The night sky has an overall background luminosity, we all know the localize sources of lights like stars, planets right .. , but in addition to the astronomical sources there is an overall uniform luminosity originating from the Earth's own atmosphere. We are not normally aware of this airglow because it is so uniform
Actually, It is the combination of astronomical and airglow sources that allows us to see the silhouette of an object held against the "dark" sky on a clear moonless night.
Difference Between Earth Glow and Aurora
Difference |
AirGlow |
Aurora |
spatial extent |
global |
high latitude |
luminosity |
relatively uniform |
highly structured |
energy source |
solar radiation |
solar wind |
Now that you have understood the difference between these 2 things , let's get into types of Airglow ..
Types of AirGlow
- Dayglow
- Twilightglow
- Nightglow
Dayglow
Dayglow (when entire atmosphere is illuminated by the Sun) is the brightest airglow due to the importance of RESONANT and
FLUORESCENT processes but it is overwhelmed by direct and scattered sunlight…
Twilightglow
Twilightglow (when only the upper atmosphere is illuminated) is the most readily observable airglow
from the ground since the observer is in darkness (and Rayleigh scattering of sunlight by the dense lower
atmosphere is absent) while the airglow region of upper atmosphere is still illuminated...
Nightglow
Nightglow (when entire atmosphere is in darkness) is not as bright as dayglow since
CHEMILUMINESCENCE is the dominant process; however contributes more light than starlight to
the total luminosity of the night sky...
One of my instagram follower suggest to make a stroy series about this topic because many people confuse airglow with auroras , but while learning
about this topic i get to learn many new things like its also divided into parts and main componants creates this natural light beauty..