The sky appears blue during the day because nitrogen and oxygen molecules in the atmosphere scatter sunlight more intensely at short wavelengths, that is, in the blue and violet range.
Our eyes are more sensitive to blue, and part of the violet light is absorbed by the upper layer of the atmosphere, which is why we perceive a bluish hue.
Why does the color change at sunset?
When the Sun is low on the horizon, its light has to travel through a greater amount of atmosphere before reaching our eyes.
During that longer journey, Rayleigh scattering removes almost all of the blue and violet light, allowing longer-wavelength colors such as red, orange and yellow to dominate.
In addition, the presence of particles such as dust, salt or pollutants can intensify these warm tones by also scattering red light.
Factors that influence the variation in color
- Solar angle: the greater the distance the light travels, the more the short wavelengths are removed.
- Atmospheric composition: normal concentrations of gases produce the typical scattering; variations in humidity or pollution alter the intensity of the colors.
- Suspended particles: aerosols and sea spray scatter light less selectively, favoring the diffusion of longer wavelengths and creating redder sunsets.
Me encantó cómo explican la dispersión de Rayleigh de forma clara y sencilla.
¡Qué interesante! Ahora entiendo por qué los atardeceres son tan rojizos y anaranjados.
Excelente artículo, me ayudó a recordar conceptos de física de forma amena.