Periodicities in solar coronal mass ejections

Abstract

Mid‐term quasi‐periodicities in solar coronal mass ejections (CMEs) during the most recent solar maximum cycle 23 are reported here for the first time using the four‐year data (1999 February 5 to 2003 February 10) of the Large Angle Spectrometric Coronagraph on board the Solar and Heliospheric Observatory. In parallel, mid‐term quasi‐periodicities in solar X‐ray flares (class >M5.0) from the Geosynchronous Operational Environment Satellites and in daily averages of Ap index for geomagnetic disturbances from the World Data Center at the International Association for Geomagnetism and Aeronomy are also examined for the same four‐year time‐span. By Fourier power spectral analyses, the CME data appear to contain significant power peaks at periods of ∼358 ± 38, ∼272 ± 26, ∼196 ± 13 d and so forth, while, except for the ∼259 ± 24 d period, X‐ray solar flares of class ≳M5.0 show the familiar Rieger‐type quasi‐periods at ∼157 ± 11, ∼122 ± 5, ∼98 ± 3 d and shorter ones down to ∼34 ± 0.5 d. In the data of daily averages of Ap index, the two significant peaks at periods ∼273 ± 26 and ∼187 ± 12 d (the latter is most prominent) could imply that CMEs (periods at ∼272 ± 26 and ∼196 ± 13 d) may be proportionally correlated with quasi‐periodic geomagnetic storm disturbances. At the speculative level, the ∼138 ± 6 d period might imply that X‐ray flares of class ≳M5.0 (period at ∼157 ± 11 d) drive certain types of geomagnetic disturbances; the ∼28 ± 0.2 d periodicity is most likely caused by recurrent high‐speed solar winds at the Earth's magnetosphere. For the same three data sets, we further perform Morlet wavelet analysis to derive period–time contours and identify wavelet power peaks and time‐scales at the 99 per cent confidence level for comparisons. Several conceptual aspects of possible equatorially trapped Rossby‐type waves at and beneath the solar photosphere are discussed.

North/South Hemispheric Periodicities in the ${>}\,25\mbox{ MeV}$ Solar Proton Event Rate During the Rising and Peak Phases of Solar Cycle 24

“…In particular, Rieger et al (1984) recognized a ≈154 day periodicity in X-ray flares during Cycle 21. Such "near-Rieger" periodicities have also been reported by, for example: Lean (1990) (who identified periods of ≈ 130-185 days in a survey of multiple sunspot cycles); Bai and Cliver (1990) (in proton-producing flares); Gonzalez et al (1993) (geomagnetic activity); Cane, Richardson, and von Rosenvinge (1998) (IMF and 25 MeV proton intensity in Cycle 21, including event clustering similar to that reported here); Dalla et al (2001) (SEP events in Cycle 23); Hill, Hamilton, and Krimigis (2001) (anomalous cosmic ray intensity in the outer heliosphere); Ballester, Oliver, and Carbonell (2004) (photospheric magnetic field); Richardson and Cane (2005) (SEP intensity, ICME and geomagnetic storm sudden commencement rate, hemispheric sunspot numbers, IMF); Lou et al (2003) and Lara et al (2008) (coronal mass ejections); and Lobzin, Cairns, and Robinson (2012) (solar type III radio bursts in Cycle 23). As discussed by several of these papers, in particular Lean (1990), these periodicities vary in strength and period both from cycle to cycle and within a given cycle.…”

Periodicities in the X-Ray Emission From the Solar Corona

“…57 days 54 days Solar flare index during cycle 23 (Kilcik et al 2010) 4. 76 days 74; 72 days Solar radio flux data during ascending phase of cycle 23 (Ziȩba et al 2001); X-ray flares in cycle 23 (Lou et al 2003) 5. 96 days 98 and 92 days Solar flares and Ap during ascending phase of cycle 23 (Lou et al 2003) 6.…”

“…76 days 74; 72 days Solar radio flux data during ascending phase of cycle 23 (Ziȩba et al 2001); X-ray flares in cycle 23 (Lou et al 2003) 5. 96 days 98 and 92 days Solar flares and Ap during ascending phase of cycle 23 (Lou et al 2003) 6. 130 days 129.9; 137; 133 days Solar flare occurrence rate (Bai 2003); periodicity of solar flare index for cycle 23 (Kilcik et al 2010); solar electron flux (Chowdhury et al 2009) 7.…”

“…These parameters are the signatures of magnetic flux emergence. It is important that a number of the periodicities detected in the X-ray activity (shown in Table 1) have been found in the data of CMEs and geomagnetic activity (Lou et al 2003;Lara et al 2008). The present investigation suggests a scenario of emergence and escape of magnetic flux from the solar convection zone to the interplanetary medium through the photosphere and corona.…”

Cross-correlations between CMEs and other Solar Activity Indices

“…In Fourier space, Figure 1b Figure 1b we can find some typical periods in CC, including 191-day period, 100-day period, 66-day period, and so on. Many of them are also mentioned by Lou et al (2003). …”