SIMPLE MODELS OF THERMALLY DRIVEN MESOSPHERIC CIRCULATION,
Abstract
Possible thermally driven symmetric circulations of the mesosphere and upper stratosphere are con sidered, subject to the following major assump tions: The motions are in hydrostatic and geo strophic balance, the motions are small perturba tions about a state of rest which is defined by the horizontal average of the radiative equil ibrium temperature, the eddy fluxes of momentum and heat act only as Rayleigh friction and Newtonian conductivity, or as vertical eddy viscosity and conductivity. The assumption of small perturbations is justified by consideration of photochemical and radiative processes. The derived meridional circulations have a principal flow branch from summer pole to winter pole with maximum amplitude less than one meter per second. Good agreement with the observed amplitude, distribution, and seasonal phase ofu0he mean zonal winds is obtained if eddy viscosity and eddy conductivity parameters are assumed to be about 500 sq m/s. Radiative and photochemical processes are found to have an important damping effect on motions of this type; a radiative photochemical damping parameter can be derived having the order of magnitude 10 to the -6th power per second. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1964
- Accession Number
- AD0426717
Entities
People
- Conway Leovy
Organizations
- RAND Corporation