Almost everyone has heard of UV light and knows that it is a component of the light we receive every day from the sun. UV is short for ultraviolet, and it is a wavelength of light that falls between visible light and x-rays in the spectrum. It has a shorter wavelength then visible light. It is also able to penetrate obstacles more easily. Most people also know that UV rays that cause a person’s skin to tan, and that large concentrations of UV rays can be harmful to people and even cause cancer. Some areas of the world receive much greater amounts of direct ultraviolet light then other areas, such as locations along the equator. All animals and people in that area would be subject to more intense UV ray generation then people or animals at higher latitudes. Even marine animals are subjected to more UV light in these regions because it is able to penetrate water to some extent.
How far do UV rays penetrate water?
In answering the question, “How far do UV rays penetrate water?” it is important to note that there are many variables to be considered, among them are the condition of the body of water and its clarity, various components within water can absorb UV radiation. Anyone who has ever had a sunburn from swimming will tell you that they burn worse in water then they do sunbathing on the beach. The water’s surface scatters and reflects UV rays so that a person gets hit by both the direct rays of the sun and the reflected ones as well, and it is this phenomena that contributes to the more extensive sunburn that swimmers can receive. About thirty percent of the initial UV intensity is lost at the water’s surface due to reflection. The remaining seventy percent gets scattered further as it moves deeper into the water, but the rate of scatter is difficult to estimate, and can be variable depending upon the murkiness or presence of particles in the water. A rule of thumb is that as long as light is still visible beneath the water, it is possible for there to be a presence of UV rays.