Further studies of energy exchange between the zonal flow and the eddies
Brown, John A.
- Publisher: Co-Action Publishing
arxiv: Physics::Atmospheric and Oceanic Physics
The present study describes the results of calculations of transports of sensible heat and momentum and of exchanges of available potential energy and kinetic energy between the zonal flow and the eddies in the wave number regime. The study is based on five levels of data for the months of April, July, October 1962 and January 1963, while only two levels of data (850 and 500 mb) were available for the months of January 1959 and April, July, October 1961. The heat and momentum transport calculations in the wave number regime show that a very large fraction of the total heat and momentum transport is carried out by the very long waves during winter while a smaller percentage of the total heat and momentum transport is accounted for by these waves during the remaining part of the year. The exchange from zonal to eddy available potential energy shows a marked variation during the year with maxima during the winter and minima during the summer. The spectral distributions are such that we find a maximum for wave numbers 2 or 3 during the winter. This maximum disappears during summer, when we find the maximum at much smaller wave lengths. This energy exchange is positive in all months thus far investigated not only for the total conversion but also for the individual wave numbers. The interchange from eddy to zonal kinetic energy has a different behavior. It differs from the annual variation of the potential energy exchanges in that we find the maximum value during fall. The spectra are very irregular with no clearly defined maxima and minima. This energy exchange is positive for all months investigated so far except for January 1963, but the average values are always much smaller than the average exchanges between the two forms of available potential energy. It is demonstrated that a very large fraction of the total (negative) interchange during January 1963 is accounted for by wave number 3. The results of our calculations are compared with those of other investigators showing fair qualitative agreement.DOI: 10.1111/j.2153-3490.1964.tb00158.x