Examination of the relationship between solar activity and earth seismicity during the weak solar cycle 23

The relations between sunspot number, sunspot areas, and solar 10.7 cm radio flux, solar proton events and earthquakes of magnitude M ≥ 5 and M ≥ 8 during the interval from 1996 to 2008 of the solar cycle 23 have been analyzed in this work. We have found that there is a direct relation between solar activity and Earth seismic activity for M ≥ 5 and M ≥ 8, near the maximum of the solar cycle 23, and an inverse relation between them at the descending phase of the cycle.

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Mid-term Periodicities in Solar Radio Emission Corresponding to Sunspot Number During Solar Cycle 23

Solar Physics ◽

10.1007/s11207-021-01793-6 ◽

2021 ◽

Vol 296 (3) ◽

Author(s):

Mahender Aroori ◽

Panditi Vemareddy ◽

Partha Chowdhury ◽

Ganji Yellaiah

Keyword(s):

Solar Cycle ◽

Radio Emission ◽

Sunspot Number ◽

Solar Radio ◽

Solar Radio Emission ◽

Solar Cycle 23

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

New Astronomy ◽

10.1016/j.newast.2010.01.005 ◽

2010 ◽

Vol 15 (6) ◽

pp. 561-568 ◽

Cited By ~ 13

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

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Solar Cycle Signals in the Pacific and the Issue of Timings

Journal of the Atmospheric Sciences ◽

10.1175/jas-d-11-0277.1 ◽

2012 ◽

Vol 69 (4) ◽

pp. 1446-1451 ◽

Cited By ~ 30

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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FEATURES OF DISTRIBUTION OF SEISMIC ACTIVITY IN DIFFERENT REGIONS OF EARTH OVER PHASES OF THE 11-YEAR SOLAR CYCLE

Solar-Terrestrial Physics ◽

10.12737/stp-61202011 ◽

2020 ◽

Vol 6 (1) ◽

pp. 93-101

Author(s):

Valeriy Ruzhich ◽

Elena Levina

Keyword(s):

Solar Cycle ◽

Seismic Activity ◽

Time Parameter ◽

Superposition Method ◽

Medium Term ◽

Activity Distribution ◽

Middle Latitudes ◽

Northern Regions ◽

Relationship Of ◽

The Relationship

We discuss the relationship of solar activity with the seismicity of Earth and reasons for the differences in the results of studies of various authors. Using the epoch superposition method, we analyze the differences in seismic activity distribution over phases of the 11-year solar cycle for the whole world, hemispheres, sectors, latitudinal belts, and individual regions. The northeastern sector of Earth has been shown to make the main contribution to the planetary distribution of seismic activity over phases of the 11-year solar cycle. We have revealed a pattern in the distribution of seismic activity over latitudinal belts: the solar cycle phases, at which the main maximum of seismic activity occurs, increase with increasing latitude in both hemispheres. For some regions, the results may differ from the generalized results for Earth due to the influence of local geodynamic conditions during the destruction of the earth's crust. In middle latitudes, the maximum number of earthquakes is shifted to the later phases of the solar cycle from west to east, which was not found for the northern regions. We discuss possible reasons for various manifestations of solar-terrestrial relationships for different regions, taking into account their different structure and geodynamic development modes. The presence of pronounced maxima of the seismic activity distribution over the 11-year solar cycle phases allows us to use them for refining the “time” parameter in the medium-term prediction of dangerous earthquakes.

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ESTABLISHING SOLAR ACTIVITY TREND FOR SOLAR CYCLES 21 – 24

PHYSICS OF AURORAL PHENOMENA ◽

10.51981/2588-0039.2021.44.023 ◽

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.

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The Impact of Sunspots Number on Critical Frequencies foF2 for the IONOSPHERIC Layer-F2 Over Erbil Station During the Down Phase of Solar Cycle 24

NeuroQuantology ◽

10.14704/nq.2021.19.8.nq21128 ◽

2021 ◽

Vol 19 (8) ◽

pp. 157-168

Author(s):

Wafaa H.A. Zaki

Keyword(s):

Solar Activity ◽

Solar Cycle ◽

Sunspot Number ◽

Critical Frequency ◽

Radio Communication ◽

Ionospheric Layer ◽

Solar Cycle 24 ◽

Critical Frequency Fof2 ◽

Cycle 24 ◽

The Impact

The ionosphere layer (F2) is known as the most important layer for High frequency (Hf) radio communication because it is a permanent layer and excited during the day and night so it is able to reflect the frequencies at night and day due to its high critical frequency, and this layer is affected by daily and monthly solar activity. In this study the characteristics and behavior of F2 layer during Solar cycle 24 were studied, the effect of Sunspots number (Ri) on the critical frequency (foF2), were investigated for the years (2015, 2016, 2017, 2018, 2019, 2020) which represents the down phase of the solar cycle 24 over Erbil station (36° N, 44° E) by finding the critical frequency (foF2) values, the layer’ s impression times are determined for the days of solstice as well as equinox, where the solar activity was examined for the days of the winter and summer solstice and the days of the spring and autumn equinoxes for a period of 24 hours by applied the International Reference Ionosphere model IRI (2016). The output data for foF2 were verified by using the IRI-Ne- Quick option by specifying the time, date and Sunspot number parameters. Statistical analysis was caried out through the application of the Minitab (version 2018) in order to find the correlation between the critical frequency (foF2) of Ionospheric layer F2 and Sunspot number. It was concluded that the correlation is strong and positive, this indicate that critical frequency (foF2) increase with increasing Sunspots number (Ri) for solar cycle 24.

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Solar Activity and Global Temperature

International Astronomical Union Colloquium ◽

10.1017/s0252921100024830 ◽

1994 ◽

Vol 143 ◽

pp. 339-347 ◽

Cited By ~ 1

Author(s):

Eigil Friis-Christensen ◽

Knud Lassen

Keyword(s):

Solar Activity ◽

Solar Cycle ◽

Sunspot Number ◽

Cycle Length ◽

Global Temperature ◽

Energy Output ◽

Temperature Record ◽

Reconstructed Temperature ◽

Solar Cycle Length

A major problem in the determination of the magnitude of a possible solar effect on climate is that no physical parameter of solar energy output exists that has been observed long enough to be used for long-term analyses. Therefore, a number of indirect parameters have been proposed, with the sunspot number as the most commonly used parameter. Recently it has been suggested that climatic effects may be more directly associated with the length of the solar cycle. Whereas the magnitude of the sunspot number is only believed to be reliable back to 1750, determination of solar activity minima may be based on other types of data. A recent reconstructed series of solar cycle lengths back to 1500 gives new information about solar activity in particular before and during the Maunder Minimum. A comparison with reconstructed temperature records has revealed that the good agreement between the solar cycle length and the global temperature found for the modern instrumental temperature record is also characteristic for the total series of reconstructed temperature data. A further result is that the response of the temperature during the pre-instrumental era is the same as for the modern temperature record. This finding confirms the close association beween terrestrial temperature and solar activity measured in terms of the solar cycle length.

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