Phase and amplitude asymmetry in the quasi-biennial oscillation of solar Halpha flare activity

Abstract

Quasi-biennial oscillation (QBO) of solar magnetic activities is intrinsic to dynamo mechanism, but still far from fully understood. In this work, the phase and amplitude asymmetry of solar QBO of Halpha flare activity in the northern and southern hemispheres is studied by the ensemble empirical mode decomposition, the cross-correlation analysis, and the wavelet transform technique. The following results are found: (1) solar QBO of Halpha flare index in the two hemispheres has a complicated phase relationship, but does not show any systematic regularity; (2) the solar cycle mode of solar Halpha flare index in the northern hemisphere generally leads that in the southern one by 9 months for the time interval from 1966 to 2014. The possible origin of these results is discussed.

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Cited by in corpus (9)

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• The QBO-type signals in the subsurface flow fields during solar cycles 23 and 24
• The cyclic behaviour in the N-S asymmetry of sunspots and solar plages for the period 1910 to 1937 using data from Ebro catalogues
• Quasi-periodic Variations of Coronal Mass Ejections with Different Angular Widths
• The Temporal and Spatial Behaviors of CME Occurrence Rate at Different Latitudes
• Hemispheric Distribution of Solar Active Regions During Solar Cycles 23-25
• Hemispheric asymmetry in the sunspot cycle as a nonextensive phenomenon