Abstract
An empirical study has been made which compares the large-scale meridional eddy momentum transport with some selected zonal mean quantities by calculating correlations between them as a function of time lag and latitude. The basic dataset was the daily 200 mb geopotential and temperature grid analysis fields of the German Weather Service over an eight-year period. The results gave generally only small correlation values but show that a meridional covergence of the eddy transport leads to an increasing zonal mean wind or meridional curvature of the zonal wind component. The correlation maxima are reached at a time lag of +2 days. The same tendency can be recognized from an examination of the relation which Green found between the convergence of momentum transport and the transport of sensible heat and potential vorticity. An introductory discussion of two-dimensional models is given which focuses on the methods of parameterizing the eddy transports.
