Study of solar activity and cosmic ray modulation during solar cycle 24 in comparison to previous solar cycle

2016 ◽  
Vol 90 (12) ◽  
pp. 1333-1339 ◽  
Author(s):  
V. K. Mishra ◽  
A. P. Mishra
Keyword(s):  
Solar Activity ◽  
Solar Cycle ◽  
Cosmic Ray ◽  
Cosmic Ray Modulation ◽  
Solar Cycle 24 ◽  
Cycle 24

Solar rotational period of cosmic rays and solar activity during the maximum phase of solar cycle 24

2021 ◽  
Author(s):  
Prithvi Raj Singh ◽  
A. I. Saad Farid ◽  
Y. P. Singh ◽  
A. K. Singh ◽  
Ayman A. Aly
Keyword(s):  
Solar Activity ◽  
Solar Cycle ◽  
Cosmic Rays ◽  
Cosmic Ray ◽  
R Package ◽  
Least Square ◽  
Maximum Phase ◽  
Cosmic Ray Intensity ◽  
Solar Cycle 24 ◽  
Cycle 24

Abstract To study the solar rotational oscillation on daily averaged time series of solar activity proxies: sunspot number (SSN), modified coronal index (MCI), solar flare index (FI), and cosmic ray intensity (CRI) are subjected to Lomb/Scargle periodogram, and continuous wavelet transform. For this purpose, we have used data of all the considered parameters from 2012 to 2015, which covers the maximum phase including the polarity reversal period of the solar cycle 24. Both spectral analysis techniques are carried out to study the behavior of 27-days on the time scale of the synodic period and to follow their evolution throughout the epoch. Further, we have used R package RobPer (least square regression) techniques and obtained a significant true period ~27 days is present in this study. It is noted that the ~27-day period of solar activity parameters and cosmic rays is much prominent during the examined period.

scholarly journals Long-Term Cosmic Ray Variability and the CME-Index

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Helen Mavromichalaki ◽  
Evangelos Paouris
Keyword(s):  
Standard Deviation ◽  
Solar Cycle ◽  
Cosmic Ray ◽  
Heliospheric Current Sheet ◽  
Angular Width ◽  
Cosmic Ray Intensity ◽  
Cosmic Ray Modulation ◽  
Solar Cycle 23 ◽  
Solar Cycle 24 ◽  
Cycle 24

The cosmic ray modulation in relation to solar activity indices and heliospheric parameters during the period January 1996–October 2011, covering the solar cycle 23 and the ascending phase of solar cycle 24, is studied. The new perspective of this contribution is that the CME-index, obtained from only the CMEs with angular width greater than 30 degrees, gives much better results than in previous works. The proposed model for the calculation of the modulated cosmic ray intensity obtained from the combination of solar indices and heliospheric parameters gives a very satisfactory value of the standard deviation. The best reproduction of the cosmic ray intensity is obtained by taking into account solar and interplanetary indices such as sunspot number, interplanetary magnetic field, CME-index, and heliospheric current sheet tilt. The standard deviation between the observed and calculated values is about 6.63% for the solar cycle 23 and 4.13% for the ascending part of solar cycle 24.

Cosmic ray modulation and radiation dose of aircrews during the solar cycle 24/25

Space Weather ◽  
2017 ◽  
Vol 15 (4) ◽  
pp. 589-605 ◽  
Author(s):  
Shoko Miyake ◽  
Ryuho Kataoka ◽  
Tatsuhiko Sato
Keyword(s):  
Solar Cycle ◽  
Radiation Dose ◽  
Cosmic Ray ◽  
Cosmic Ray Modulation ◽  
Solar Cycle 24 ◽  
Cycle 24

scholarly journals MANIFESTATION OF SOLAR ACTIVITY AND DYNAMICS OF THE ATMOSPHERE IN VARIATIONS OF 577.7 AND 630.0 nm ATMOSPHERIC EMISSIONS IN SOLAR CYCLE 24

2020 ◽  
Vol 6 (3) ◽  
pp. 81-85
Author(s):  
Aleksandr Mikhalev
Keyword(s):  
Solar Activity ◽  
Solar Cycle ◽  
Atomic Oxygen ◽  
Correlation Coefficients ◽  
Atmospheric Emissions ◽  
Annual Average ◽  
Solar Cycle 24 ◽  
Cycle 24 ◽  
Activity Indices

In the paper, variations of the night emission intensities in the 557.7 and 630 nm atomic oxygen lines [OI] in 2011–2019 have been analyzed. The analysis is based on data from the ISTP SB RAS Geophysical Observatory. The emission intensities are compared with atmospheric, solar, and geophysical parameters. High correlation coefficients between monthly average and annual average 630.0 nm emission intensities and solar activity indices F10.7 have been obtained. This suggests a key role of solar activity in variations of this emission in the period of interest. Variations of the 557.7 nm emission demonstrate to a greater extent the correlations of the stratospheric zonal wind (QBO.U30 index) with quasi-biennial oscillations. The causes of the weak dependence of the 557.7 nm emission intensity on solar activity in solar cycle 24 are discussed.

Seasonal behavior of H component during solar cycle 24

2021 ◽  
Author(s):  
Yasmina Bouderba ◽  
Ener Aganou ◽  
Abdenaceur Lemgharbi
Keyword(s):  
Solar Activity ◽  
Solar Cycle ◽  
Horizontal Component ◽  
Low Latitude ◽  
Seasonal Behavior ◽  
The Earth ◽  
Earth Magnetic Field ◽  
Solar Cycle 24 ◽  
Minimum Solar Activity ◽  
Cycle 24

<p>In this work we will show the behavior of the horizontal component H of the Earth Magnetic Field (EMF) along the seasons during the period of solar cycle 24 lasting from 2009 to 2019. By means of  continuous measurements of geomagnetic components (X, Y) of the EMF, we compute the horizontal component H at the Earth’s surface. The data are recorded with a time resolution of one minute at Tamanrasset observatory in Algeria at the geographical coordinates of 22.79° North and 5.53° East. These data are available from the INTERMAGNET network. We find that the variation in amplitude of the hourly average of H component at low latitude changes from a season to another and it is greater at the maximum solar activity than at the minimum solar activity.</p><p><strong>Keywords:</strong> Solar cycle 24, Season, Horizontal component H. </p>

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

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.

Sign in / Sign up

Export Citation Format

Share Document