Atmospheric Optical Phenomena Research Paper Afterglow

Cause and occurrence of an airglow
The oxygen line appearing in an airglow has been studied by scientists and spectroscopists for decades. They have come up with two distinct ways of approaching the phenomenon;the electron excitation hypothesis and the photochemical excitation theory (Bates and Chamberlain, 1996).
According to photochemical excitation, radiation in the airglow is basically, the photochemical release of oxygen dissociation energy stored in the lower regions of the thermosphere. It is an established fact that the transition of oxygen from molecular to atomic states occurs at the same level (Khomic,2010).
When energy is deposited in the air, the molecules become excited and as a result, gases like oxygen and nitrogen react to form molecules. The molecules react with other molecules forming ozone. Presence of air vapor, which is characterized emission of hydrogen makes the plasma react with other chemicals in the air. As a result, their collision with x-rays leads to occurrence of an airglow.
Alpenglow
An alpenglow is easily observed when the sun is just below the horizon. Light from the sun lacks a direct path to reach the earth’s surface, so it instead reflects water, snow or ice particles. In this scenario, a normal sunrise or sunset is separated from the alpenglow. In the case where there are no mountains, the aerosols of the sky are illuminated instead.
To define an alpenglow, the scientists agree that it is a diffused and indirect illumination, which occurs through refraction as a result of moisture and pollutants in the atmosphere. It often occurs before sunrise or just after sunset. It makes the sky look red and it eventually glows. It only lasts for a short period in the lowlands therefore not often observed.
Occurrence
The red light waves are usually the longest in the visible spectrum of the electromagnetic energy and they are also the slowest in motion. As light travels through the atmosphere, the blue color is absorbed. The slower red color is not highly absorbed and it therefore appears in the electromagnetic spectrum. As the sun sets or rises, a gradation of color rise in the eastern sky is observed which is orange-red or purple.
The color transition is actually the horizontal view of the line between day and night. The orange-red light is the sunset light that goes on rising in the sky as the sun sets. The purple light is the earth’s shadow rising to the sky. Mountains obtain the red light since they are higher and can also light the clouds after sunset (Dickson,1988).
Blue flash
Blue flashes form in a similar way as green flashes and are more difficult to see because they blend into the surrounding sky, which is also blue. It results from spectral emission of excited molecules in the air especially with oxygen and nitrogen. The molecules fall back to unionized states and consequently produce a blue light. The light is often associated with Cherenkov radiation, due to its similarity in color. It is usually followed by a heat wave which is a physical effect due to heating by the energy emitted during the event.