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Nayar, S. R. Prabhakaran; Radhika, V. N.; Revathy, K.; Ramadas, V.

doi:10.1023/a:1020565831926

Cited by 78 publications

(20 citation statements)

References 33 publications

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“…They found significant power with a 1.28 yr period, however, it was observed to vary strongly with time. A 1.3 yr periodicity has also been detected in variations of the interplanetary magnetic field and geomagnetic activity (Paularena et al 1995;Szabo et al 1995;Lockwood 2001;Mursula et al 2003;Katsavrias et al 2012) as well as in the variation of the photospheric magnetic flux (Knaack et al 2005) and in the solar wind speed (Richardson et al 1994;Prabhakaran Nayar et al 2002). Based on an analysis of the same data, however, Antia & Basu (2000) drew conclusions that contradict those of Howe et al (2000).…”

Section: Introductionmentioning

confidence: 94%

Periodicities in the X-Ray Emission From the Solar Corona

Chowdhury

Jain

Awasthi

2013

ApJ

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We have studied the time series of full disk integrated soft and hard X-ray emission from the solar corona during 2004 January to 2008 December, covering the entire descending phase of solar cycle 23 from a global point of view. We employ the daily X-ray index derived from 1 s cadence X-ray observations from the Si and CZT detectors of the "Solar X-ray Spectrometer" mission in seven different energy bands ranging between 6 and 56 keV. X-ray data in the energy bands 6-7, 7-10, 10-20, and 4-25 keV from the Si detector are considered, while 10-20, 20-30, and 30-56 keV high energy observations are taken from the CZT detector. The daily time series is subjected to power spectrum analysis after appropriate correction for noise. The Lomb-Scargle periodogram technique has shown prominent periods of ∼13.5 days, ∼27 days, and a near-Rieger period of ∼181 days and ∼1.24 yr in all energy bands. In addition to this, other periods like ∼31, ∼48, ∼57, ∼76, ∼96, ∼130, ∼227, and ∼303 days are also detected in different energy bands. We discuss our results in light of previous observations and existing numerical models.

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Section: Introductionmentioning

confidence: 94%

Periodicities in the X-Ray Emission From the Solar Corona

Chowdhury

Jain

Awasthi

2013

ApJ

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“…Searches for additional possible periodicities, other than 27 days and 11 years in solar activity indicators have been of interest for a long time. Many researchers have investigated these periodicities using various solar activity parameters and found periods such as 450-512 days (1.2-1.4 years), 280-364 days (0.8-1.0 years), 210-240 days (0.6-0.7 years), 150-170 days (0.4-0.5 years), 120-130 days, 110-115 days, 73-78 days, 62-68 days, 51-58 days, 41-47 days, and 25-37 days (Rieger et al, 1984;Lean and Brueckner, 1989;Pap, Bouwer, and Tobiska, 1990;Bai and Sturrock, 1991;Bouwer, 1992;Prabhakaran Nayar et al, 2002;Krivova and Solanki, 2002;Rybak, 2003, 2004;Kane, 2003Kane, , 2005Bai, Nevertheless, there are still disagreements between the periods determined by different studies probably due to problems in the analyzed data, the methods used, investigated time intervals, etc. These differences are possibly related to the different origin of various solar activity indicators (Bouwer, 1992).…”

Section: Introductionmentioning

confidence: 99%

Sunspot Count Periodicities in Different Zurich Sunspot Group Classes Since 1986

et al. 2014

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In this study, we used two methods to investigate the periodic behavior of sunspot counts in four categories for the time period January 1986-October 2013. These categories include the counts from simple (A and B), medium (C), large (D, E, and F), and final (H) sunspot groups. We used: i) the Multi-taper Method with red noise approximation, and ii) the Morlet wavelet transform for periodicity analysis. Our main findings are: (1) the solar rotation periodicity of about 25 to 37 days, which is of obvious significance, is found in all groups with at least a 95% significance level; (2) the periodic behavior of a cycle is strongly related to its amplitude and group distribution during the cycle; (3) the appearance of periods follow the amplitude of the investigated solar cycles, (4) meaningful periods do not appear during the minimum phases of the investigated cycles. We would like to underline that the cyclic behavior of all categories is not completely the same; there are some differences between these groups. This result can provide a clue for the better understanding of solar cycles.

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“…Furthermore, the wavelet transform does not lose the time information and gives a better signal representation by using a multiresolution analysis (Walnut, 2001) whereas the short-time Fourier transform has issues with the frequency time resolutions, which are time and frequency localized (e.g., Sifuzzaman, Islam, and Ali, 2009). Prabhakaran Nayer et al (2002), Katsavrias, Preka-Papadema, and Moussas (2012), Chowdhury et al (2014), and Singh and Badruddin (2015) employed a wavelet technique to examine periodicities of IMF B z .…”

Section: Methodsmentioning

confidence: 99%

“…a solar rotational period and ≈ 29 and ≈ 30 days. Some papers report the short-term periodicities of IMF B z without providing information on the coordinate system: Prabhakaran Nayer et al (2002) found periodicities of 14 and 27 days, Katsavrias, Preka-Papadema, and Moussas (2012) reported 29 -30-day periodicities, and Singh and Badruddin (2015) identified the solar rotation period and its harmonics.…”

Section: 30mentioning

confidence: 99%

“…Coronal mass ejections (CMEs) from the Sun can carry a magnetic structure that has a large southward component, which can cause a geomagnetic storm through magnetic reconnection with the Earth's magnetic field (e.g., Gonzalez et al, 1994;Gopalswamy, Yashiro, and Akiyama, 2007). Even when there is no major CME occurrence, a southward component of the IMF can be supplied in other ways, such as a small-scale magnetic flux rope and Alfvénic fluctuations Prabhakaran Nayer et al (2002) No information 1964 -2000 Wavelet transform 240 Katsavrias, Preka-Papadema, and Moussas (2012) No information 1966 -2010 Lomb-Scargle periodogram…”

Section: Introductionmentioning

confidence: 99%

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Origin of Solar Rotational Periodicity and Harmonics Identified in the Interplanetary Magnetic Field B z $B_{z}$ Component Near the Earth During Solar Cycles 23 and 24

Choi

Lee

2019

Sol Phys

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Periodic variations in solar-wind and geomagnetic parameters have long been recognized. In this work, we examine the periodic properties in the interplanetary magnetic field (IMF) near the Earth using satellite observations from 1996 to 2017. We pay particular attention to short-term periodicities (solar rotational period and its harmonics) of IMF B z by distinguishing between the geocentric solar ecliptic (GSE) and the geocentric solar magnetospheric (GSM) coordinates. We find that, for nearly all of the years in Solar Cycles 23 and 24, IMF B z exhibits periodic changes with a period of the solar rotation or its harmonics or both. We emphasize that these changes are far more pronounced in the GSM coordinates than in the GSE coordinates and during the northern hemisphere spring and fall seasons than the other two seasons. We attribute this result to an exquisite harmony between the Russell-McPherron effect and a well-defined IMF polarity that shows either a two-or four-sector structure for a long period of time.

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Untitled

Cited by 78 publications

References 33 publications

Periodicities in the X-Ray Emission From the Solar Corona

Periodicities in the X-Ray Emission From the Solar Corona

Sunspot Count Periodicities in Different Zurich Sunspot Group Classes Since 1986

Origin of Solar Rotational Periodicity and Harmonics Identified in the Interplanetary Magnetic Field B z $B_{z}$ Component Near the Earth During Solar Cycles 23 and 24

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