Nitrous oxide, tropospheric residence time

Like methane and nitrous oxide, tropospheric ozone is a natural greenhouse gas, but one which has a short tropospheric residence time. Ozone s bending vibration occurs at 14.2 pm, near that for CO2, and thus it does not contribute much to the enhancement of the greenhouse effect since atmospheric carbon dioxide already removes much of the outgoing light in this wavelength. 

As nitrous oxide (N2O) does not react in the troposphere, it will have a long tropospheric residence time and reach the stratosphere where its oxidation leads to the formation of NO and NO2. These gases appear in catalytic cycles of reactions leading to less ozone above 25 km and more ozone below this altitude [15]. 

Nitrous oxide (N20) is produced by bacteria in the natural denitrification process. It is chemically inert in the troposphere, but in the stratosphere it is degraded photochemically. The average concentration of N20 in the troposphere is about 300 ppb, and its residence time there is 10 years. What is the global rate of production of N20 in units of kg/ year Assume that the volume of the stratosphere (at 0°C and 1 atm) is 10% that of the atmosphere. 

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