The impact of asymmetrical distribution of solar activity on geomagnetic indices throughout five solar activity cycles

El‐Borie, M. A.; El-Taher, A. M.; Thabet, A. A.; Bishara, A. A.

doi:10.1016/j.asr.2019.03.040

Cited by 12 publications

(3 citation statements)

References 24 publications

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“…The solar N-S asymmetry is considered as one of the most interesting properties of solar activity and studied in many manifestations of solar activity such as flares, prominences, sunspots, filaments, etc. (Howard 1974;Roy 1977;Yadav et al 1980;Swinson et al 1986;Ballester 1987, 1990;Carbonell et al 1993;Oliver and Ballester 1994;Joshi 1995;Javaraiah and Gokhale 1997;Verma 2000;Ataç and Özgüç 2001;Temmer et al 2002;Joshi and Joshi 2004;Ballester et al 2005;Javaraiah and Ulrich 2006;Zaatri et al 2006;Temmer et al 2006;Carbonell et al 2007;Li et al 2009a,b;Gigolashvili et al 2011;Chowdhury et al 2013;Chandra et al 2013;Obridko et al 2014;Joshi et al 2015;Zhang et al 2015;Javaraiah 2016;Bruevich and Yakunina 2017;Deng et al 2017;Gurgenashvili et al 2017;Xie et al 2018;El-Borie et al 2019;Li et al 2019).…”

Section: Introductionmentioning

confidence: 99%

North-South Distribution and Asymmetry of GOES SXR Flares during Solar Cycle 24

Joshi¹,

Chandra

2020

Open Astronomy

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Here we present the results of the study of the north-south (N-S) distribution and asymmetry of GOES soft X-ray (SXR) flares during solar cycle 24. The period of study includes ascending, maximum and descending phases of the cycle. During the cycle double-peaked (2011, 2014) solar maximum has occurred. The cycle peak in the year 2011 is due to B-class flares excess activity in the northern hemisphere (NH) whereas C and M class flares excess activity in the southern hemisphere (SH) supported the second peak of the cycle in 2014. The data analysis shows that the SXR flares are more pronounced in 11 to 20 degree latitudes for each hemisphere. Cumulative values of SXR flare count show northern excess during the ascending phase of the cycle. However, in the descending phase of the cycle, southern excess occurred. In the cycle a significant SH dominated asymmetry exists. Near the maximum of the cycle, the asymmetry enhances pronouncedly and reverses in sign.

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Section: Introductionmentioning

confidence: 99%

North-South Distribution and Asymmetry of GOES SXR Flares during Solar Cycle 24

Joshi¹,

Chandra

2020

Open Astronomy

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“…The study confirmed the existence of significant yearly N-S throughou aa, Ap and Kp asymmetries shifted to the southern solar hemisphere. More recently, El-Borie et al [17] studied the influence of hemispheric distribution of solar activity feature represented by SSAs on the geomagnetic indices during the period 1967-2016. The results confirmed the possible connection between geomagnetic activity disturbances and the sign of the dominance of the solar activity, i.e.…”

Section: Introductionmentioning

confidence: 99%

The Influence of Hemispheric Solar Activity Features on the Interplanetary Plasma Parameters throughout 1967 ̶ 2017

El-Taher

El‐Borie

Bishara

et al. 2021

Arab Journal of Nuclear Sciences and Applications

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In this article, we have examined the possible influence of hemispheric solar activity features on the interplanetary plasma parameters. For this purpose, the daily data of sunspot areas (SSAs) and sunspot numbers (SSNs) as well as the interplanetary plasma parameters (interplanetary magnetic field (IMF) magnitude B, plasma density n, plasma velocity V, plasma temperature T, and plasma dynamic pressure P . The daily data of each interplanetary plasma parameter has been classified into two groups, northern (N) and southern (S) sorted groups based on the dominance of hemispheric SSAs or SSNs. The yearly averages of the sorted N and S groups have been calculated for each plasma parameter. The asymmetry index (N-S) for each parameter between the northern and the southern sorted group has been calculated. The asymmetry of B over the solar activity cycles is not detectable, indicating that the solar cycles are magnetically symmetric, in agreement with the findings of [1]. During the solar cycles 20, 21, and 24, the solar plasma for the southern sorted group was faster (hotter) by 20.3 km/s (15.7×10 3 o K), 13 km/s (8×10 3 o K), and 29 km/s (14.5×10 3 o K) than that for the northern sorted group, respectively. In contrast, during the solar cycle 23, the solar plasma for the southern sorted group was slower (colder) by 7.4 km/s (7.2×10 3 o K) than that for the northern sorted one.

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“…Among the various indices to quantitatively describe the geomagnetic activity, the aa index (Mayaud, 1972), derived from the 3-hourly K indices at two near-antipodal midlatitude stations in England and Australia, is the longest time series (since 1868) 5 and has been widely used for analyzing long-term trends in the global geomagnetic activity (Russell and Mulligan, 1995;Marat et al, 2017;Du, 2011a;El-Borie et al, 2019) and for analyzing its correlation with both climate change (Cliver et al, 1998;Dobrica et al, 2009;Gavrilyeva et al, 2017) and solar activity (Echer et al, 2004;Prestes et al, 2006;Lukianova et al, 2009;Du, 2011b,c;Singh and et al, 10 2019). The minimum aa index (aa min ), at or near the solar minimum of the solar cycle, has been widely used in predicting the maximum amplitude of the sunspot cycle (R m ), the so-called Ohl's precursor method (Ohl, 1979;Brown and Williams, 1969;Du et al, 2009).…”

Section: Introductionmentioning

confidence: 99%

Predicting the maximum aa/Ap index through its relationship with the preceding minimum

2020

Preprint

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Abstract. Predicting the strength and peak time of geomagnetic activity for the ensuing cycle 25 is important in space weather service for planning future space missions. The minimum aa geomagnetic index around the solar minimum has been often used to predict the maximum amplitude of sunspot cycle, but seldom used to directly predict the maximum aa index. This study analyzed the relationships between the maxima and minima of both the geomagnetic aa and Ap indices for the 11-year cycle. The maximum aa index is found to be well correlated to the preceding minimum with a correlation coefficient of r = 0.860. As a result, the maximum aa index for the ensuing cycle 25 is predicted to be aamax(25) = 26.9 ± 2.6. This value is equivalent to Apmax(25) = 17.3 ± 1.8 ± 1.2 if employing the high correlation between aa and Ap (r = 0.939). The maximum Ap index is also found to be well correlated to the preceding minimum with a correlation coefficient of r = 0.862. Based on this correlation, the maximum Ap index is predicted to be a slightly higher value of Apmax(25) = 19.0 ± 1.6. The rise time of the aa (Ap) index for the 11-year cycle is found to be nearly uncorrelated to the following maximum, r = −0.16 (−0.17). If the data point for cycle 24 (which is far from others) were not considered, the rise time of the Ap index for the 11-year cycle would be weakly correlated to the following maximum, r = −0.404 at a confidence level of 62 %. The rise time for cycle 25 would be roughly estimated to be 89.9 ± 31.6 (months), implying that the geomagnetic activity for the ensuing cycle 25 would peak around April 2025 ± 32 months.

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The impact of asymmetrical distribution of solar activity on geomagnetic indices throughout five solar activity cycles

Cited by 12 publications

References 24 publications

North-South Distribution and Asymmetry of GOES SXR Flares during Solar Cycle 24

North-South Distribution and Asymmetry of GOES SXR Flares during Solar Cycle 24

The Influence of Hemispheric Solar Activity Features on the Interplanetary Plasma Parameters throughout 1967 ̶ 2017

Predicting the maximum aa/Ap index through its relationship with the preceding minimum

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