Sky blue is an ideal hue to help create an inviting space where you can unwind after an exhausting day. This versatile hue works well with numerous hues for an unpretentious yet modern aesthetic.
Light traveling through Earth’s atmosphere comes into contact with gas molecules that scatter shorter wavelengths of blue and violet light more than red light waves; this phenomenon is known as Rayleigh scattering.
Why is the sky blue?
The sky’s characteristic color comes from its surrounding air molecules – mostly nitrogen and oxygen – scattering incoming sunlight towards shorter blue and violet wavelengths of visible light spectrum, giving the sky its distinctive blue hue. This process, known as Rayleigh scattering, gives rise to this hue that defines it so strongly.
Red and orange sunlight wavelengths don’t get scattered by our atmosphere as much, thus accounting for less of the light reflected back at us – explaining why the sky appears darker nearer the horizon while lighter overhead.
At night we see more blue sky than during the day: when dusk approaches and dawn approaches, the sun moves lower on the horizon, meaning its rays must travel a longer path through our atmosphere before reaching our eyes – this exposes more nitrogen and oxygen molecules, which have the tendency to scatter blue light more strongly than other colors of light.
Blue wavelengths of visible light spectrum are more readily absorbed by water than red or orange wavelengths, which explains why we perceive ocean and cloud waters to be bluer in hue. If these wavelengths were not being absorbed, we’d see black water instead!
Tyndall and Rayleigh hypothesized that the sky’s blue hue was caused by small particles of dust or droplets of water vapour in the atmosphere; even today some incorrectly attribute this explanation. Later it was realized that if this were true there would be more variation of sky color depending on humidity or haze conditions than observed, so molecules of oxygen and nitrogen must play their part.
Remember that all gases act as Rayleigh scatterers, so even without dust or aerosol the sky would still appear blue. But dust or aerosol often add to this effect by absorbing some of the scattered light and leaving behind blue-light wavelengths.
Why is the sky whiter near the horizon?
On clear days, the sky can be an exquisite shade of blue that many of us have often questioned why. The answer lies within physics; sunlight passing through Earth’s atmosphere scatters through gas molecules much more strongly in certain wavelengths (particularly blue end of spectrum light) due to Mie Scattering than other colors; this phenomenon is called Mie Scattering.
As light travels from its source to our eyes, its colors blend to form white. Since blue wavelengths scatter more easily than other frequencies, they result in the sky appearing bluer.
However, this only tells part of the tale – other factors such as water vapor, dust particles, ozone levels, chemical pollutants, eye response and cloud coverage also play a part.
From a spot near the horizon, light must travel through more of the atmosphere than when directly overhead; therefore, more gas molecules and Mie scattering occur and therefore, its color becomes paler or even whiter nearer the horizon.
Another factor is the tendency for certain gases in our atmosphere to absorb wavelengths at the blue end of the spectrum, thus decreasing how much blue light reaches our eyes and darkening the sky nearer its horizon.
Additionally, our atmosphere contains more pollutants, ozone and smoke in lower regions than higher regions, leading to darker skies nearer the horizon. Additionally, this also explains why sunrise and sunset often reveal reddish hues due to longer wavelengths of red and orange light that reach our eyes more readily; their combined light produces what humans perceive as white light.
Why is the sky bluer the farther away from the Sun you look?
As sunlight passes through our atmosphere, its light rays become scattered by airborne atoms and particulates. Shorter blue wavelengths scatter more efficiently than longer red wavelengths, explaining why our sky appears bluer as distance increases from the sun. Humidity levels determine its hue but regardless of this factor; distance always results in darker skies.
One common belief about tropical countries’ skies is that they appear less blue. However, this is simply untrue – as the equator’s thinner atmosphere allows more direct Sunrays through, leading them to appear purer due to less attenuation by atmosphere.
Temperature-zone nations tend to have more dense atmospheres than high latitude countries, contributing to their deeper blue skies. Furthermore, more nitrogen and oxygen particles tend to be in the atmosphere than at higher latitudes – making the sky appear bluer overall.
At the same time, as altitude increases, atmosphere attenuates light more effectively – leading to bluer skies on mountaintops even though they share equal altitudes.
At sunrise or sunset, the colors of the sky can become particularly striking. Light must travel through thick atmospheric layers that scatter blue parts more efficiently than reddish portions; as a result, the skies often appear reddish-hued at these times – you can witness this phenomena yourself from an airplane during sunrise/sunset flights with Blue Origin’s suborbital flights; it’s truly captivating, reminding us why outer space skies tend to appear bluer!
Why is the sky bluer at higher elevations?
As sunlight enters our atmosphere it encounters gas molecules and tiny particles which absorb some of its light before scattering it further afield. This scattering effect is most visible for shorter wavelengths (blue and violet), with their shorter wavelength compared to longer ones such as red and orange; more so for blue wavelengths which tend to get scattered than others and ultimately why our sky appears bluer.
As you look further and further above the horizon, the sky becomes bluer as more atmosphere gets in its way of blue light reaching you directly; other colors don’t have to travel quite so far before reaching you directly.
As you travel higher up in elevation, the sky becomes less blue as there is less and less atmospheric gas present. Once above the stratosphere (such as in a jet plane or space travel) there is very little air available and therefore very little light scatters off surfaces; so, it appears quite dark.
The color of the sky varies based on where and what time of day it is, such as where you are or the season. For instance, summer skies tend to be brighter and more blue because more water vapor fills the atmosphere than usual and scatters light making it appear even bluer.
Winter skies tend to be less vibrant due to lower water vapor levels and colder temperatures, leading to thicker and denser air which allows more blue light to be absorbed and thus reduced scattering, producing darker skies that appear less blue overall. Dust particles in the air may also contribute to making its color seem milky white.