se presenta la caracterización de los sitios donde se encuentra cada nodo de monitoreo de la red. Se observan valores extremos por encima de 1000 Wm−2 para la irradiancia solar Total, 60 Wm−2 para la irradiancia solar UVA e índices UV por encima de 9, aún en los sitios ubicados de la red Saver-Net ubicados más al sur, con su consecuente significancia en aplicaciones prácticas como la generación de energía solar e implicancias en la salud de las personas como el riesgo de contracción de eritema.Abstract: Simultaneous localized solar radiation monitoring in different broadband spectral ranges has several important advantages over isolated measurements for both basic and applied research. Its integration into a network under standardized protocols has, in turn, worthy benefits including the possibility to characterize geographically the solar radiation levels in large regions. Recently, an integrated UV-Total solar irradiance monitoring network has been deployed in Argentina in 8 stations with new instruments, measurement sites, and protocols into the frame of the Saver-Net project (Japan, Argentina, and Chile) carried out during the period 2013-2018. The network is managed by the Argentine Servicio Meteorol´ogico Nacional (SMN) and Instituto de Investigaciones Cient´ıficas y T´ecnicas para la Defensa (CITEDEFUNIDEF). In this paper, the structure, capability and several initial achievements of the Argentine UV-Total solar irradiance monitoring network are described with the aim to make these databases available to the scientific community for their broad use in basic and applied research. In addition, the irradiance characterization at each monitoring node of the network is presented. Extreme values over 1000 Wm−2 of Total solar irradiance, 60 Wm−2 of UVA solar irradiance and UV Index of 9 are registered even in the southernmost stations, with their consequent signification for the practical applications of the solar energy and health implications such as the risk to cause erythema