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IJRSP Vol.35 [2006] >
IJRSP Vol.35(5) [October 2006] >
| Title: | Long-term variations of solar, interplanetary, geomagnetic indices and comic ray intensities—A brief tutorial |
| Authors: | Kane, R P |
| Keywords: | Solar indices
Geomagnetic index
Sunspots
Cosmic ray intensity
Interplanetary magnetic field. |
| Issue Date: | Oct-2006 |
| Publisher: | CSIR |
| Abstract: | The long-term variations of the 12-month running means of several solar, interplanetary and geomagnetic parameters during the last several sunspot cycles revealed that during cycles 11-23 (1868-2004), the geomagnetic ⍺⍺ index showed several peaks within 3-5 years around the sunspot maxima, with some peaks during the declining phases of the sunspot cycles, whereas the sunspot numbers Rz showed smooth but broad maxima for 2-3 years in each cycle. The calcium plage area also showed multiple peaks but none in the declining phases. The 11-yr running means showed very good parallelism between Rz, ⍺⍺ index and global sea-surface temperature (SST). During 1940-2004, Rz and F10 (2800 MHz radio emission) showed similar 11-yr fluctuations of varying amplitudes, but coronal index, CI, showed monotonically increasing amplitudes by almost a factor of two. The open magnetic flux emanating from the sun during 1968-2004 showed long-term fluctuations, very different at low and high solar latitudes. The variations of the fluxes at low latitude (0-45o) were almost parallel to the sunspot cycle (there was a slight N-S asymmetry), while fluxes at high latitudes (45o-90o) were almost anti-parallel to the sunspot cycle. Cosmic ray neutron monitor intensities at Climax were well anti-correlated with sunspot cycle and interplanetary magnetic field (B), but poorly correlated with interplanetary number density (N), solar wind speed (V), and geomagnetic index ⍺⍺. The geomagnetic index ⍺⍺ was best correlated with the product VB. |
| Page(s): | 312-323 |
| ISSN: | 0367-8393 |
| Source: | IJRSP Vol.35(5) [October 2006]
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