On the role of the seasonal cycle.

Abstract

Results for the seasonal cycle contribution to the zonally averaged fluxes of momentum (200 mb) and heat (850 mb) and for the zonally averaged height variance (500 mb) in NMC data are given for 1) the winter season (seasonal cycle defined in terms of a few Legendre functions), 2) 7-year mean (seasonal cycle defined as annual and semiannual Fourier harmonics), and 3) the winter season, but utilizing the Fourier basis set appropriate for the 7-year time series. The latter calculation indicates that the interannual variability of the momentum flux is dominated by the interactions between the seasonal cycle and the meteorologically low-frequency flow.-from Author