Ozone is oxygen with 3 atoms (O3). It is created by the action of ultraviolet rays on atmospheric oxygen 20 to 30 kilometers from earth’s surface to form the ozone layer. It is also generated by the action of the high voltage of thunder (lightning) on atmospheric oxygen near earth. This explains the fresh air that we smell following rain. In addition, ozone is generated by the action of sea waves on oxygen at the sea-shore with the characteristic smell.