scholarly journals Solar cycles: the past evolution influence

2009 ◽  
Vol 5 (S264) ◽  
pp. 155-157
Author(s):  
Alexis Klutsch ◽  
Rubens Freire Ferrero
Keyword(s):  
Solar Activity ◽  
Solar Cycle ◽  
Magnetic Activity ◽  
Measured Data ◽  
Physical Models ◽  
Periodic Pattern ◽  
Solar Cycles ◽  
Future Evolution ◽  
The Past ◽  
Physical Phenomena

AbstractThe so-calledsolar cycleis generally characterized by the quasi-periodic oscillatory evolution of the photospheric spots number. This quasi-periodic pattern has always been an intriguing question. Several physical models were proposed to explain this evolution and many mathematical data analysis were employed to determine the principal frequencies noticeable in the measured data. Both approaches try to predict the future evolution of the solar activity and to understand the physical phenomena producing these cycles. Here we present the analysis of the sunspots number evolution using the time-delay approach. Our results show than the solar cycle can also be characterized by this behavior implying the influence of the past evolution over the present one, suggesting an histeresis mechanism, linked probably with magnetic activity.

scholarly journals Prediction of Sunspot and Plage Coverage for Solar Cycle 25

2021 ◽  
Vol 922 (1) ◽  
pp. L12
Author(s):  
Valentina Penza ◽  
Francesco Berrilli ◽  
Luca Bertello ◽  
Matteo Cantoresi ◽  
Serena Criscuoli
Keyword(s):  
Solar Activity ◽  
Solar Cycle ◽  
Geomagnetic Storms ◽  
Empirical Relationship ◽  
Magnetic Activity ◽  
Solar Cycles ◽  
Spatial And Temporal Scales ◽  
Weather Events ◽  
Cycle 24 ◽  
Odd Cycles

Abstract 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 prominently the 11 yr sunspot solar cycle and its modulations. Space weather events, in the form of solar flares, solar energetic particles, coronal mass ejections, and geomagnetic storms, have long been known to approximately follow the solar cycle occurring more frequently at solar maximum than solar minimum. These events can significantly impact our advanced technologies and critical infrastructures, making the prediction for the strength of future solar cycles particularly important. Several methods have been proposed to predict the strength of the next solar cycle, cycle 25, with results that are generally not always consistent. Most of these methods are based on the international sunspot number time series, or other indicators of solar activity. We present here a new approach that uses more than 100 yr of measured fractional areas of the visible solar disk covered by sunspots and plages and an empirical relationship for each of these two indices of solar activity in even–odd cycles. We anticipate that cycle 25 will peak in 2024 and will last for about 12 yr, slightly longer than cycle 24. We also found that, in terms of sunspot and plage areas coverage, the amplitude of cycle 25 will be substantially similar or slightly higher than cycle 24.

scholarly journals Prediction of solar activity cycles by assimilating sunspot data into a dynamo model

2009 ◽  
Vol 5 (S264) ◽  
pp. 202-209 ◽  
Author(s):  
Irina N. Kitiashvili ◽  
Alexander G. Kosovichev
Keyword(s):  
Magnetic Field ◽  
Solar Activity ◽  
Solar Cycle ◽  
Sunspot Number ◽  
Magnetic Activity ◽  
Magnetic Helicity ◽  
Dynamo Model ◽  
Solar Cycles ◽  
Sunspot Data ◽  
Cycle 24

AbstractSolar activity is a determining factor for space climate of the Solar system. Thus, predicting the magnetic activity of the Sun is very important. However, our incomplete knowledge about the dynamo processes of generation and transport of magnetic fields inside Sun does not allow us to make an accurate forecast. For predicting the solar cycle properties use the Ensemble Kalman Filter (EnKF) to assimilate the sunspot data into a simple dynamo model. This method takes into account uncertainties of both the dynamo model and the observed sunspot number series. The method has been tested by calculating predictions of the past cycles using the observed annual sunspot numbers only until the start of these cycles, and showed a reasonable agreement between the predicted and actual data. After this, we have calculated a prediction for the upcoming solar cycle 24, and found that it will be approximately 30% weaker than the previous one, confirming some previous expectations. In addition, we have investigated the properties of the dynamo model during the solar minima, and their relationship to the strength of the following solar cycles. The results show that prior the weak cycles, 20 and 23, and the upcoming cycle, 24, the vector-potential of the poloidal component of magnetic field and the magnetic helicity substantial decrease. The decrease of the poloidal field corresponds to the well-known correlation between the polar magnetic field strength at the minimum and the sunspot number at the maximum. However, the correlation between the magnetic helicity and the future cycle strength is new, and should be further investigated.

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.

Solar-type periodicities in the climate variability of Northern Fennoscandia during the last three centuries: Real influence of solar activity or natural instability in the climate system

The Holocene ◽  
2021 ◽  
pp. 095968362110604
Author(s):  
Maxim Ogurtsov ◽  
Samuli Helama ◽  
Risto Jalkanen ◽  
Högne Jungner ◽  
Markus Lindholm ◽  
...  
Keyword(s):  
Solar Activity ◽  
Climate Variability ◽  
Western Siberia ◽  
Climate System ◽  
Solar Cycles ◽  
Activity Data ◽  
The Past ◽  
Proxy Records ◽  
Northern Fennoscandia ◽  
Solar Type

Fifteen proxy records of summer temperature in Fennoscandia, Northern Europe and in Yamal and Taymir Peninsulas (Western Siberia) were analyzed for the AD 1700–2000 period. Century-long (70–100 year) and quasi bi-decadal periodicities were found from proxy records representing different parts of Fennoscandia. Decadal variation was revealed in a smaller number of records. Statistically significant correlations were revealed between the timescale-dependent components of temperature variability and solar cycles of Schwabe (~11 year), Hale (~22 year), and Gleissberg (сentury-long) as recorded in solar activity data. Combining the results from our correlation analysis with the evidence of solar-climatic linkages over the Northern Fennoscandia obtained over the past 20 years suggest that there are two possible explanations for the obtained solar-proxy relations: (a) the Sun’s activity actually influences the climate variability in Northern Fennoscandia and in some regions of the Northern Hemisphere albeit the mechanism of such solar-climatic linkages are yet to be detailed; (b) the revealed solar-type periodicities result from natural instability of climate system and, in such a case, the correlations may appear purely by chance. Multiple lines of evidence support the first assumption but we note that the second one cannot be yet rejected. Guidelines for further research to elucidate this question are proposed including the Fisher’s combined probability test in the presence of solar signal in multiple proxy records.

ESTABLISHING SOLAR ACTIVITY TREND FOR SOLAR CYCLES 21 – 24

2021 ◽  
Vol 44 ◽  
pp. 100-106
Author(s):  
A.K. Singh ◽  
◽  
A. Bhargawa ◽  
Keyword(s):  
Solar Activity ◽  
Solar Cycle ◽  
Sunspot Number ◽  
Cosmic Ray ◽  
Occurrence Rate ◽  
The Sun ◽  
Solar Cycles ◽  
Lyman Alpha ◽  
Rate Versus ◽  
Alpha Index

Solar-terrestrial environment is manifested primarily by the physical conditions of solar interior, solar atmosphere and eruptive solar plasma. Each parameter gives unique information about the Sun and its activity according to its defined characteristics. Hence the variability of solar parameters is of interest from the point of view of plasma dynamics on the Sun and in the interplanetary space as well as for the solar-terrestrial physics. In this study, we have analysed various solar transients and parameters to establish the recent trends of solar activity during solar cycles 21, 22, 23 and 24. The correlation coefficients of linear regression of F10.7 cm index, Lyman alpha index, Mg II index, cosmic ray intensity, number of M & X class flares and coronal mass ejections (CMEs) occurrence rate versus sunspot number was examined for last four solar cycles. A running cross-correlation method has been used to study the momentary relationship among the above mentioned solar activity parameters. Solar cycle 21 witnessed the highest value of correlation for F10.7 cm index, Lyman alpha index and number of M-class and X-class flares versus sunspot number among all the considered solar cycles which were 0.979, 0.935 and 0.964 respectively. Solar cycle 22 recorded the highest correlation in case of Mg II index, Ap index and CMEs occurrence rate versus sunspot number among all the considered solar cycles (0.964, 0.384 and 0.972 respectively). Solar cycle 23 and 24 did not witness any highest correlation compared to solar cycle 21 and 22. Further the record values (highest value compared to other solar three cycles) of each solar activity parameters for each of the four solar cycles have been studied. Here solar cycle 24 has no record text at all, this simply indicating that this cycle was a weakest cycle compared to the three previous ones. We have concluded that in every domain solar 24 was weaker to its three predecessors.

scholarly journals Breathing of heliospheric structures triggered by the solar-cycle activity

2003 ◽  
Vol 21 (6) ◽  
pp. 1303-1313 ◽  
Author(s):  
K. Scherer ◽  
H. J. Fahr
Keyword(s):  
Solar Wind ◽  
Solar Activity ◽  
Solar Cycle ◽  
Activity Cycle ◽  
Periodic Variation ◽  
Galactic Cosmic Rays ◽  
Activity Period ◽  
Solar Cycles ◽  
Interplanetary Physics ◽  
Ram Pressure

Abstract. Solar wind ram pressure variations occuring within the solar activity cycle are communicated to the outer heliosphere as complicated time-variabilities, but repeating its typical form with the activity period of about 11 years. At outer heliospheric regions, the main surviving solar cycle feature is a periodic variation of the solar wind dynamical pressure or momentum flow, as clearly recognized by observations of the VOYAGER-1/2 space probes. This long-periodic variation of the solar wind dynamical pressure is modeled here through application of appropriately time-dependent inner boundary conditions within our multifluid code to describe the solar wind – interstellar medium interaction. As we can show, it takes several solar cycles until the heliospheric structures adapt to an average location about which they carry out a periodic breathing, however, lagged in phase with respect to the solar cycle. The dynamically active heliosphere behaves differently from a static heliosphere and especially shows a historic hysteresis in the sense that the shock structures move out to larger distances than explained by the average ram pressure. Obviously, additional energies are pumped into the heliosheath by means of density and pressure waves which are excited. These waves travel outwards through the interface from the termination shock towards the bow shock. Depending on longitude, the heliospheric sheath region memorizes 2–3 (upwind) and up to 6–7 (downwind) preceding solar activity cycles, i.e. the cycle-induced waves need corresponding travel times for the passage over the heliosheath. Within our multifluid code we also adequately describe the solar cycle variations in the energy distributions of anomalous and galactic cosmic rays, respectively. According to these results the distribution of these high energetic species cannot be correctly described on the basis of the actually prevailing solar wind conditions.Key words. Interplanetary physics (heliopause and solar wind termination; general or miscellaneous) – Space plasma physics (experimental and mathematical techniques)

scholarly journals Solar Activity and Svalbard Temperatures

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Jan-Erik Solheim ◽  
Kjell Stordahl ◽  
Ole Humlum
Keyword(s):  
Solar Activity ◽  
Solar Cycle ◽  
Winter Temperature ◽  
Positive Trend ◽  
Seasonal Temperature ◽  
Solar Cycles ◽  
Temperature Variations ◽  
Mean Temperature ◽  
Cent Level ◽  
Cycle 24

The long temperature series at Svalbard (Longyearbyen) show large variations and a positive trend since its start in 1912. During this period solar activity has increased, as indicated by shorter solar cycles. The temperature at Svalbard is negatively correlated with the length of the solar cycle. The strongest negative correlation is found with lags 10–12 years. The relations between the length of a solar cycle and the mean temperature in the following cycle are used to model Svalbard annual mean temperature and seasonal temperature variations. Residuals from the annual and winter models show no autocorrelations on the 5 per cent level, which indicates that no additional parameters are needed to explain the temperature variations with 95 per cent significance. These models show that 60 per cent of the annual and winter temperature variations are explained by solar activity. For the spring, summer, and fall temperatures autocorrelations in the residuals exist, and additional variables may contribute to the variations. These models can be applied as forecasting models. We predict an annual mean temperature decrease for Svalbard of °C from solar cycle 23 to solar cycle 24 (2009–20) and a decrease in the winter temperature of °C.

scholarly journals Temporal variations of different solar activity indices through the solar cycles 21-23

2017 ◽  
pp. 59-70 ◽  
Author(s):  
Ü.D. Gäoker ◽  
J. Singh ◽  
F. Nutku ◽  
M. Priyal
Keyword(s):  
Solar Activity ◽  
Detailed Comparison ◽  
Temporal Variations ◽  
Total Solar Irradiance ◽  
Magnetic Activity ◽  
Unexpected Finding ◽  
Solar Cycles ◽  
Percentage Decrease ◽  
Solar Activity Indices ◽  
Activity Indices

Here, we compare the sunspot counts and the number of sunspot groups (SGs) with variations of total solar irradiance (TSI), magnetic activity, Ca II K-flux, faculae and plage areas. We applied a time series method for extracting the data over the descending phases of solar activity cycles (SACs) 21, 22 and 23, and the ascending phases 22 and 23. Our results suggest that there is a strong correlation between solar activity indices and the changes in small (A, B, C and H-modified Zurich Classification) and large (D, E and F) SGs. This somewhat unexpected finding suggests that plage regions substantially decreased in spite of the higher number of large SGs in SAC 23 while the Ca II K-flux did not decrease by a large amount nor was it comparable with SAC 22 and relates with C and DEF type SGs. In addition to this, the increase of facular areas which are influenced by large SGs, caused a small percentage decrease in TSI while the decrement of plage areas triggered a higher decrease in the magnetic field flux. Our results thus reveal the potential of such a detailed comparison of the SG analysis with solar activity indices for better understanding and predicting future trends in the SACs.

scholarly journals Extreme Space Weather Events during the First Cycles of Epochs with Decreased Solar Activity

2021 ◽  
Vol 61 (6) ◽  
pp. 801-809
Author(s):  
V. N. Ishkov
Keyword(s):  
Solar Activity ◽  
Solar Cycle ◽  
Flare Activity ◽  
Solar Cycles ◽  
Geomagnetic Index ◽  
Near Earth Space ◽  
Weather Events ◽  
Solar Cyclicity ◽  
Cycle 24 ◽  
Extreme Space Weather Events

Abstract The problem of the distribution of extreme and very strong magnetic storms with intensities (G5, G4) in the first cycles (12 and 24) of epochs of lowered solar activity was considered based on homogeneous series of the geomagnetic index Aa with allowance for the modern scale of the intensity of disturbances in the near-Earth space and the scenario of solar cyclicity. The significant decrease in the number of such events and active solar phenomena in the last cycle may indicate that the sunspot and flare activity in solar cycle 12 was significantly higher than that in cycle 24, but it was significantly lower than in solar cycles of the epoch of increased solar activity.

scholarly journals Complexes of activity on the Sun in solar cycle 21

2021 ◽  
pp. 3-9
Author(s):  
Sergey Yazev ◽  
Maria Ulianova ◽  
Elena Isaeva
Keyword(s):  
Solar Activity ◽  
Solar Cycle ◽  
Natural Environment ◽  
Statistical Data ◽  
Sunspot Activity ◽  
The Sun ◽  
Solar Cycles ◽  
The North ◽  
South Asymmetry

The paper provides statistical data on solar activity complexes (ACs) observed in solar cycle 21. From the synoptic charts for the 1976–1986 sunspot activity, we have detected the regions where the sunspot generation was observed at least through three Carrington Rotations (CRs). These regions were identified as AC cores. We have compiled an AC catalogue. ACs are shown to evolve quasi-periodically, in pulses that are 15–20 rotations long. We have analyzed the North-South asymmetry in the AC location. In cycle 21, 90 % of the proton flares that affected the natural environment are shown to have occurred in ACs. We note a tendency for AC activity to decrease, as well as the manifestation of the Gnevyshev—Ohl rule in AC properties, in solar cycles 21–24.

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