Abstract
The sunspots are widely used to measure the rotational rate of solar surface. We are interested in analysis of the temporal evaluation of the short-term period present in sunspot time series (i.e. sunspot number and area) during the ascending phase of Solar Cycle 24. For the better understanding of variation in solar activity originated at different layers of the solar atmosphere with respect to sunspot cycles, we study the phase relation between sunspot numbers and sunspot areas using cross correlation analysis techniques based on extended wavelet based approaches such as continuous wavelet transform, cross-wavelet transform, and wavelet coherence. In this study we found the short-term periodicity “27 days-rotational rate of Sun” for current solar cycle 24 (January2008-May2013), which suggested that the Solar Cycle24 has minimum solar activity. We have also investigated the correlation between both parameters and identify the unusual conditions in space weather.
Highlights
The helioseismic revealed that the solar magnetic field is created at the base of convention zone through a dynamo mechanism
The relation between total corrected sunspot area A and sunspot number R is not good for daily values, it has often been stated that the relationship becomes better when using monthly or yearly averages
It is found that large variations at the time flow have a periodicity of around 27 day for both sunspot number and the sunspot area
Summary
The helioseismic revealed that the solar magnetic field is created at the base of convention zone (tachocline) through a dynamo mechanism. Because of buoyancy, this magnetic field rises in the upward direction and appears on the solar surface as sunspots, plages, and networks. The corresponding rotation period of the Sun found by [4] in their study of solar wind parameters of the interplanetary magnetic field (IMF). Sunspot numbers and sunspot areas are historically used to describe the long-term, mid–term and short-term quasi periodicities. Mid-term quasi-periodicities (one to several months or longer) was used in the diagnostics of various solar flare activities and sunspot numbers or areas etc. The relation between total corrected sunspot area A (in millionths of the visible solar hemisphere) and sunspot number R is not good for daily values, it has often been stated that the relationship becomes better when using monthly or yearly averages
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