O3T
Description
The information of the total amount of ozone is defined as the cumulative total amount of ozone distributed throughout the atmosphere per unit area, and a unit called Dobson [DU]* is used. Ozone plays a role in protecting the ecosystem by blocking harmful ultraviolet rays from the sun and absorbing solar energy, thus directly affecting the balance of radiant energy in the Earth's atmosphere and the atmospheric circulation. Ozone distributed in the troposphere, unlike the stratosphere, is mainly produced by photochemical reactions of nitrogen oxides or volatile organic compounds known as exhaust gases, and acts as an oxidizer, which adversely affects not only humans but also plants and buildings.
※ Dobson Unit[DU], a unit representing the amount of ozone, is a unit defined as 100 DU when the vertical height occupied by 1 mm of ozone contained in the atmosphere is converted to a standard state of 0°C and 1 atm.
Applications
Since about 90% of the total amount of ozone is distributed in the stratosphere, the total amount of ozone is used as an index for monitoring changes in amount of ozone in the stratosphere. Ozone is an important atmospheric component that affects the climate and absorbs ultraviolet rays, so it is also important as an initial data for climate research and numerical weather forecasts. In addition, it provides important information for monitoring the long-term effects of freon gas destroying the ozone layer and radiating equilibrium.
The rate of ozone generation by solar ultraviolet radiation is the highest in the tropics on average, but because ozone from the tropics is slowly transported to the poles through the global ozone cycle (Brewer-Dobson cycle), the thickness of the ozone layer is thick at mid and high latitudes. It becomes relatively thin at low latitudes. The general ozone concentration is 300 DU (global average), and the total amount of ozone peaks at high latitudes in spring because the transport of ozone from the tropics to the poles increases seasonally during late autumn and winter. Therefore, the geographic distribution of the total amount of ozone and seasonal variability must be considered when interpreting the data.