Neutral/ion chemistry of sodium in the stratosphere and mesosphere. Technical report
Part A of the report presents results from model calculations of the diurnal behavior of the neutral and ionic sodium species. It is shown that the concentration of Na/sup +/ above 90 km exerts a direct influence on the topside scale height of the atomic sodium layer in the mesosphere. The abundance of Na/sup +/ is controlled by the reaction rate for the clustering reaction which is the rate limiting step for the conversion of Na/sup +/ to Na. Downward transport of Na/sup +/ due to ion drift is also effective in reducing the sodium abundance around 90 km. The model can successfully simulate the observed topside scale height of the sodium layer by either using a slow rate for the clustering reaction or incorporating transport of Na/sup +/. Part B assesses the possible impact of sodium species on the stratospheric chlorine cycle. Recent measurements of kinetic rates suggest that the bulk of the sodium species could be in the form of NaCl in the stratosphere. Since the sodium abundance is three orders of magnitude smaller than that of chlorine, NaCl is not likely to be an important chlorine reservoir. Photolysis of NaCl could provide a mechanism for recycling HCl to Cl in the lower stratosphere if it is as fast as 0.001/s. However, the mechanism would not be effective if there exists another more stable form of sodium compound, such as NaHC03 or polymers of NaCl. Keywords: Ionospheric chemistry; Photochemistry; Ion chemistry; Upper atmosphere; Ionospheric models; D region; E region.
- Research Organization:
- Atmospheric and Environmental Research, Inc., Cambridge, MA (USA)
- OSTI ID:
- 5796921
- Report Number(s):
- AD-A-164636/3/XAB
- Country of Publication:
- United States
- Language:
- English
Similar Records
A new numerical model of the middle atmosphere. 2: Ozone and related species
Minor constituents in the stratosphere and mesosphere
Related Subjects
GENERAL PHYSICS
D REGION
SODIUM
E REGION
ATMOSPHERIC CHEMISTRY
CHLORINE
HEIGHT
IONS
LAYERS
MESOSPHERE
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
SODIUM COMPOUNDS
STRATOSPHERE
TRANSPORT
ALKALI METAL COMPOUNDS
ALKALI METALS
CHARGED PARTICLES
CHEMICAL REACTIONS
CHEMISTRY
DECOMPOSITION
DIMENSIONS
EARTH ATMOSPHERE
ELEMENTS
HALOGENS
IONOSPHERE
METALS
NONMETALS
PLANETARY IONOSPHERES
640201* - Atmospheric Physics- Auroral
Ionospheric
& Magetospheric Phenomena