BEHAVIOR OF THE PRINCIPAL HARMONICS OF SELECTED 5-DAY MEAN 500-MB. CHARTS

Abstract

The coefficients A_n and B_n, and the percentage of the total height variance accounted for by each harmonic were computed for the first three longitudinal harmonics of 5-day mean 500-mb. height-contour charts at each 10° of latitude from 20° N. to 80° N. from December 1, 1959, to May 31, 1960. The phase angles and amplitudes of the first three harmonics were computed at 30° N., 50° N., and 70° N. and plotted as a function of time. Retrogression of the waves was found at high and low latitudes, while relatively stationary conditions prevailed at middle latitudes. The correlation coefficient between the contribution of the sum of the first three harmonics and the entire wave train was found to be almost +0.9.