The Odd Nitrogen Cycle
qN2O: from Earth’s surface, where it is produced by microbial activity in soil and in the
ocean.
qè In the stratosphere, some of N2O reacts to form NO, the rest is photolyzed back to N2 and
O2.
èThe NO so produced participates in the ozone-destroying nitrogen
catalytic
cycle.
èOnce for a while, the resulting NO2 molecule interacts with a hydroxyl radical (OH), producing
nitric
acid (HNO3).
èNitric Acid (HNO3) then diffuses
down into the troposphere and dissolves into rain.
q
(from The Earth System)
from UV photolysis of ozone