ON TROPOSPHERIC CHEMICAL OSCILLATIONS

Tropospheric chemical mechanisms can generate oscillations in which th e concentrations of all reactive chemical species oscillate on timesca les ranging from days to years, depending on certain parameter ranges of specified sources for NOx; and a reduced species (e.g., carbon mono xide, isoprene, or methane). A simple carbon monoxide oxidation mechan ism is presented that exhibits oscillatory solutions qualitatively sim ilar to those found in more complex mechanisms. This allows the deriva tion of a two-variable oscillatory model for ozone and carbon monoxide . Using this model, an analytic estimation of the oscillation period i s given, the chemical sources required for oscillatory solutions are e valuated, and the mechanism for the oscillation is elucidated. Some of these: results can be extended to more complex oscillatory mechanisms .