Observation of hysteresis between solar activity indicators andp-mode frequency shifts for solar cycle 22

2000 ◽  
Vol 21 (3-4) ◽  
pp. 357-360 ◽  
Author(s):  
S. C. Tripathy ◽  
Brajesh Kumar ◽  
Kiran Jain ◽  
A. Bhatnagar
Keyword(s):  
Solar Activity ◽  
Solar Cycle ◽  
Mode Frequency ◽  
Frequency Shifts

Observation of Hysteresis between Solar Activity Indicators and p-mode Frequency Shifts for Solar Cycle 22

2000 ◽  
Vol 179 ◽  
pp. 357-360
Author(s):  
S. C. Tripathy ◽  
Brajesh Kumar ◽  
Kiran Jain ◽  
A. Bhatnagar
Keyword(s):  
Solar Activity ◽  
Solar Cycle ◽  
Magnetic Activity ◽  
Mode Frequency ◽  
Hysteresis Phenomenon ◽  
Data Sets ◽  
Frequency Data ◽  
Frequency Shifts ◽  
Intermediate Degree

AbstractUsing intermediate degreep-mode frequency data sets for solar cycle 22, we find that the frequency shifts and magnetic activity indicators show a “hysteresis” phenomenon. It is observed that the magnetic indices follow different paths for the ascending and descending phases of the solar cycle while for radiative indices, the separation between the paths are well within the error limits.

Confirmation of solar cycle-dependent intermediate-degree p-mode frequency shifts

1993 ◽  
Vol 406 ◽  
pp. 714 ◽  
Author(s):  
Edward J., Jr. Rhodes ◽  
Alessandro Cacciani ◽  
Sylvain G. Korzennik ◽  
Roger K. Ulrich
Keyword(s):  
Solar Cycle ◽  
Mode Frequency ◽  
Frequency Shifts ◽  
Intermediate Degree ◽  
Cycle Dependent

scholarly journals Comments on the Influence of Solar Activity on P-Mode Oscillation Spectra

1998 ◽  
Vol 185 ◽  
pp. 173-174
Author(s):  
L. Gizon
Keyword(s):  
Solar Activity ◽  
Structural Change ◽  
Solar Cycle ◽  
Active Region ◽  
Mode Frequency ◽  
Near Surface ◽  
Thin Region ◽  
Low Degree ◽  
Mode Oscillation ◽  
Frequency Changes

The systematic p-mode frequency changes which are observed through the solar cycle are believed to be associated with near-surface perturbations confined to the magnetically active latitudes. In this paper, we study the perturbation arising from the presence of a large “active region”, corresponding to a localized structural change in a thin region close to the photosphere. We shall ignore the difficult question of the magnitude of the effect, and simply consider some geometric and observational implications for low-degree modes.

scholarly journals Temporal changes in the frequencies of the solar p-mode oscillations during solar cycle 23

2010 ◽  
Vol 6 (S273) ◽  
pp. 389-393 ◽  
Author(s):  
E J Rhodes ◽  
J Reiter ◽  
J Schou ◽  
T Larson ◽  
P Scherrer ◽  
...  
Keyword(s):  
Solar Activity ◽  
Solar Cycle ◽  
Linear Regression ◽  
Temporal Frequency ◽  
Power Spectra ◽  
Temporal Changes ◽  
Data Sets ◽  
Regression Analyses ◽  
Frequency Shifts ◽  
Solar Cycle 23

AbstractWe present a study of the temporal changes in the sensitivities of the frequencies of the solar p-mode oscillations to corresponding changes in the levels of solar activity during Solar Cycle 23. From MDI and GONG++ full-disk Dopplergram three-day time series obtained between 1996 and 2008 we have computed a total of 221 sets of m-averaged power spectra for spherical harmonic degrees ranging up to 1000. We have then fit these 284 sets of m-averaged power spectra using our WMLTP fitting code and both symmetric Lorentzian profiles for the peaks as well as the asymmetric profile of Nigam and Kosovichev to obtain 568 tables of p-mode parameters. We then inter-compared these 568 tables, and we performed linear regression analyses of the differences in p-mode frequencies, widths, amplitudes, and asymmetries as functions of the differences in as many as ten different solar activity indices. From the linear regression analyses that we performed on the frequency difference data sets, we have discovered a new signature of the frequency shifts of the p-modes. Specifically, we have discovered that the temporal shifts of the solar oscillation frequencies are positively correlated with the changes in solar activity below a limiting frequency. They then become anti-correlated with the changes in activity for a range of frequencies before once again becoming positively-correlated with the activity changes at very high frequencies. We have also discovered that the two frequencies where the sensitivities of the temporal frequency shifts change sign also change in phase with the average level of solar activity.

Prominences and Solar Activity

1979 ◽  
Vol 44 ◽  
pp. 357-372
Author(s):  
Z. Švestka
Keyword(s):  
Solar Activity ◽  
Solar Cycle ◽  
List Type ◽  
Type Number ◽  
Flare Loops ◽  
Filament Activation

The following subjects were discussed:(1)Filament activation(2)Post-flare loops.(3)Surges and sprays.(4)Coronal transients.(5)Disk vs. limb observations.(6)Solar cycle variations of prominence occurrence.(7)Active prominences patrol service.Of all these items, (1) and (2) were discussed in most detail and we also pay most attention to them in this report. Items (3) and (4) did not bring anything new when compared with the earlier invited presentations given by RUST and ZIRIN and therefore, we omit them.

scholarly journals On the Prediction of Solar Cycles

Solar Physics ◽  
2021 ◽  
Vol 296 (1) ◽  
Author(s):  
V. Courtillot ◽  
F. Lopes ◽  
J. L. Le Mouël
Keyword(s):  
Solar Activity ◽  
Solar Cycle ◽  
Transfer Function ◽  
Singular Spectrum Analysis ◽  
Activity Cycle ◽  
Solar Activity Cycle ◽  
Planetary Motion ◽  
Data Sets ◽  
Solar Cycles ◽  
Jovian Planets

AbstractThis article deals with the prediction of the upcoming solar activity cycle, Solar Cycle 25. We propose that astronomical ephemeris, specifically taken from the catalogs of aphelia of the four Jovian planets, could be drivers of variations in solar activity, represented by the series of sunspot numbers (SSN) from 1749 to 2020. We use singular spectrum analysis (SSA) to associate components with similar periods in the ephemeris and SSN. We determine the transfer function between the two data sets. We improve the match in successive steps: first with Jupiter only, then with the four Jovian planets and finally including commensurable periods of pairs and pairs of pairs of the Jovian planets (following Mörth and Schlamminger in Planetary Motion, Sunspots and Climate, Solar-Terrestrial Influences on Weather and Climate, 193, 1979). The transfer function can be applied to the ephemeris to predict future cycles. We test this with success using the “hindcast prediction” of Solar Cycles 21 to 24, using only data preceding these cycles, and by analyzing separately two 130 and 140 year-long halves of the original series. We conclude with a prediction of Solar Cycle 25 that can be compared to a dozen predictions by other authors: the maximum would occur in 2026.2 (± 1 yr) and reach an amplitude of 97.6 (± 7.8), similar to that of Solar Cycle 24, therefore sketching a new “Modern minimum”, following the Dalton and Gleissberg minima.

Length of the Solar Cycle: An Indicator of Solar Activity Closely Associated with Climate

Science ◽  
1991 ◽  
Vol 254 (5032) ◽  
pp. 698-700 ◽  
Author(s):  
E. FRIIS-CHRISTENSEN ◽  
K. LASSEN
Keyword(s):  
Solar Activity ◽  
Solar Cycle

scholarly journals North–south asymmetry of different solar activity features during solar cycle 23

New Astronomy ◽  
2010 ◽  
Vol 15 (6) ◽  
pp. 561-568 ◽  
Author(s):  
Neeraj Singh Bankoti ◽  
Navin Chandra Joshi ◽  
Seema Pande ◽  
Bimal Pande ◽  
Kavita Pandey
Keyword(s):  
Solar Activity ◽  
Solar Cycle ◽  
Solar Cycle 23 ◽  
South Asymmetry

scholarly journals Solar Cycle Signals in the Pacific and the Issue of Timings

2012 ◽  
Vol 69 (4) ◽  
pp. 1446-1451 ◽  
Author(s):  
Indrani Roy ◽  
Joanna D. Haigh
Keyword(s):  
Solar Activity ◽  
Solar Cycle ◽  
Aleutian Low ◽  
Positive Signal ◽  
Tropical Eastern Pacific ◽  
Sea Level Pressure ◽  
The Pacific ◽  
Strong Positive Signal ◽  
The Relationship ◽  
The Tropical Pacific

Abstract The solar cycle signal in sea level pressure during 1856–2007 is analyzed. Using composites of data from January–February in solar cycle peak years the strong positive signal in the region of the Aleutian low, found by previous authors, is confirmed. It is found, however, that signals in other regions of the globe, particularly in the South Pacific, are very sensitive to the choice of reference climatology. Also investigated is the relationship between solar activity and sea surface temperatures in the tropical eastern Pacific. A marked overall association of higher solar activity with colder temperatures in the tropical Pacific that is not restricted to years of peak sunspot number is noted. The ENSO-like variation following peak years that has been suggested by other authors is not found as a consistent signal. Both the SLP and SST signals vary coherently with the solar cycle and neither evolves on an ENSO-like time scale. The solar signals are weaker during the period spanning approximately 1956–97, which may be due to masking by a stronger innate ENSO variability at that time.

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