Behavior of F2-layer parameters and solar activity indices in the 24th cycle

2021 ◽  
Vol 67 (1) ◽  
pp. 102-110
Author(s):  
A.D. Danilov
Keyword(s):  
Solar Activity ◽  
24Th Cycle ◽  
Solar Activity Indices ◽  
Activity Indices

Solar Activity Indices in the Cycles 21–23

2012 ◽  
pp. 221-228
Author(s):  
A. A. Borisov ◽  
E. A. Bruevich ◽  
I. K. Rozgacheva ◽  
G. V. Yakunina
Keyword(s):  
Solar Activity ◽  
Solar Activity Indices ◽  
Activity Indices

Phase analysis of solar activity indices using wavelet techniques

2018 ◽  
Vol 13 (S340) ◽  
pp. 165-166
Author(s):  
C. S. Seema ◽  
P. R. Prince
Keyword(s):  
Solar Activity ◽  
Extreme Ultraviolet ◽  
Low Frequency ◽  
Phase Relationship ◽  
Precise Knowledge ◽  
Frequency Components ◽  
Cross Wavelet Transform ◽  
Solar Activity Indices ◽  
Wavelet Techniques ◽  
Activity Indices

AbstractA precise knowledge of solar extreme ultraviolet (EUV) irradiance is of great importance for better understanding of Earth′s ionosphere and thermosphere. The search for an ideal solar EUV proxy is vital since the ionospheric and thermospheric models are based on the solar proxies of EUV radiation. In this study, the phase asynchrony analysis of solar EUV data with other solar activity indices during solar cycle 23 is done. The cross-wavelet transform (XWT) technique is used to reveal the phase difference between the two time series of solar indices. Analysis reveals that the phase relationship between the indices is both time and frequency dependent. The solar indices F10.7 and Mg II core-to-wing index are found to be more synchronous with solar EUV data for low frequency components.

Periodicities of solar irradiance and solar activity indices, I

Solar Physics ◽  
1990 ◽  
Vol 129 (1) ◽  
pp. 165-189 ◽  
Author(s):  
Judit Pap ◽  
W. Kent Tobiska ◽  
S. David Bouwer
Keyword(s):  
Solar Activity ◽  
Solar Irradiance ◽  
Solar Activity Indices ◽  
Activity Indices

Series of classical solar activity indices: Kislovodsk data

2007 ◽  
Vol 41 (1) ◽  
pp. 81-86 ◽  
Author(s):  
Yu. A. Nagovitsyn ◽  
V. V. Makarova ◽  
E. Yu. Nagovitsyna
Keyword(s):  
Solar Activity ◽  
Solar Activity Indices ◽  
Activity Indices

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.

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