Periodic variation of the north-south asymmetry of solar activity phenomena

Verma, V. K.

doi:10.1007/bf02702386

Cited by 17 publications

(10 citation statements)

References 13 publications

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“…It can be seen that SARs occurred primarily in the northern hemisphere during solar cycles 19 and 20 and the southern hemisphere during solar cycles 21 and 22. These results confirm those of Verma (2000), who studied the N-S asymmetry of solar active phenomena including sunspot areas, solar flares, and solar active prominences. They also found that the solar active phenomena are northern dominated in solar cycles 19 and 20 and southern dominated in solar cycles 21 and 22.…”

Section: Latitudinal Distribution Of Sarssupporting

confidence: 80%

“…Li et al (1998) found that large X-ray flares occur predominantly in the southern hemisphere in the N-S asymmetry during solar cycle 22. During solar cycles 19-23, The N-S asymmetries of sunspot areas, solar flares, and solar active prominences were studied by Verma (2000). He found that these solar active phenomena occurred primarily in the northern hemisphere during solar cycles 19 and 20 and then in the southern hemisphere during solar cycles 21-23.…”

Section: Introductionmentioning

confidence: 99%

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Statistical properties of superactive regions during solar cycles 19–23

Chen

Wang

et al. 2011

A&A

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Context. Each solar activity cycle is characterized by a small number of superactive regions (SARs) that produce the most violent of space weather events with the greatest disastrous influence on our living environment. Aims. We aim to re-parameterize the SARs and study the latitudinal and longitudinal distributions of SARs. Methods. We select 45 SARs in solar cycles 21-23, according to the following four parameters: 1) the maximum area of sunspot group, 2) the soft X-ray flare index, 3) the 10.7 cm radio peak flux, and 4) the variation in the total solar irradiance. Another 120 SARs given by previous studies of solar cycles 19-23 are also included. The latitudinal and longitudinal distributions of the 165 SARs in both the Carrington frame and the dynamic reference frame during solar cycles 19-23 are studied statistically. Results. Our results indicate that these 45 SARs produced 44% of all the X class X-ray flares during solar cycles 21-23, and that all the SARs are likely to produce a very fast CME. The latitudinal distributions of SARs display the Maunder butterfly diagrams and SARs occur preferentially in the maximum period of each solar cycle. Northern hemisphere SARs dominated in solar cycles 19 and 20 and southern hemisphere SARs dominated in solar cycles 21 and 22. In solar cycle 23, however, SARs occurred about equally in each hemisphere. There are two active longitudes in both the northern and southern hemispheres, about 160• -200• apart. Applying the improved dynamic reference frame to SARs, we find that SARs rotate faster than the Carrington rate and there is no significant difference between the two hemispheres. The synodic periods are 27.19 days and 27.25 days for the northern and southern hemispheres, respectively. The longitudinal distribution of SARs is significantly non-axisymmetric and about 75% SARs occurred near two active longitudes with half widths of 45• .

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Section: Latitudinal Distribution Of Sarssupporting

confidence: 80%

Section: Introductionmentioning

confidence: 99%

Statistical properties of superactive regions during solar cycles 19–23

Chen

Wang

et al. 2011

A&A

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“…Asymmetries between the northern and the southern hemisphere were previously found in various solar indices, for instance in the distribution of flares (Reid 1968;Roy 1977;Ichimoto et al 1985;Verma 1987;Bai 1990;Garcia 1990;Atac & Ozguc 1996;Li et al 1998;Temmer et al 2001;Bai 2003b;Joshi & Joshi 2004) and filaments (Hansen & Hansen 1975;Vizoso & Ballester 1987;Duchlev & Dermendjiev 1996;Duchlev 2001), in the photospheric magnetic flux (Howard 1974;Mouradian & Soru-Escaut 1991;Knaack et al 2004), in the rotation velocities of photospheric magnetic fields (Antonucci et al 1990;Javaraiah & Gokhale 1997), and in the relative sunspot numbers and sunspot areas (Newton & Milsom 1955;Waldmeier 1971;Swinson et al 1986;Vizoso & Ballester 1989Carbonell et al 1993;Oliver & Ballester 1994;Verma 2000;Li et al 2002;Temmer et al 2002;Vernova et al 2002;Knaack et al 2004). North-south asymmetries may be due to phase differences between the magnetic activity in both hemispheres (Waldmeier 1971;Swinson et al 1986).…”

Section: Fig 1 A)mentioning

confidence: 61%

Evolution and rotation of large-scale photospheric magnetic fields of the Sun during cycles 21–23

Knaack¹,

Stenflo

Berdyugina

2005

A&A

121

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Abstract. We present the results of an extensive time series analysis of longitudinally-averaged synoptic maps, recorded at the National Solar Observatory (NSO/Kitt Peak) from 1975 to 2003, and provide evidence for a multitude of quasi-periodic oscillations in the photospheric magnetic field of the Sun. In the low frequency range, we have located the sources of the 3.6 yr, 1.8 yr, and 1.5 yr periodicities that were previously detected in the north-south asymmetry of the unsigned photospheric flux (Knaack et al. 2004, A&A, 418, L17). In addition, quasi-periodicities around 2.6 yr and 1.3 yr have been found. The 1.3 yr period is most likely related to large-scale magnetic surges toward the poles and appeared in both hemispheres at intermediate latitudes ∼30• -55• during the maxima of all three cycles 21-23, being particularly pronounced during cycle 22. Periods near

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“…Provided by them analysis revealed shift from south dominant at the end of 19th and the beginning of 20th centuries to north dominant during most of 20th century. Verma (2000) applied normalized definition (NA) of sunspot asymmetry to analysis of sunspot areas, solar flares, sudden disappearing filaments, solar active prominences and others. He found that the north-south asymmetry has periodicity about 110 years.…”

Section: Introductionmentioning

confidence: 99%

Phase asynchrony of the north-south sunspot activity

Zolotova

Ponyavin

2006

A&A

102

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Aims. Northern and Southern sunspot activities demonstrate striking synchronous behavior during a solar cycle. But sometimes synchronization fails and the north-south asymmetry occurs. The problem is the origin of the north-south asymmetry and its quasi-regular oscillations. Methods. We employed Cross-Recurrence Plot analysis to extract synchronization between the Northern and Southern sunspot activities. Results. By using Cross-Recurrence Plot technique and extracting line of synchronization we found that the north-south sunspot asymmetry is due to phase asynchrony between Northern and Southern hemispheric activities.

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Periodic variation of the north-south asymmetry of solar activity phenomena

Cited by 17 publications

References 13 publications

Statistical properties of superactive regions during solar cycles 19–23

Statistical properties of superactive regions during solar cycles 19–23

Evolution and rotation of large-scale photospheric magnetic fields of the Sun during cycles 21–23

Phase asynchrony of the north-south sunspot activity

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