|
|
 |
|
|
Ann. Geophys., 25, 875-880, 2007
www.ann-geophys.net/25/875/2007/
© European Geosciences Union 2007
Day-to-day correlation of equatorial electrojet at two stations separated by 2000 km
R. G. Rastogi1, H. Chandra1, D. Chakrabarty1, K. Kitamura2, and K. Yumoto3
1Physical Research Laboratory, Ahmedabad 380009, India
2National Institute of Information and Communications Technology, Koganei, Tokyo, Japan
3Space Environment Research Center, Kyushu University, Fukuoka, Japan
Abstract. Day-to-day fluctuations of the daily range of the geomagnetic field H at the
equatorial electrojet stations Ancon (ANC, 77.0° W) and Sao Luis (SLZ,
44.2° W) are described for the period January–June 1993. The H field
started increasing between midnight and sunrise, reaching a peak shortly
before noon. The daily range of H was maximum during March and April and
minimum during June. Regardless of the month, the range in H was
significantly larger at ANC than at SLZ. The 27-day running mean of the range of
H varied from 80 nT to 125 nT at SLZ and from 105 nT to 180 nT at ANC. The
day-to-day values of the range of H showed very faithful variations at the
two stations. The deviations of the daily range of H from its 27-day running
mean values showed good correlation between the two stations. Some large
storm-time effects were seen at both stations. The correlation was still
significant, when data were corrected for Dst index values. It is suggested
that the range in H at the two electrojet stations, separated by more than
2000 km, are affected by some common sources other than the ring current, which
need to be identified. Spectral analysis of the range of H shows remarkable
similarity at the two stations, with a dominant period of 15 days at both
stations.
Full Article in PDF (1846 KB) |
|
|
