Revisiting the Question: Does High-Latitude Solar Activity Lead Low-Latitude Solar Activity in Time Phase?

Kong, D. F.; Qu, Zhining; Guo, Qiaoling

doi:10.1088/0004-6256/147/5/97

Cited by 12 publications

(3 citation statements)

References 14 publications

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“…The author analyzed PCFs by using the polarmost filaments whose latitude is the highest of all of the PCFs found before, for a given PCF. However, we study the PCFs by measuring the average migration of PCFs (Li et al 2008;Kong et al 2014). Hyder (1965) showed a change of polarity of the polar magnetic field along with a large number of filaments reach the highest latitudes (Xu et al 2018).…”

Section: Discussionmentioning

confidence: 99%

A new comprehensive dataset of solar filaments of one-hundred-year interval (II) the poleward migration of polar crown filaments

Zheng

Deng

et al. 2021

Res. Astron. Astrophys.

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Solar filaments, hypothermia and dense structures suspended in the solar corona are formed above the magnetic polarity inversion line. Polar crown filaments (PCFs) at high-latitude regions of the Sun are of profound significance to the periodic variation of solar activities. In this paper, we statistically analyze PCFs by using full disk Hα data from 1912 to 2018, which were obtained by Kodaikanal Solar Observatory (KODA, India), National Solar Observatory (NSO, USA), Kanzelhöhe Solar Observatory (KSO, Austria), Big Bear Solar Observatory (BBSO, USA), and Huairou Solar Observing Station (HSOS, China). We first manually identify PCFs from every solar image based on the centennial data, and record the latitude and other features corresponding to the PCFs. Then we plot the PCF latitude distribution as a function of time, which clearly shows that PCFs rush to the poles at the ascending phase of each solar cycle. Our results show that the filaments drift toward mid-latitude covering solar cycle 15 to 24 after the PCFs reach the highest latitudes. The poleward migration rates of PCFs are calculated in ten solar cycles, and the range is about 0.12 degree to 0.50 degree per Carrington Rotation (CR). We also investigate the north-south (N-S) asymmetry of migration rates and the normalized N-S asymmetry index.

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Section: Discussionmentioning

confidence: 99%

A new comprehensive dataset of solar filaments of one-hundred-year interval (II) the poleward migration of polar crown filaments

Zheng

Deng

et al. 2021

Res. Astron. Astrophys.

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“…Solar filaments/prominences suspended in the solar corona are large-scale magnetic structures with relatively cool and dense materials (Tandberg-Hanssen 1995). The evolution of solar filament number with time in one solar cycle is very similar to that of sunspots (Kong et al 2014). According to the locations of solar filaments, they are classified into quiescent filaments, active-region filaments, and intermediate filaments (Engvold 1998).…”

Section: Introductionmentioning

confidence: 99%

Dynamics evolution of a solar active-region filament from quasi-static state to eruption: rolling motion, untwisting motion, material transfer, and chirality

Yan,

Li,

Chen

et al. 2020

Preprint

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To better understand magnetic structure and eruptive process of solar filaments, a solar active-region filament (labeled F2) eruption associated with a B-class flare was investigated by using high-resolution Hα data from the 1 m New Vacuum Solar Telescope (NVST), combined with EUV observations of the Solar Dynamical Observatory (SDO). The filament F2 was disturbed by another filament (labeled F1) eruption that experienced a whip-like motion. Before the filament F2 eruption, the Dopplergrams show that the southern and the northern parts of the filament F2 body exhibit blueshift and redshift along the filament spine, simultaneously. It implies that the filament F2 was rolling from one side to the other. During the filament F2 eruption, the Doppler velocity shifts of the filament body are opposite to that before its eruption. It demonstrates that the filament body exhibits an untwisting motion, which can be also identified by tracing the movement of the eruptive filament threads. Moreover, it is found that the material of the filament F2 was transferred to the surrounding magnetic field loops, which is caused by magnetic reconnection between the filament F2 and the surrounding magnetic loops. According to the right-bearing threads of the filament F2 before its eruption, it can be deduced that the filament F2 is initially supported by a sheared arcade. The following observations reveal that the twisted magnetic structure of the filament F2 formed in the eruption phase.

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“…As filaments can appear at all heliospheric latitudes and outline the border between magnetic fields with different polarities, they can be used as markers to trace the large-scale pattern of the weak background magnetic field (McIntosh 1972;Minarovjech et al 1998), especially when magnetographic observations are not available. On the other hand, studies on the occurrence of filaments can help us to better understand the distribution of large-scale fields on the solar surface, their development within a cycle, and provide useful insights into the nature of the Sun's magnetic field (Howard & Labonte 1981;Makarov & Makarova 1996;Makarov & Tlatov 1999;Rusin et al 2000;Yan et al 2011;Kong et al 2014).…”

Section: Introductionmentioning

confidence: 99%

The north-south asymmetry of solar filaments separately at low and high latitudes in solar cycle 23

Kong¹,

Qu²,

Guo³

2015

Res. Astron. Astrophys.

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We present the results of a study on the north-south asymmetry of solar filaments at low (<50 • ) and high (>60 • ) latitudes using daily filament numbers from January 1998 to November 2008 (solar cycle 23). It is found that the northern hemisphere is dominant at low latitudes for cycle 23. However, a similar asymmetry does not occur for solar filaments at high latitudes. The present study indicates that the hemispheric asymmetry of solar filaments at high latitudes in a cycle appears to have little connection with that at low latitudes. Our results support that the observed magnetic fields at high latitudes include two components: one comes from the emergence of the magnetic fields from the solar interior and the other comes from the drift of the magnetic activity at low latitudes.

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Revisiting the Question: Does High-Latitude Solar Activity Lead Low-Latitude Solar Activity in Time Phase?

Cited by 12 publications

References 14 publications

A new comprehensive dataset of solar filaments of one-hundred-year interval (II) the poleward migration of polar crown filaments

A new comprehensive dataset of solar filaments of one-hundred-year interval (II) the poleward migration of polar crown filaments

Dynamics evolution of a solar active-region filament from quasi-static state to eruption: rolling motion, untwisting motion, material transfer, and chirality

The north-south asymmetry of solar filaments separately at low and high latitudes in solar cycle 23

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