Spectral Entropy in Atmospheres

Dear Colleague,

After the work of Boltzmann on the thermodynamics of radiation and the development of its famous distribution, Planck introduced the concept of radiation quanta in 1900. Using this new concept, he presented the expression of the spectral entropy associated with each vibrational frequency mode, and formulated the famous law of blackbody radiation. Later, Beretta and Gyftopoulos remarked on the fact that electromagnetic radiation carries both energy and entropy, and that for blackbody radiative transfer between two systems at different temperatures, the rate of entropy transfer is not equal to the ratio of energy transfer rate between the two systems to the temperature of either of the systems. Since the works by Petela in the 1960s, the importance of entropy and exergy of radiation to energy conversion has been considered in many works, and, for example, extensive studies have been published to determine the maximum efficiency of solar energy converters.

In the particular cases of the solar or stellar radiation reaching a planet around them, it interacts with the atmospheric components (gas species, clouds, dust, aerosols, etc.) and the surface of the planet, and the radiation undergoes processes of absorption, scattering and emission. These processes have an impact on the spectral entropy distribution of the radiation reaching the surface and leaving the atmosphere of the planet, and its study can provide information about the composition and physical processes of a planet. Similarly, the spectral distribution of the entropy during the transfer between the layers of the solar and stellar radiation also will provide information about the solar (and other stars’) phenomena in their internal layers.

In this Special Issue, attention is paid to contributions dealing with spectral entropy associated with the emission, transmission, and scattering processes of radiation in the atmospheres of planets, the Sun, and other stars.

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Entropy is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

• spectral entropy
• planetary atmospheres
• stellar atmosphere
• exergy
• Planck function
• reversible processes
• irreversible processes
• radiative transfer
• spectral energy
• scattering, emission, absorption, blackbody