Schmucker, 1970 (Scripps) - MTNet

32 Bulletin, Scripps Institution of Oceanography
3. 17 Analysis of Diurnal Variations and Pulsations
Hourly means, centered on the full hour, were derived from local midnight
to local midnight on eight quiet days (if available) for each line of survey stations
and then averaged over these days. After the removal of the noncyclic
trend the resultant hourly values were harmonically analyzed in the usual
manner (cf. chap. 16 in "Geomagnetism").
Temperature effects diminished the Significance of the 1 st harmOniC, while
the consistent behavior of the 2nd and 3rJ harmonic showed that they are essentially
free from such contaminations (see tabs. 11-15). No attempts have
been made to separate or to correlate any anomalous part of the observed
diurnal variations, even though local anomalies of internal origin were
clearly recognized at many sites.
The time resolution of the records of about one minute did not allow a detailed
analysis of pulsations, based on continuous scalings. Instead, peakto-peak
values were measured, separately for each survey station and regardless
of time lags between peaks of the three components. This left in
particular the horizontal orientation of the disturbance vector undetermined.
The peak values thus obtained were squared and averaged over about ten
pulsations or pulsation trains of roughly the same period. Denoting these
squared averages with sD' sH, sz, the mean ratio of vertical to horizontal
pulsation amplitude equals
for that particular period and survey station (tab. 16).
(3.40)