VERTICAL MOTIONS AND NITRIC OXIDE IN UPPER MESOSPHERE

The photochemical equations governing the distribution of nitric oxide in the upper mesosphere are examined by means of a scale analysis. An equation obtained earlier by Nicolet is shown to govern the distribution of nitric oxide, and this equation is subsequently modified to include transport by atmospheric motion. Solutions of the governing equation are obtained for the case of an altitude-independent vertical velocity, assuming the existence of a source of nitric oxide above the 85 km level. Vertical velocities of the order of those expected in winter to be associated with either planetary waves or with a mean meridional cell are shown to transport a substantial amount of nitric oxide into the 70-85 km region. The detailed mechanism of the transport is discussed for each of these modes of atmospheric motion. Modifications that may be produced by transient planetary waves are considered. © 1968 Pergamon Press.