Light refraction in the earth’s atmosphere I. Inferior mirages: analytic solution of ray paths



Título del documento: Light refraction in the earth’s atmosphere I. Inferior mirages: analytic solution of ray paths
Revista: Revista mexicana de física
Base de datos: PERIÓDICA
Número de sistema: 000460665
ISSN: 0035-001X
Autores: 1
1
1
Instituciones: 1Universidad Católica de La Plata, Facultad de Ciencias Astronómicas y Geofísicas, La Plata, Buenos Aires. Argentina
Año:
Periodo: Jul-Ago
Volumen: 68
Número: 4
País: México
Idioma: Inglés
Tipo de documento: Artículo
Enfoque: Analítico, descriptivo
Resumen en inglés We aim to reach an analytic expression that describes the path of light rays through the Earth’s atmosphere in the particular situation in which an inferior mirage is occurring. To achieve our goal, we assume an exponential refractive index profile close to the ground, as suggested by empirical and theoretical studies on the state of air when an inferior mirage is taking place. We consider a parallel-plane atmosphere and assume that the laws of geometric optics apply. Since Fermat’s principle holds, we solve the Euler’s equation and, from the solution we obtain an analytic expression that describes the ray paths in a plane perpendicular to the ground. Given that we focus on the particular case of inferior mirages, we were able to find a very simple and easy-to-use expression to describe the ray paths, allowing us to extract additional valuable information with minimal computational effort. We take advantage of it to impose a limit to the thickness of the air layer next to the ground where appropriate conditions exist to bend the rays upwards, and produce an inferior mirage
Disciplinas: Física y astronomía
Palabras clave: Astronomía,
Atmósfera planetaria,
Refracción de la luz,
Espejismos inferiores,
Expresión analítica
Keyword: Astronomy,
Planetary atmospheres,
Light refraction,
Inferior mirages,
Analytic expression
Texto completo: Texto completo (Ver HTML) Texto completo (Ver PDF)