Cospar International Reference Atmosphere (Cira): Trace Constituent Reference Models Part III

The trace constituent reference models presented here are of trace species in the stratosphere, mesosphere and lower thermosphere which play important roles in controlling the chemistry, radiation budget and circulation patterns of the atmosphere. These models of the climatology of trace species are considered to be reference models rather than standard models, and therefore it is not crucial that they be correct in an absolute sense. The models presented provide a benchmark of conditions in the 1980s and can be compared with present and future observations as an indication of constancy or change. The eruption of Mount Pinatubo in 1991 produced major dynamic, radiative and apparently heterogeneous chemical changes which in turn resulted in severe stratospheric perturbations in global ozone and other trace species, making it difficult to estimate unperturbed conditions in the early 1990s.
 
The trace constituent reference models presented here are of trace species in the stratosphere, mesosphere and lower thermosphere which play important roles in controlling the chemistry, radiation budget and circulation patterns of the atmosphere. These models of the climatology of trace species are considered to be reference models rather than standard models, and therefore it is not crucial that they be correct in an absolute sense. The models presented provide a benchmark of conditions in the 1980s and can be compared with present and future observations as an indication of constancy or change. The eruption of Mount Pinatubo in 1991 produced major dynamic, radiative and apparently heterogeneous chemical changes which in turn resulted in severe stratospheric perturbations in global ozone and other trace species, making it difficult to estimate unperturbed conditions in the early 1990s.