Effect of cloudiness on solar global, solar diffuse and terrestrial downward radiation at Badajoz (Southwestern Spain)

摘要

Among all the components participating in the Earth radiation balance, clouds exhibit a largeuncertainty in their characterization and quantification, partially due to their complex interactionwith radiation. Although they play a key role attenuating and controlling the solar radiation andabsorbing, scattering and emitting infrared radiation, their description is still very poor and moredetailed studies are demanded. In order to contribute to that aim, simultaneous measurements ofsolar global irradiance, solar diffuse irradiance and downward infrared irradiance on a one‐minutebasis were performed at a radiometric station located in the Campus of the University ofExtremadura in Badajoz (Spain). In this study the information provided by solar irradiance and itspartitioning direct‐to‐diffuse, and by downward infrared irradiance is compared for someparticularly interesting cases of study: cloud‐free, partially cloudy and overcast. It is noted thatinfrared radiation does not exhibit the variability shown by the global solar radiation and directdiffusepartition in the different conditions analysed. The results emphasize the joint use ofmeasurements of solar and infrared radiation which positively contribute to achieve a thoroughdescription of the cloudiness field.