@misc{10481/90346,
year = {2023},
url = {https://hdl.handle.net/10481/90346},
abstract = {This study is the last of a series of three research papers analysing the solar radiation and its interaction with the
atmospheric components spanning an eleven-year period (2008–2018) at a mid-latitude urban site in the
Mediterranean basin. During the previous works a detailed characterization of the photosynthetically active
radiation (PAR; 400–700 nm), as well as analysis the aerosol and clouds effects on PAR was carried out. This
research work addresses an analysis of solar radiation on the total solar irradiance spectrum (TSI; 280–3000 nm)
in terms of the effects of different atmospheric conditions on it, considered by the clearness index and the cloud
cover, bringing very valuable findings from the long-term comparative analysis of radiative effects of clouds on
TSI and PAR wavelength ranges. The average values in the entire period of the study for the global solar radiation
in the total solar irradiance (TSIGlobal) found to be 450 ± 100 Wm-2 and 530 ± 110 Wm-2 under all and clearsky
conditions, respectively. Meanwhile, the average values for the diffuse component (TSIDiffuse) are 141 ± 21
Wm-2 and 130 ± 21 Wm-2 (all and clear skies, respectively), with a relatively low interannual variation up to
11% for both global and diffuse TSI, as well as for both sky conditions. Analysis on the total cloud cover (TCC)
shows that the clearness index is not a good parameter to discriminate between all and clear sky conditions, since
there is a marked overlap in the ranges of the kt values for the different categories of TCC. Additionally, the cloud
radiative forcing (CRF) are computed as the difference in solar radiation measured under all and clear sky
conditions. A high seasonal variability is found for CRF, where CRFTSI,Global ranges between -37.6 Wm-2 and
-137.4 Wm-2, while CRFTSI,Diffuse from 4.4 Wm-2 to 22.6 Wm-2. The positive sign implies increase in solar
radiation at the surface, while the negative one implies the opposite, i.e., less availability of solar radiation on the
surface. Finally, the analysis of the annual evolution of CRF reveals a downward trend on CRFTSI and CRFPAR, for
both global and diffuse This relevant finding implies that clouds are exerting less cooling effects over time at this
Mediterranean site.},
organization = {Spanish Ministry of Economy and
Competitiveness through projects CGL2017-90884-REDT, PID2020-120015RB-I00, ID2020-117825GB-C21, PID2020-117825GB-C22 and
PID2021-128008OB-I00},
organization = {Andalusia Regional Government, University
of Granada and FEDER funds through project B-RNM-524-UGR20, P20-00136 and P18-RT-3820},
organization = {Scientific Units of Excellence Program (grant no. UCEPP2017-02)},
organization = {Open Access funding provided
by University of Helsinki},
publisher = {Elsevier},
keywords = {Cloud radiative forcing},
keywords = {Direct/diffuse partitioning},
keywords = {Photosynthetically active radiation},
title = {Analysis of the solar radiation/atmosphere interaction at a Mediterranean site: The role of clouds},
doi = {10.1016/j.atmosres.2023.107072},
author = {Lozano, Ismael L. and Alados, Inmaculada and Foyo Moreno, Inmaculada},
}