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相关论文: What's So Peculiar About the Cycle 23/24 Solar Min…

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The Birmingham Solar-Oscillations Network (BiSON) has collected helioseismic data over three solar cycles. We use these data to determine how the internal properties of the Sun during this minimum differ from the previous two minima. The…

太阳与恒星天体物理 · 物理学 2010-03-24 Sarbani Basu , Anne-Marie Broomhall , William J. Chaplin , Yvonne Elsworth , Stephen Fletcher , Roger New

The sunspot number varies roughly periodically with time. However the individual cycle durations and the amplitudes are found to vary in an irregular manner. It is observed that the stronger cycles are having shorter rise times and vice…

太阳与恒星天体物理 · 物理学 2012-05-04 Bidya Binay Karak

The 11-year sunspot cycle has many irregularities, the most promi- nent amongst them being the grand minima when sunspots may not be seen for several cycles. After summarizing the relevant observational data about the irregularities, we…

太阳与恒星天体物理 · 物理学 2015-06-18 Arnab Rai Choudhuri

We investigate solar activity by focusing on double maxima in solar cycles and try to estimate the shape of the current solar cycle (Cycle 24) during its maximum. We analyzed data for Solar Cycle 24 by using Learmonth Solar Observatory…

太阳与恒星天体物理 · 物理学 2013-09-04 Ali Kilcik , Atila Ozguc

Over the last decade there has been mounting evidence that the strength of the Sun's polar magnetic fields during a solar cycle minimum is the best predictor of the amplitude of the next solar cycle. Surface flux transport models can be…

太阳与恒星天体物理 · 物理学 2018-10-31 Lisa A. Upton , David H. Hathaway

The solar activity in the current, that is, the 24-th, sunspot cycle is analyzed. Cyclic variations in the sunspot number (SSN) and radiation fluxes in various spectral ranges have been estimated in comparison with the general level of the…

太阳与恒星天体物理 · 物理学 2018-05-01 E. A. Bruevich , V. V. Bruevich , G. V. Yakunina

Solar variability occurs over a broad range of spatial and temporal scales, from the Sun's brightening over its lifetime to the fluctuations commonly associated with magnetic activity over minutes to years. The latter activity includes most…

太阳与恒星天体物理 · 物理学 2021-11-24 Valentina Penza , Francesco Berrilli , Luca Bertello , Matteo Cantoresi , Serena Criscuoli

Using magnetic and microwave butterfly diagrams, we compare the behavior of solar polar regions to show that (i) the polar magnetic field and the microwave brightness temperature during the solar minimum substantially diminished during the…

太阳与恒星天体物理 · 物理学 2015-06-04 N. Gopalswamy , S. Yashiro , P. Mäkelä , G. Michalek , K. Shibasaki , D. H. Hathaway

Detailed study of the solar magnetic field is crucial to understand its generation, transport and reversals. The timing of the reversals may have implications on space weather and thus identification of the temporal behavior of the critical…

The Sun's magnetic field varies in multiple time scales. Observations show that the minimum between cycles 24 and 25 was the second consecutive minimum which was deeper and wider than several earlier minima. Since the active regions…

太阳与恒星天体物理 · 物理学 2022-01-19 Kiran Jain , Niket Jain , Sushanta C. Tripathy , Mausumi Dikpati

We have examined polar magnetic fields for the last three solar cycles, {$\it{viz.}$}, cycles 21, 22 and 23 using NSO Kitt Peak synoptic magnetograms. In addition, we have used SoHO/MDI magnetograms to derive the polar fields during cycle…

空间物理 · 物理学 2015-05-20 P. Janardhan , Kumar Bisoi Susanta , S. Gosain

Long-term sunspot observations and solar activity reconstructions reveal that the Sun occasionally slips into quiescent phases known as solar grand minima, the dynamics during which is not well understood. We use a flux transport dynamo…

太阳与恒星天体物理 · 物理学 2022-09-30 Chitradeep Saha , Sanghita Chandra , Dibyendu Nandy

We have analyzed available full-disc data from the Michelson Doppler Imager (MDI) on board SoHO using the "ring diagram" technique to determine the behavior of solar meridional flows over solar cycle 23 in the outer 2% of the solar radius.…

太阳与恒星天体物理 · 物理学 2015-05-19 Sarbani Basu , H. M. Antia

We have measured the physical properties of polar coronal holes from the minimum activity phase of solar cycle 23 (1996-1997) to the present minimum of solar cycle 24 (2007-2009) using the UVCS instrument on SOHO. Observations in H I Lyman…

太阳与恒星天体物理 · 物理学 2010-05-19 M. P. Miralles , S. R. Cranmer , A. V. Panasyuk , M. Uzzo

Duration of the extended solar cycles is taken into the consideration. The beginning of cycles is counted from the moment of polarity reversal of large-scale magnetic field in high latitudes, occurring in the sunspot cycle n till the…

天体物理学 · 物理学 2009-11-13 A. G. Tlatov

Maunder Minimum forms an archetype for the Grand minima, and detailed knowledge of its temporal development has important consequences for the solar dynamo theory dealing with long-term solar activity evolution. Here we reconsider the…

太阳与恒星天体物理 · 物理学 2015-05-27 J. M. Vaquero , M. C. Gallego , I. G. Usoskin , G. A. Kovaltsov

The main purpose of this study is the determination of solar minimum date of the new sunspot cycle No 24. It is provided by using of four types of mean daily data values for the period Jan 01. 2006 - Dec 31. 2009: (1) the solar radioindex…

太阳与恒星天体物理 · 物理学 2010-08-03 B. Komitov , P. Duchlev , K. Stoychev , M. Dechev , K. Koleva

In this paper, I review the results of 3-D evolution of the inner heliosphere over the solar cycle #23, based on observations of interplanetary scintillation (IPS) made at 327 MHz using the Ooty Radio Telescope. The large-scale features of…

太阳与恒星天体物理 · 物理学 2011-04-04 P. K. Manoharan

Solar activity cycle varies in amplitude. The last Cycle 24 is the weakest in the past century. Sun's activity dominates Earth's space environment. The frequency and intensity of the Sun's activity are accordant with the solar cycle. Hence…

太阳与恒星天体物理 · 物理学 2022-02-16 Wei Guo , Jie Jiang , Jing-Xiu Wang

Sunspot Cycle 25 over 3 years past the cycle minimum of December 2019. At this point, curve-fitting becomes reliable and consistently indicates a maximum sunspot number of 135+/-10 - slightly larger than Cycle 24's maximum of 116.4, but…

太阳与恒星天体物理 · 物理学 2023-10-02 Lisa A. Upton , David H. Hathaway