Disturbances and eddy fluxes in Northern Hemisphere flows: instability of three-dimensional January and July flows.

A study is made of the instability properties of three-dimensional flows for 1978. The growth rates and phase frequencies of growing baroclinic disturbances and the perturbation stream functions and eddy heat and momentum fluxes are obtained using a five-level spherical quasi-geostropic spectral model. It is found that the presence of the planetary waves in the basic states cause a considerable increase in the growth rates of the fastest growing modes, compared with the case for zonally averaged January and July flows.-from Author