1. Reflection: A portion of the light is reflected off the surface of the water. This reflected light is what we see when we look at a pond from above. The amount of light reflected depends on the angle at which the light hits the surface and the wavelength of the light.
2. Refraction: As light passes from air into water, it undergoes refraction, which means it changes direction. This is because the speed of light is slower in water than in air. Refraction causes the light rays to bend as they enter the water, making objects underwater appear closer to the surface than they actually are.
3. Absorption: Some of the light that enters the water is absorbed by water molecules and other particles in the water. The amount of light absorbed depends on the wavelength of the light and the clarity of the water. Shorter wavelengths, such as blue and violet light, are absorbed more strongly than longer wavelengths, such as red and orange light. This is why deep water appears blue or green.
4. Scattering: Light can also be scattered by particles suspended in the water, such as sediment, plankton, and air bubbles. Scattering causes light to be redirected in different directions, resulting in the diffuse glow that we see in underwater environments. The scattering of light is more pronounced for shorter wavelengths, which is why the water often appears bluish or greenish.
5. Total Internal Reflection: In certain conditions, light can undergo total internal reflection when it hits the surface of the water from underwater. This occurs when the angle of incidence (the angle at which the light strikes the surface) is greater than the critical angle for water. At the critical angle, the light is completely reflected back into the water, and none of it is transmitted into the air. Total internal reflection is what allows fish and other aquatic creatures to see clearly underwater.
These interactions of light with the surface of a pond play a crucial role in determining the appearance of the water body and the underwater environment. They affect the color, clarity, and visibility of the water and influence the behavior and survival of aquatic organisms.