Observations of Momentum Fluxes in a Rotating Differentially Heated Annulus with Bottom Topography.
Abstract
Radial transport of zonal momentum is examined at one level in a thermal driven rotating annulus with bottom topography. The momentum transported at that level was in response to loss of angular momentum to the annulus by friction and mountain torques. The time average momentum flux was dominated locally by momentum fluxes due to the steady flow. This flow transported slightly more momentum toward the outer wall than toward the inner wall, while the transient flow mainly transport momentum toward the inner wall. Two techniques were used to examine the zonally averaged time mean momentum flux. The first method is based on the resolution of terms into their mean and departure from mean. From this method it is found that the transient eddies transport more momentum than do the steady eddies, while at low rotation rates the mean meridional circulation at this level transports more momentum than the transient eddies. The second method involves zonal Fourier series coefficients from the u and v flow fields to illuminate the momentum transported by wave-wave interactions. The short waves, transport momentum inward. The longer waves in the annulus, however, which are typically equivalent barotropic and quasi-steady in time and space in the atmosphere, transported momentum toward the outer wall in the annulus. The result for the longer waves appears to be a phenomenon unique to the annulus.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1986
- Accession Number
- ADA177058
Entities
People
- William G. Norrie
Organizations
- Air Force Institute of Technology