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IJRSP Vol.41 [2012] >
IJRSP Vol.41(1) [February 2012] >
| Title: | Pc4 Occurrence and its dependence on Kp values at low latitudes in India |
| Authors: | Ansari, I A
Khan, M T |
| Keywords: | Pc4 Geomagnetic Pulsations
MHD Waves
MHD Instabilities
Solar Wind
Magnetospheric Interactions |
| Issue Date: | Feb-2012 |
| Publisher: | NISCAIR-CSIR, India |
| PACS No.: | 94.30.cq; 96.50.Tf |
| Abstract: | A study has been
undertaken for Pc4 geomagnetic pulsations ( in 6.7 – 22.2 mHz frequency range)
at three very low latitude stations, viz. Pondicherry (PON) (geomagnetic
latitude 2.5ºN, geomagnetic longitude 151.97ºE), Nagpur (NAG) (geomagnetic
latitude 11.72ºN, geomagnetic longitude 151.93ºE), Hanle (HAN) (geomagnetic
latitude 23.38ºN, geomagnetic longitude 151.89ºE) in India employing three axis
fluxgate magnetometers, established and operated by the Indian Institute of Geomagnetism
(IIG), Navi Mumbai. Digital dynamic spectra (DDS) for the north-south (X),
east-west (Y) and vertical (Z) components of the recorded data were constructed
for each day for one year (1 January to 31 December 2005). The X and Y
components of these DDS were investigated for carrying out statistical study of
the dependence of diurnal and seasonal variations of occurrence of Pc4 events
on Kp.
The monthly variation of Pc4 occurrence has
a Kp dependence range from 0 to 9-. However, the yearly Pc4 occurrence was
found to be evenly distributed with magnetic activity over Kp range from 2- to
4 at all the three stations with the peak occurrence recorded at Kp = 3-. The
magnitudes of durations of Pc4 occurrence decreased in the station order PON,
HAN and NAG, respectively. The prominent peaks in the seasonal Pc4 occurrence
were observed at Kp = 3-, 3 for all the seasons. However, additional peaks were
observed at Kp = 1-, 1 and 1+ for the autumn season. It is also worth noting
that Pc4 in winter was observed during intense magnetic activity when 5+ <
Kp < 8+. |
| Page(s): | 39-47 |
| CC License: |  CC Attribution-Noncommercial-No Derivative Works 2.5 India |
| ISSN: | 0975-105X (Online); 0367-8393 (Print) |
| Source: | IJRSP Vol.41(1) [February 2012]
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