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World Forum
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Heliospheric modulation and periodicities of galactic cosmic rays during 21-24 solar cycles

Aug 5, 2015, 2:30 PM
Mississippi (World Forum)


World Forum

Churchillplein 10 2517 JW Den Haag The Netherlands
Oral contribution SH-TH Parallel SH 09 Modulation II


Prof. Karel Kudela (Institute of Experimental Physics, Slovak Academy of Sciences) Dr PARTHA CHOWDHURY (Kyung Hee University) Prof. Y.-J Moon (Kyung Hee University)


Galactic cosmic rays (GCRs) encounter an outward-moving solar wind with cyclic magnetic-field fluctuation and turbulence. This causes convection and diffusion in the heliosphere. The GCR counts from the ground-based neutron monitor stations show intensity changes that are anti-correlated with the sunspot numbers with a lag of a few months. In this paper, we make a detailed correlative study between GCRs intensity (Lomnicky stit neutron monitor station) and different solar/interplanetary parameters for cycles 21-24. We find a clear asymmetry in the cross-correlation between GCRs and solar/heliospheric activity indicators for both odd and even-numbered solar cycles. The time-lags between GCRs and solar/heliospheric parameters are found different in different solar cycles as well as in the opposite polarity states (A < 0 and A > 0) within the same solar cycle. Further, we have studied the mid-term periodicities of GCRs and found the presence of well –known Rieger ; Rieger type and quasi-biennial oscillations (QBOs) in our power spectrum. Possible explanations of the observed results are discussed in light of modulation models, including drift effects.
Collaboration -- not specified --
Registration number following "ICRC2015-I/" 255

Primary author

Dr PARTHA CHOWDHURY (Kyung Hee University)


Prof. Karel Kudela (Institute of Experimental Physics, Slovak Academy of Sciences) Prof. Y.-J Moon (Kyung Hee University)

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