Ten years of northern hemispheric upper air wind data have been applied to the study of year-to-year changes in certain statistics relating to the general circulation. This study focuses upon the yearly mean differential rotation of the atmosphere and the maintenance of its kinetic energy. In connection with the latter, fields of the mean meridional circulation have also been computed on a yearly basis. Some of the major findings are: (1) the range in the yearly values for the relative angular momentum of the whole atmosphere above the northern hemisphere is as large as 25%; (2) large interannual changes in the strength, location, and structure of the mean meridional cells are apparent; (3) the generation of zonal kinetic energy associated with the large-scale horizontal eddy convergence of momentum into the jet varies by as much as a factor of 2 or so in the sample of yearly values. However, the extent to which some of these changes may be associated with yearly changes in the observing station distribution or other sampling and analysis factors is not entirely known.