A straightforward estimation of the maximum sunspot number for cycle 23

Abstract. Using the annual number of geomagnetically quiet days (aa < 20 γ) for the year after the solar minimum, this precursor method predicts that the maximum sunspot number for cycle 23 will be 140 ± 32, indicating that cycle 23 will be similar to cycles 21 and 22.Key words. Solar physics · astrophysics and astronomy (magnetic fields; general)

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MAQNİT VƏ ELEKTROMAQNİT SAHƏLƏRİNİN FİZİOLOJİ VƏ TERAPEVTİK TƏSİR MEXANİZMLƏRİ

NATURE AND SCIENCE ◽

10.36719/aem/2019/01/39-42 ◽

2019 ◽

Vol 01 (01) ◽

pp. 39-42

Author(s):

Rahim Mahammad Rahimov ◽

◽

Khalil Firudin Khalilov ◽

Keyword(s):

Magnetic Field ◽

Biological Activity ◽

Magnetic Fields ◽

Key Words ◽

Alternating Magnetic Field ◽

Electron Polarization

Key words: magnetic field, alternating magnetic field, sinusoidal and pulsating magnetic fields, electron polarization, biological activity

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Small Scale Solar Magnetic Fields: Theory

Highlights of Astronomy ◽

10.1017/s1539299600003348 ◽

1977 ◽

Vol 4 (2) ◽

pp. 241-250 ◽

Cited By ~ 2

Author(s):

N. O. Weiss

Keyword(s):

Magnetic Fields ◽

Field Strength ◽

Solar Physics ◽

Small Scale ◽

The Sun ◽

Solar Magnetic Fields ◽

Solar Granulation ◽

The Past ◽

Maximum Field Strength ◽

Maximum Field

One of the most exciting developments in solar physics over the past eight years has been the success of ground based observers in resolving features with a scale smaller than the solar granulation. In particular, they have demonstrated the existence of intense magnetic fields, with strengths of up to about 1600G. Harvey (1976) has just given an excellent summary of these results.In solar physics, theory generally follows observations. Inter-granular magnetic fields had indeed been expected but their magnitude came as a surprise. Some problems have been discussed in previous reviews (Schmidt, 1968, 1974; Weiss, 1969; Parker, 1976d; Stenflo, 1976) and the new observations have stimulated a flurry of theoretical papers. This review will be limited to the principal problems raised by these filamentary magnetic fields. I shall discuss the interaction of magnetic fields with convection in the sun and attempt to answer such questions as: what is the nature of the equilibrium in a flux tube? how are the fields contained? what determines their stability? how are such strong fields formed and maintained? and what limits the maximum field strength?

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Distinguishing between coronal cloud prominences and channel prominences and their associations with solar and stellar flares

Proceedings of the International Astronomical Union ◽

10.1017/s1743921316002209 ◽

2015 ◽

Vol 11 (S320) ◽

pp. 278-287

Author(s):

Sara F. Martin ◽

Oddbjorn Engvold ◽

Yong Lin ◽

Jacqueline Alves da Silva

Keyword(s):

Magnetic Fields ◽

Sunspot Number ◽

Maximum Height ◽

Stellar Flares ◽

Curved Trajectories ◽

Coronal Magnetic Fields ◽

Coronal Rain

AbstractTo better understand the differences between coronal cloud prominences and channel prominences, we systematically identified and analyzed coronal cloud prominences recorded in SDO/AIA images at 304 Å from 2010 May 20 through 2012 April 28. For the 225 cases identified, their numbers vary directly with the sunspot number. Their durations are typically less than 3 days. Their most frequent maximum height is 90,000 + and - 10,000 km. We offer our hypothesis that many coronal cloud prominences originate from some of the mass of previously erupted filaments ejected high out of their filament channels; subsequently part of this mass falls and collects in leaky magnetic troughs among coronal magnetic fields which constrain the leaked mass to slowly drain downward along curved trajectories where it appears as coronal rain. Currently there is inadequate evidence for a convincing correspondence between either coronal cloud prominences or channel prominences with stellar prominences detected to date.

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A Clock in the Sun?

Proceedings of the International Astronomical Union ◽

10.1017/s1743921320000071 ◽

2019 ◽

Vol 15 (S354) ◽

pp. 127-133

Author(s):

C. T. Russell ◽

J. G. Luhmann ◽

L. K. Jian

Keyword(s):

Sunspot Number ◽

Solar Minimum ◽

Sunspot Cycle ◽

Solar Dynamo ◽

The Sun ◽

Average Period ◽

Magnetic Cycle ◽

Number Cycle ◽

As If

AbstractThe sunspot cycle is quite variable in duration and amplitude, yet in the long term, it seems to return to solar minimum on schedule, as if guided by a clock with an average period of close to 11.05 years for the sunspot number cycle and 22.1 years for the magnetic cycle. This paper provides a brief review of the sunspot number cycle since 1750, discusses some of the processes controlling the solar dynamo, and provides clues that may add to our understanding of what controls the cadence of the solar clock.

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Progress in the Measurement of Solar Magnetic Fields

International Astronomical Union Colloquium ◽

10.1017/s0252921100028980 ◽

1993 ◽

Vol 141 ◽

pp. 149-155 ◽

Cited By ~ 2

Author(s):

Guoxiang Ai

Keyword(s):

Magnetic Field ◽

Magnetic Fields ◽

White Light ◽

Historical Development ◽

Solar Magnetic Field ◽

Solar Physics ◽

Monochromatic Light ◽

Velocity Fields ◽

Solar Magnetic Fields ◽

Optical Instruments

AbstractThe historical development of optical instruments for solar physics is outlined, from white light to unpolarized and polarized monochromatic light, to Stokes profiles and simultaneous fields of view, from points to lines, plane to cube. An evolutionary series and classificaton of instruments for the solar magnetic field is described. As a next step the 2-D real time polarizing spectrograph has been proposed. The planned instruments in China for measurements of solar magnetic and velocity fields are briefly introduced.

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V. Sunspots

Transactions of the International Astronomical Union ◽

10.1017/s0251107x00006143 ◽

1985 ◽

Vol 19 (1) ◽

pp. 71-78

Author(s):

V. Buraba

Keyword(s):

Magnetic Fields ◽

Differential Rotation ◽

Solar Physics ◽

Solar Constant ◽

Dwarf Stars ◽

Solar Differential Rotation ◽

Scientific Meetings ◽

Red Dwarf Stars ◽

Stellar Magnetic Fields

Several proceedings of scientific meetings on sunspots appeared during the 1981-1984 period [The Physics of Sunsots, Cram and Thomas (eds.) 1981; see also reports of regional meetings, e.g.. Third European Solar Meeting, Oxford 1981; Nordic Astronomy Meeting, O. Hauge (ed.), Oslo 1983; 11th Regional Consultation on Solar Physics, L. Dezsö and B. Kalman (eds.), Debrecen 1983]. New interest in sunspots was aroused through observations of EUV sunspot spectra from space and was also inspired by the growing number of observations of starspots and other stellar activities [IAU Symposium No. 102, Solar and Stellar Magnetic Fields: Origin and Coronal Effects, J.O. Stenflo (ed.) 1983; Colloquium IAU No. 71 Activity in Red Dwarf Stars, Catania 1982]. Other reasons for the increased interest in sunspots and their energetics were prompted by the correlation between sunspot occurrence and the variations of the solar constant (Hudson et al. 1982) and by the use of sunspot positions for determining solar differential rotation and its change with latitude, depth, and time (Howard et al. 1984, Godoli S Mazzucconi 1982, Balthasar et al. 1984, Tuominen & Kyrolainen 1982, Adam 1983, Koch 1984).

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Evolutions of various solar indices around sunspot maximum and sunspot minimum years

Annales Geophysicae ◽

10.5194/angeo-20-741-2002 ◽

2002 ◽

Vol 20 (6) ◽

pp. 741-755 ◽

Cited By ~ 15

Author(s):

R. P. Kane

Keyword(s):

Magnetic Fields ◽

Solar Physics ◽

Total Solar Irradiance ◽

Solar Magnetic Fields ◽

Solar Cycles ◽

Sunspot Maximum ◽

Sunspot Minimum ◽

Coronal Green Line ◽

Two Indices ◽

Two Peaks

Abstract. The smoothed monthly sunspot numbers showed that in many solar cycles, (a) during years around sunspot maxima, there was only one prominent maximum, but in some cycles there was a broad plateau. If the beginning and end of these are termed as first and second maxima (separated by several months), the first maximum was generally the higher one, and the valley in between was very shallow. Solar indices at or near the photosphere generally showed similar structures with maxima matching with sunspot maxima within a month or two. Indices originating in the chromosphere and above showed two peaks in roughly the same months as sunspots (with some exceptions, notably the Coronal green line, and the Total Solar Irradiance). Yet often, the second maximum was larger than the first maximum, and the valley between the two maxima was deeper, as compared to sunspot maxima, and (b) during years around sunspot minima, the smoothed sunspot minimum could be sharp and distinct, lasting for a month or two, or could spread over several months. Among the indices originating at or near the photosphere, the Ca K line intensity showed good matching with sunspots, but the Ca Plage area, the Sunspot Group Area, and the solar magnetic fields seemed to show minima earlier than the sunspots, indicating that these activities died out first. These also showed recoveries from the minima later than sunspots. Most of the other indices originating in the chromosphere and corona attained minima coincident with sunspot minima, but in some cases, minima earlier than sunspots were seen, while in some other cases minima occurred after the sunspot minima. Thus, the energy dissipation in the upper part of the solar atmosphere sometimes lagged or led the evolution of sunspots near sunspot minimum. In a few cases, after the minimum, the indices recovered faster than the sunspots. In general, the chromospheric indices seemed to evolve similar to sunspots, but the evolution of coronal indices was not always similar to sunspots, and may differ considerably between themselves.Key words. Solar physics, astrophysics and astronomy (Corona and transition region; Magnetic fields; Photosphere and chromosphere)

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Exact equilibria for nonlinear force-free magnetic fields with its applications to astrophysics and fusion plasmas

Journal of Plasma Physics ◽

10.1017/s0022377813001050 ◽

2014 ◽

Vol 80 (2) ◽

pp. 173-195 ◽

Cited By ~ 9

Author(s):

S. M. Moawad

Keyword(s):

Magnetic Field ◽

Magnetic Fields ◽

Solar Physics ◽

Coronal Magnetic Field ◽

Fusion Plasmas ◽

Magnetic Structures ◽

Magnetic Flux Ropes ◽

Solar Prominences ◽

Confinement Fusion ◽

Nonlinear Force

AbstractKnowledge of the structure of coronal magnetic field originating from the photosphere is relevant to the understanding of many solar activity phenomena, e.g. flares, solar prominences, coronal loops, and coronal heating. In most of the existing literature, these loop-like magnetic structures are modeled as force-free magnetic fields (FFMF) without any plasma flow. In this paper, we present several exact solution classes for nonlinear FFMF, in both translational and axisymmetric geometries. The solutions are considered for their possible relevance to astrophysics and solar physics problems. These are used to illustrate arcade-type magnetic field structures of the photosphere and twisted magnetic flux ropes through the coronal mass ejections (CMEs), as well as magnetic confinement fusion plasmas.

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