Abstract
Two types of parameterization of large-scale eddy fluxes are studied. The diffusion model of the flux of sensible heat is valid when the entire region between 20 and 80°N is treated as a zone of mixing. If, however, smaller latitudinal belts are considered separately as zones of mixing, erroneous results are obtained.
The parameterization of the eddy flux of momentum in terms of the zonal variance of isobaric surface heights, an average zonal wavenumber and the mean horizontal tilt of eddy axes shows that the last of these parameters is far more variable than the other two. Thus, apparently, extratropical general circulation behaves, in a limited sense, as a degraded tilted-trough vacillation
