Photolysis by ultraviolet (UV) radiation is the largest sink of N2O and removes ~90% of all N2O that is lost from the atmosphere. This occurs primarily in the stratosphere. The reaction photodissociates the molecule, producing ground-state N2 and excited oxygen O(1D). A minor pathway (<1%) also produces N(4S) and NO(2n) (Greenblatt and Ravishankara, 1990). Although O(1D) can combine with oxygen to form ozone, the net impact of N2O in the stratosphere is the destruction of ozone due to the production of NO from the reaction of N2O with O(1D).
The rate of photolysis varies both spatially and temporally throughout the stratosphere and is given by:
Was this article helpful?