GEOMAGNETIC MICROPULSATION RESULTS FROM BYRD STATION AND GREAT WHALE RIVER

• Published in: Canadian Journal of Physics
• Main Authors: Jacobs, J. A., Wright, C. S.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1965
• Subjects: General Physics and Astronomy; Byrd; Byrd Station; Great Whale River
• Online Access: http://dx.doi.org/10.1139/p65-205; http://www.nrcresearchpress.com/doi/pdf/10.1139/p65-205

Early reports from the near-conjugate stations at Great Whale River and Byrd Station were based on the scanty data available in early 1961 (Lokken et al., Martin et al. 1961). The increased volume of data seems now to justify another preliminary report, in which the chief emphasis is on the time-agreement of the abrupt commencements of the numerous examples of Birkeland's "Polar Elementary Storms". Passing reference only is made to the associations at Byrd between VLF hiss and other ionospheric phenomena that are being reported by Stanford University. In the auroral zones, the magnetic activity is usually so great, even during the IQSY, that magnetograms can be employed usefully to supplement the micropulsation records. Using selected nighttime occasions, when the change in H is so sudden that a reasonable accuracy in the timing of the micropulsations can be achieved, it is found that the time differences between the two conjugate stations average ± 1 minute, although there is clear evidence that the two stations are not conjugate at all times, as evidenced by the lack of similarity of records. It is confirmed that the more abrupt changes in the magnetic field are associated with high-frequency "riders" of the order of 1 c.p.s., and that these events are often seen with the same riders at the same time at our mid-latitude stations. The return currents that show up in these lower latitudes must be taken into consideration when the areas of conjugate station agreement are considered. The daytime regime of regular (Pc) variations did not lend itself to accurate time comparison, except for very long-period oscillations at the two stations, when the maximum excursions were so far apart in time that one could reasonably assume that the indicated phase differences on the records at the two stations were correct. On this assumption, the long-period oscillations are nearly coincident at the two stations. This may usually be true for the shorter-period oscillations also, but, in many cases, considerable phase differences ...