Light penetration in Ocean Water

[The R/C Man]

Hey All!

I was searching the net and found this. It is just some general information but good information..... Here is the link: Light Transmission in the Ocean

Reflection, Refraction, and Color

The uppermost, sunlit layer of the ocean where 70 percent of the entire amount of photosynthesis in the world takes place is called the euphotic zone. It generally extends to a depth of 100 meters (330 feet). Below this is the disphotic zone, between 100 and 1,000 meters (330 and 3,300 feet) deep, which is dimly lit. Some animals are able to survive here, but no plants. Although the amount of light is measurable at this range of depths, there is not enough available for photosynthesis to take place. The layer of the ocean where no light at all penetrates—over 90 percent of the entire ocean area on Earth—is called the aphotic zone, where depths are more than 1,000 meters (3,300 feet).

Light Penetration.

A certain amount of incoming light is reflected away when it reaches the ocean surface, depending upon the state of the water itself. If it is calm and smooth, less light will be reflected.
If it is turbulent, with many waves, more light will be reflected. The light that penetrates the surface is refracted due to the fact that light travels faster in air than in water. Once it is within the water, light may be scattered or absorbed by solid particles. Most of the visible light spectrum is absorbed within 10 meters (33 feet) of the water's surface, and almost none penetrates below 150 meters (490 feet) of water depth, even when the water is very clear.
Greater abundances of solid particles in the water will decrease the depth of light penetration. Therefore, water near the seashore that is more turbid (cloudy) due to particles will show a decrease in light transmission, even in shallow water. This is due to large numbers of particles brought in by river systems, and biological production by microorganisms, as well as waves, tides, and other water movement picking up debris on the ocean floor.

Light Spectrum.

Water selectively scatters and absorbs certain wavelengths of visible light. The long wavelengths of the light spectrum—red, yellow, and orange—can penetrate to approximately 15, 30, and 50 meters (49, 98, and 164 feet), respectively, while the short wavelengths of the light spectrum—violet, blue and green—can penetrate further, to the lower limits of the euphotic zone. Blue penetrates the deepest, which is why deep, clear ocean water and some tropical water appear to be blue most of the time. Moreover, clearer waters have fewer particles to affect the transmission of light, and scattering by the water itself controls color. Water in shallow coastal areas tends to contain a greater amount of particles that scatter or absorb light wavelengths differently, which is why sea water close to shore may appear more green or brown in color.

[charlie]

Thanx Greg, I got that one bookmarked!!

[angeliejovereagle]

Interesting topic . Thank you for sharing. (Anybody can answer) So how does light or how much light will penetrate into the water when there is color dissolved into it (say inks, pigments, or other colorants)? Any effect? (i'm refering to water pollution which usually visually manifested by the color of the water) Thank you.

Hey All!

I was searching the net and found this. It is just some general information but good information..... Here is the link: Light Transmission in the Ocean

Reflection, Refraction, and Color

The uppermost, sunlit layer of the ocean where 70 percent of the entire amount of photosynthesis in the world takes place is called the euphotic zone. It generally extends to a depth of 100 meters (330 feet). Below this is the disphotic zone, between 100 and 1,000 meters (330 and 3,300 feet) deep, which is dimly lit. Some animals are able to survive here, but no plants. Although the amount of light is measurable at this range of depths, there is not enough available for photosynthesis to take place. The layer of the ocean where no light at all penetrates—over 90 percent of the entire ocean area on Earth—is called the aphotic zone, where depths are more than 1,000 meters (3,300 feet).

Light Penetration.

A certain amount of incoming light is reflected away when it reaches the ocean surface, depending upon the state of the water itself. If it is calm and smooth, less light will be reflected.
If it is turbulent, with many waves, more light will be reflected. The light that penetrates the surface is refracted due to the fact that light travels faster in air than in water. Once it is within the water, light may be scattered or absorbed by solid particles. Most of the visible light spectrum is absorbed within 10 meters (33 feet) of the water's surface, and almost none penetrates below 150 meters (490 feet) of water depth, even when the water is very clear.
Greater abundances of solid particles in the water will decrease the depth of light penetration. Therefore, water near the seashore that is more turbid (cloudy) due to particles will show a decrease in light transmission, even in shallow water. This is due to large numbers of particles brought in by river systems, and biological production by microorganisms, as well as waves, tides, and other water movement picking up debris on the ocean floor.

Light Spectrum.

Water selectively scatters and absorbs certain wavelengths of visible light. The long wavelengths of the light spectrum—red, yellow, and orange—can penetrate to approximately 15, 30, and 50 meters (49, 98, and 164 feet), respectively, while the short wavelengths of the light spectrum—violet, blue and green—can penetrate further, to the lower limits of the euphotic zone. Blue penetrates the deepest, which is why deep, clear ocean water and some tropical water appear to be blue most of the time. Moreover, clearer waters have fewer particles to affect the transmission of light, and scattering by the water itself controls color. Water in shallow coastal areas tends to contain a greater amount of particles that scatter or absorb light wavelengths differently, which is why sea water close to shore may appear more green or brown in color.

[reefhead728]

Great Link Greg. Learn somthing new everyday on REEFLAND.Thanks

[Ninong]

Interesting topic . Thank you for sharing. (Anybody can answer) So how does light or how much light will penetrate into the water when there is color dissolved into it (say inks, pigments, or other colorants)? Any effect? (i'm refering to water pollution which usually visually manifested by the color of the water) Thank you.

Inks? If the water has "inks" or other "pigments" in it other than color resulting from the various forms of algae and cyanobacteria, then it's really a mess.

If "water pollution" is so bad that it produces "color" in the water, then there's no telling what the light penetration will be.

Some areas of the ocean in the near coastal region will be naturally turbid, especially shallow lagoons. Light penetration will be limited by the amount of this turbidity. Certain corals and anemones thrive in this sort of environment. In fact, some of them won't do well at all in pristine water because they get a lot of their nutrition from particulate matter in these sandy lagoons. Water penetration will vary depending on the level of turbidity.

[twisted]

thanks for sharing! im always looking for a good read