The vertical distribution of ozone
As mentioned above, ozone is not evenly vertically distributed in the atmosphere. This vertical distribution of ozone is highly variable and it is important to study and understand it. Observations of the vertical distribution of ozone are performed with balloon soundings as well as other techniques. In the troposphere, below about 10 km altitude, the concentration of ozone molecules in the atmosphere is low except during some periods in summer when ozone is produced near the ground by atmospheric pollutants. Above the tropopause, which marks the transition between the troposphere and the stratosphere, the ozone concentration increases sharply and reaches its maximum in the middle stratosphere around 25 km altitude. An example of an ozone sounding is given below.
Result of the ozone sounding at 16 April 2012. The magenta line shows the vertical distribution of ozone. During an ozone sounding also temperature (°C, red), relative humidity (%, green), wind direction (°,cyan) and wind speed (m/s, blue) are recorded. The second temperature (°C, sand color) is the temperature inside the isolating box that contains the ozonesonde instrument. Full lines are the ascent profiles, dashed lines the profiles measured during the faster descent.