Analísis de las tendencias de la radiación solar en la Península Ibérica desde finales del siglo XIX

Abstract

This thesis analyzes the temporal variability of solar radiation and cloudiness in the Iberian Peninsula from the late 19th century to the present day. To achieve this, data on sunshine and cloudiness collected over more than 100 years at three key observatories are employed. Initially, data from internal observatory publications are digitized and retrieved, thereby complementing official meteorological records. The identified radiative trends reveal four significant periods. In Lisbon and Coimbra, an "early dimming" is observed until the 1910s, followed by an "early brightening" in Badajoz until the mid-20th century. Subsequently, a new "dimming" is recorded until the 1980s, succeeded by a "brightening" until the early 21st century. The connection between cloudiness trends and variations in solar radiation throughout these periods is also highlighted. Additionally, the analysis of clear skies unveils the decisive influence of aerosols on long-term solar radiation. Furthermore, the comparison between satellite-derived time series of solar radiation and measurements from pyranometers between 1985 and 2015 underscores notable discrepancies in trends. These discrepancies are possibly attributed to the lack of consideration of changes in aerosol loading in satellite models. Overall, this study significantly contributes to understanding regional and global climate variability over decades, providing valuable insights into radiative patterns and their relationship with long-term atmospheric phenomena.