Ozone Layer

The ozone layer is a layer in Earth's atmosphere which absorbs most of the Sun's UV radiation.

It contains relatively high concentrations of ozone, although it is still very small with regard

to ordinary oxygen, and is less than ten parts per million, the average ozone concentration in Earth's atmosphere being only about 0.6 parts

per million. It’s mainly found in the lower portion of the stratosphere from approximately

20 to 30 kilometers above Earth.

DepletionChlorofluorocarbons are one of the main molecules blamed for ozone depletion. Since restrictions on their release into the atmosphere, the ozone layer has recovered. The ozone layer blocks much UV light. Too much UV light has bad effects on plants and plankton. We need the ozone layer to survive here. Ozone depletion describes two distinct but related observations: a slow, steady decline of about 3 percent per decade in the total amount of ozone in Earth's stratosphere since around 1980; and a much larger, but seasonal, decrease in stratospheric ozone over Earth's polar regions during the same period.

The effects caused due to the depletion of the ozone layer

The effects caused are Destruction of the ozone layer influences health in many ways. More ultraviolet radiation is reaching Earth because of the depletion of the ozone layer, according to the World Health Organization (WHO). WHO notes that higher levels of ultraviolet radiation increase the risk for sunburn, skin damage and skin cancer in humans. These rays also potentially damage the eyes, contributing to cataracts and macular degeneration. The effects aren't limited to human health. According to the EPA, excess ultraviolet radiation may damage crops and harm marine life.

Although the concentration of the ozone in the ozone layer is very small, it is vitally

important to life because it absorbs biologically harmful ultraviolet (UV)

radiation coming from the sun. Extremely short or vacuum UV (10–100 nm) is

screened out by nitrogen. UV radiation capable of penetrating nitrogen is divided

into three categories, based on its wavelength; these are referred to as UV-A,

UV-B, and UV-C.

How was the ozone layer discovered?

The ozone layer was discovered in 1913 by the French physicists Charles Fabry and Henri Buisson . Its properties were explored in detail by the British meteorologist G.M.B Dobson, who developed a simple spectrophotometer (the Dobsonmeter) that could be used to measure stratospheric ozone from the ground. Between 1928 and 1958 Dobson established a worldwide network of ozone monitoring stations, which continue to operate to this day. "The Dobson unit, " a convenient measure of the columnar density of ozone overhead, is named in his honor.

Chlorofluorocarbon

A chlorofluorocarbon is an organic compound that contains only carbon, chlorine and fluorine , produced as a volatile derivative of methane and ethane. They are also commonly known by the DuPont brand name Freon. The most common representative is dichlorodifluoromethane (R-12 or Freon-12). Many CFCs have been widely used as refrigerants , propellants (in aerosol applications), and solvents. The manufacture of such compounds has been phased out (and replaced with products such as R-410A ) by the Montreal Protocol because they contribute to ozone depletion in the upper atmosphere.

ChemicalMechanism

Phytoplankton are the autotrophic components of the community. The name comes from the words , meaning "plant ", and , meaning "wanderer" or "drifter". Most phytoplankton are too small to be individually seen with the unaided eye. However, when present in high enough numbers, they may appear as a green discoloration of the water due to the presence of chlorophyll within their cells.

Now here’s a short video on the

discovery of the ozone hole,

F.Sherwood and Mario Molina

F.Sherwood Rowland was born in Ohio in 1927.In 1964,he became the head of the new chemistry department at the University of California at Irvine. Rowland began to study chlorofluorocarbons, or CFC’s.These chemicals were being used in spray cans, refrigerators, and air conditioners. He wondered what happened to CFC’s in the atmosphere Mario Molina was born in Mexico in 1943. He joined Rowland’s Irvine research team in 1973. Together, they discorded that CFCs break apart and form atoms of chlorine. Chlorine destroys the ozone that protects life on Earth from radiation. Rowland and Molina helped to create the worldwide ban on CFCs. It is believed that because of their work the hole in the ozone layer is now shrinking. They won the Noble Prize for their research.

Acid RainAcid rain is rain in which oxides of sulfur and nitrogen mix with the water in the atmosphere .Most acids rain comes from human sources such as car exhausted and manufacturing smoke. Sometimes acid rain comes from natural sources such as the gases released by animals and decaying plants. Wind can carry these oxides a long way from their source. The acid molecules can travel for hundreds of miles. They can even be carried into other countries. The acids created this way fall back down to Earth when it rains. Acid rain is more acid than natural rain. It may damage lakes, forests, and soil. Fish die when the water in lakes is too acidic. Acid rain can also hurt buildings. Statues made of stone can be eaten away by acid rain. The areas with the worst damage have been the eastern United States and the southeastern part of Canada.

Global WarmingThe Earth’s climate has varied throughout the Planet’s history. Geologists and paleontologists have found evidence