Publication list

Peer reviewed articles and book chapters

"And if my poor talents, my little experience of the present and insufficient study of the past, should make the result of my labors defective and of little utility, I shall at least have shown the way to others, who will carry out my views with greater ability, eloquence, and judgment, so that if I do not merit praise, I ought at least not to incur censure."

-- Niccolo Machiavelli, Discourses on Livy, 1531.

· A. Delgado-Bonal, Entropy of radiation: the unseen side of light, Scientific Reports, 7, 1642, (2017) doi:10.1038/s41598-017-01622-6 PDF - .bib

· A. Delgado-Bonal and F. J. Martín-Torres, Human vision is determined based on information theory, Scientific Reports, 6, 36038, (2016) doi:10.1038/srep36038 PDF - .bib

· A. Delgado-Bonal, M.-P Zorzano and F. J. Martín-Torres, Martian Top of the Atmosphere 10-to 420 nm spectral irradiance database and forecast for solar cycle 24, Solar Energy, Vol. 134, pp. 228-325, (2016) doi:10.1016/j.solener.2016.05.004 PDF - .bib

· A. Delgado-Bonal, F. J. Martín-Torres, S. Vázquez-Martín, M.-P. Zorzano, Solar and wind exergy potentials for Mars, Energy, Vol. 102, pp. 550-558, (2016) doi:10.1016/ PDF - .bib

· A. Delgado-Bonal and F. J. Martín-Torres, Solar Cell Temperature on Mars, Solar Energy, Vol. 118, pp. 74-79, (2015) doi:10.1016/j.solener.2015.04.035 PDF - .bib

· A. Delgado-Bonal and F. J. Martín-Torres, Evaluation of the Mars atmospheric chemical entropy production, Entropy, Vol. 17, pp. 5047-5062, (2015) doi:10.3390/e17075047 PDF - .bib

· A. Delgado-Bonal and F. J. Martín-Torres, A Mathematic Approach to Nitrogen Fixation Through Earth History, in: The Early Evolution of the Atmospheres of Terrestrial Planets, Springer, Vol. 35, pp. 23-31, (2013) doi:10.1007/978-1-4614-5191-4_3 PDF - .bib

Recent Papers

Nov 2016

Human vision is determined based on information theory

Scientific Reports

It is commonly accepted that the evolution of the human eye has been driven by the maximum intensity of the radiation emitted by the Sun. However, the interpretation of the surrounding environment is constrained not only by the amount of energy received but also by the information content of the radiation. Information is related to entropy rather than energy. The human brain follows Bayesian statistical inference for the interpretation of visual space. The maximization of information occurs in the process of maximizing the entropy. Here, we show that the photopic and scotopic vision absorption peaks in humans are determined not only by the intensity but also by the entropy of radiation. We suggest that through the course of evolution, the human eye has not adapted only to the maximum intensity or to the maximum information but to the optimal wavelength for obtaining information. On Earth, the optimal wavelengths for photopic and scotopic vision are 555 nm and 508 nm, respectively, as inferred experimentally. These optimal wavelengths are determined by the temperature of the star (in this case, the Sun) and by the atmospheric composition. doi:10.1038/srep36038 PDF - .bib

May 2016

Martian Top of the Atmosphere 10-to 420 nm spectral irradiance database and forecast for solar cycle 24

Solar Energy

Ultraviolet radiation from 10 to 420 nm reaching Mars Top of the Atmosphere (TOA) and surface is important in a wide variety of fields such as space exploration, climate modeling, and spacecraft design, as it has impact in the physics and chemistry of the atmosphere and soil. Despite the existence of databases for UV radiation reaching Earth TOA, based in space-borne instrumentation orbiting our planet, there is no similar information for Mars. Here we present a Mars TOA UV spectral irradiance database for solar cycle 24 (years 2008–2019), containing daily values from 10 to 420 nm. The values in this database have been computed using a model that is fed by the Earth-orbiting Solar Radiation and Climate Experiment (SORCE) data. As the radiation coming from the Sun is not completely isotropic, in order to eliminate the geometrically related features but being able to capture the general characteristics of the solar cycle stage, we provide 3-, 7- and 15-days averaged values at each wavelength. Our database is of interest for atmospheric modeling and spectrally dependent experiments on Mars, the analysis of current and upcoming surface missions (rovers and landers) and orbiters in Mars. Daily values for the TOA UV conditions at the rover Curiosity location, as well as for the NASA Insight mission in 2016, and ESA/Russia ExoMars mission in 2018 are provided. doi:10.1016/ - PDF - .bib

Featured article

May 2017

Entropy of radiation: the unseen side of light

· A. Delgado-Bonal - Scientific Reports

entropy ratio

Despite the fact that 2015 was the international year of light, no mention was made of the fact that radiation contains entropy as well as energy, with different spectral distributions. Whereas the energy function has been vastly studied, the radiation entropy distribution has not been analysed at the same speed. The Mode of the energy distribution is well known -Wien's law- and Planck's law has been analytically integrated recently, but no similar advances have been made for the entropy. This paper focuses on the characterization of the entropy of radiation distribution from an statistical perspective, obtaining a Wien's like law for the Mode and integrating the entropy for the Median and the Mean in polylogarithms, and calculating the Variance, Skewness and Kurtosis of the function. Once these features are known, the increasing importance of radiation entropy analysis is evidenced in three different interdisciplinary applications: defining and determining the second law Photosynthetically Active Radiation (PAR) region efficiency, measuring the entropy production in the Earth's atmosphere, and showing how human vision evolution was driven by the entropy content in radiation.
doi:10.1038/s41598-017-01622-6 PDF - .bib