Answer · confidence: partial
Why does smoke glow orange at sunset but leave noon sky pale, not blue?
Research question: Why does a smoke plume that glows orange at sunset still leave the midday sky looking washed out instead of deep blue?
The records show that air molecules scatter light with a strong wavelength dependence, favoring blue and producing the deep blue sky 5. Smoke particles scatter with a much weaker wavelength dependence, so they add more evenly colored light that dilutes the blue 7. As haze thickens, the sky's B/R ratio falls toward 1.0 and the sky shifts from blue to gray 8. The provided facts do not directly explain the orange glow at sunset, so that part of the question is only partly answered 57. The newest fact provided dates from 2022, roughly four years before October 2026 34.
Checked 2026-10-21. Only documented and supported facts are used.
Dig deeper on this questionSources
[1] supported
When an electromagnetic wave meets an electron bound to a molecule, the wave's electric field accelerates that electron.
"When an electromagnetic field encounters an electron bound to a molecule, the electron is accelerated by the electric field of the wave."Electromagnetic Scattering: The Mie Solution (2017)
[2] supported
An accelerated electron radiates electromagnetic energy in all directions to some extent, and this radiation is called scattered radiation.
"An accelerated electron will also radiate electromagnetic energy in the form of waves in all directions (to some extent)—this is known as scattered radiation."Electromagnetic Scattering: The Mie Solution (2017)
[3] documented
Smoke that reaches the stratosphere stays airborne much longer than smoke in lower layers of the atmosphere.
"Oncethere,smokeaerosolremainedairborneconsiderablylongerthanin"Important role of stratospheric injection height for the distribution and radiative forcing of smoke aerosol from the 2019–2020 Australian wildfires (2022)
[4] supported
Smoke from the Australian fires enhanced atmospheric opacity by spreading across mid and high southern latitudes.
"mid-latitudesintheSouthernHemisphere,enhancingtheatmosphericopacity."Important role of stratospheric injection height for the distribution and radiative forcing of smoke aerosol from the 2019–2020 Australian wildfires (2022)
[5] supported
Air molecules scatter light with a strong wavelength dependence (Rayleigh scattering), which favors blue light and produces the deep blue sky.
"Scattering is given a wavelength (λ) dependence of λ −4 for air molecules (Rayleigh scattering), λ −1 for tropospheric aerosols, and λ +1 for volcanic aerosol particles."Simulating colors of clear and partly cloudy skies (2005)
[6] supported
Rayleigh gave an explanation for the blue color of the sky, as part of his work in optics.
"En el campo de la óptica realizó una serie de trabajos sobre la polarización de la luz, contribuyó a la teoría de la radiación del cuerpo negro y logró dar una explicación del color azul del cielo."Lord Rayleigh
[7] supported
Tropospheric aerosols, such as smoke particles, scatter with a much weaker wavelength dependence than air molecules, so they scatter blue light less preferentially and add more evenly colored light that dilutes the blue.
"λ −1 for tropospheric aerosols"Simulating colors of clear and partly cloudy skies (2005)
[8] documented
As haze thickens, the B/R ratio of the sky falls toward 1.0 and the sky shifts from blue to gray.
"にヘイズが濃くなるとB/R比は1.0に接近し，空は青"Relations between the Sky Hue and Aerosol Scattering (2009)