How is the ozone layer useful to us?

Answer 1

The ozone found in our atmosphere is formed by an interaction between oxygen molecules (composed of two oxygen atoms) and ultraviolet light. When ultraviolet light hits these oxygen molecules, the reaction causes the molecules to break apart into single atoms of oxygen (UV light + O2 --> O + O). These single atoms of oxygen are very reactive, and a single atom combines with a molecule of oxygen to form ozone (O3), which is composed of three atoms of oxygen (2O + 2O2 --> 2O3).

The ozone layer is essential for human life. It is able to absorb much harmful ultraviolet radiation, preventing penetration to the earths surface. Ultraviolet radiation (UV) is defined as radiation with wavelengths between 290-320 nanometers, which are harmful to life because this radiation can enter cells and destroy the deoxyribonucleic acid (DNA) of many life forms on planet earth. In a sense, the ozone layer can be thought of as a UV filter or our planets built in sunscreen (Geocities.com, 1998). Without the ozone layer, UV radiation would not be filtered as it reached the surface of the earth. If this happened, cancer would break out and all of the living civilizations, and all species on earth would be in jeopardy (Geocities.com, 1998). Thus, the ozone layer essentially allows life, as we know it, to exist.

In order for scientists to evaluate how much ozone is in the layer, a unit of measurement called the Dobson Unit is employed. A Dobson Unit is a measurement of how thick a specific portion of the ozone layer would be if it were compressed into a single layer at zero degrees Celsius with one unit of atmospheric pressure acting on it (standard temperature and pressure - STP). Thus, one Dobson Unit (DU) is defined as .01 mm thickness at standard temperature and pressure. Figure 2 shows a column of air over Labrador, Canada. Since the ozone layer over this area would form a 3 mm thick slab, the measurement of the ozone over Labrador is 300 DU.

Answer 2

HIghly unstable,an ozone molecule readily splits up when hit by the ultra-violet radiation.The energy of the harmful ultra-violet rays is thus converted into harmless heat and never reaches the earth.The above split produces a free oxygen atom (o) and an oxygen molecule(o2) which again recombine to form a new ozone molecule in an ongoing cycle.Thus, ozone layer prevents the harmful UV rays from reaching us.
A severe depletion in the ozone layer will result in an increase in the case of skin cancer,eye cataract and suppression of the immune system in humans and other species.Food crops sensitive to UV rays could also be affected.

Answer 3

The ozone layer O3 is vital because it filters out harmful ultraviolet solar radiation. It is becoming depleted because of the air pollution of chlorofluorocarbons CFC's.