Surface Signs of the Biennial Atmospheric Pulse

Further e\ idelice i s prcseiited for the prcsericc of a persistent pcriodicity somewhat in excess of 2 years duration. I t s existence can be shown in the surface temperature a t widely separated stations along two ineridiaiis from Norway t o South Africa and from Canada to Cape Horn. Time series analysis by means of a narrow band-pass filter indicates phase relations among the stations, the most iinportant of theae being tha t the intertropical rcgions appear to be mutually in phase and that the higher-latitude statioiis are out of phase with the tropical stations. In the Northern Hemisphere, a t extratropical stations, the amplitudes of thc pulse arc largest when the pulsc extremes coincide with the winter months.