On interannual variations of angular momentum and zonal kinetic energy in the atmosphere

Abstract

Interannual changes in various quantities involved in the atmospheric balances of angular momentum and zonal kinetic energy for the northern hemisphere have been analyzed for the five year period beginning May 1, 1958. The data used consists of daily upper-air measurements of the horizontal wind field taken from a hemispheric network of over 700 stations. Results are presented for the most part in the form of meridional cross-sections through the atmosphere and profiles of vertical averages of the quantities studied. The fields of quantities dependent on the mean meridional flow show large year-to-year fluctuations, though the well-known fact that such fields are difficult to measure accurately must be borne in mind. By comparison, the mean zonal flow field and the horizontal transient eddy momentum flux are relatively stable. However, variations that they do display may be of considerable interest for certain purposes.