Nitrogen oxides

Nitrogen oxides (NOx) are very effective destroyers of ozone (see Figure 6.4). Nitric oxide (NO) is most important, being responsible for 5070 per cent of the natural destruction of stratospheric ozone (Hammond and Maugh 1974). It is produced in the stratosphere by the oxidation of nitrous oxide (N2O), which has been formed at the earth's surface by the action of denitrifying bacteria on nitrites and nitrates. It may also be produced in smaller quantities by the action of cosmic rays on atmospheric gases (Hammond and Maugh 1974). Major cosmic ray activity in the past, associated with supernovas, possibly produced sufficient NOx to cause a 90 per cent reduction in the ozone concentration for periods of as much as a century (Ruderman 1974). The catalytic chain reaction created by NO is a long one. Nitric oxide diffuses only slowly into the lower stratosphere where it is converted into nitric acid, and eventually falls out of the atmosphere in rain. In contrast to the other oxides of nitrogen, the presence of nitrogen dioxide (NO2) in the lower stratosphere can be beneficial to the ozone layer. It readily combines with chlorine monoxide (ClO), one of the most efficient ozone destroyers, to produce chlorine nitrate (ClONO2), a much less reactive compound, thus providing some protection for lower stratospheric ozone (Brasseur and Granier 1992).

Figure 6.3 The destruction of ozone by HO

Figure 6.3 The destruction of ozone by HO

Figure 6.4 The destruction of ozone by NO
Survival Basics

Survival Basics

This is common knowledge that disaster is everywhere. Its in the streets, its inside your campuses, and it can even be found inside your home. The question is not whether we are safe because no one is really THAT secure anymore but whether we can do something to lessen the odds of ever becoming a victim.

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  • max
    Are nitrogen oxides beneficial to the stratosphere?
    7 years ago

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