Stationary waves in the winter stratosphere: seasonal and interannual variability.

Monthly average satellite and conventional data are used to determine the zonal mean wind and stationary waves 1 and 2 in the northern winter stratosphere for January 1973 through February 1977. Wave propagation is diagnosed with the aid of the Eliassen-Palm flux and the refractive index squared. Interannual variability in zonal mean wind and stationary wave amplitudes is greatest during the second half of winter (January-March), partially as a consequence of the irregular occurrence of major sudden warmings during those months. Both the seasonal trend and the interannual variability of the amplitude of wave 1 reflect variations in zonal mean wind, and the corresponding refractive index. -from Author