An analysis of a long duration solar burst with radio flux and sunspot number

2021 ◽  
Author(s):  
W. M. A. W. Ismail ◽  
Z. S. Hamidi ◽  
N. N. M. Shariff
Keyword(s):  
Sunspot Number ◽  
Radio Flux ◽  
Solar Burst ◽  
Long Duration

scholarly journals Sunspot observations by Hisako Koyama: 1945–1996

2019 ◽  
Vol 492 (3) ◽  
pp. 4513-4527 ◽  
Author(s):  
Hisashi Hayakawa ◽  
Frédéric Clette ◽  
Toshihiro Horaguchi ◽  
Tomoya Iju ◽  
Delores J Knipp ◽  
...  
Keyword(s):  
Sunspot Number ◽  
Digital Data ◽  
Future Research ◽  
Number Series ◽  
Long Duration ◽  
Baseline Shift ◽  
Group Sunspot Number ◽  
Primary Reference ◽  
Comprehensive Recovery

ABSTRACT Sunspot records are the only observational tracer of solar activity that provides a fundamental, multicentury reference. Its homogeneity has been largely maintained with a succession of long-duration visual observers. In this article, we examine observations of one of the primary reference sunspot observers, Hisako Koyama. By consulting original archives of the National Museum of Nature and Science of Japan (hereafter, NMNS), we retrace the main steps of her solar-observing career, from 1945 to 1996. We also present the reconstruction of a full digital data base of her sunspot observations at the NMNS, with her original drawings and logbooks. Here, we extend the availability of her observational data from 1947–1984 to 1945–1996. Comparisons with the international sunspot number (Version 2) and with the group sunspot number series show a good global stability of Koyama's observations, with only temporary fluctuations over the main interval 1947–1982. Identifying drawings made by alternate observers throughout the series, we find that a single downward baseline shift in the record coincides with the partial contribution of replacement observers mostly after 1983. We determine the correction factor to bring the second part (1983–1996) to the same scale with Koyama's main interval (1947–1982). We find a downward jump by 9 per cent after 1983, which then remains stable until 1995. Overall, the high quality of Koyama's observations with her life-long dedication leaves a lasting legacy of this exceptional personal achievement. With this comprehensive recovery, we now make the totality of this legacy directly accessible and exploitable for future research.

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

2018 ◽  
Vol 30 ◽  
pp. 5-15
Author(s):  
Mohamed Semeida ◽  
Sara Khodairy ◽  
Mahmoud El Hadidy ◽  
Rabab Abdel Hamed ◽  
Shahinaz Youssef ◽  
...  
Keyword(s):  
Solar Activity ◽  
Solar Cycle ◽  
Sunspot Number ◽  
Seismic Activity ◽  
Solar Proton ◽  
Inverse Relation ◽  
Direct Relation ◽  
Radio Flux ◽  
Solar Cycle 23 ◽  
The Relationship

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.

Phase Relationship Between Sunspot Number, Flare Index and Solar Radio Flux

2012 ◽  
Vol 33 (4) ◽  
pp. 387-397 ◽  
Author(s):  
X. L. Yan ◽  
L. H. Deng ◽  
Z. Q. Qu ◽  
C. L. Xu ◽  
D. F. Kong
Keyword(s):  
Sunspot Number ◽  
Solar Radio ◽  
Phase Relationship ◽  
Radio Flux ◽  
Solar Radio Flux ◽  
Flare Index

Extreme ultraviolet line intensities from the Sun

1973 ◽  
Vol 332 (1590) ◽  
pp. 291-309 ◽  
Keyword(s):  
Sunspot Number ◽  
Extreme Ultraviolet ◽  
Solar Observatory ◽  
Absolute Calibration ◽  
The Sun ◽  
Radio Flux ◽  
Line Intensities ◽  
University College London ◽  
The Mean ◽  
Ultraviolet Spectrometer

Anextreme ultraviolet spectrometer experiment by University College London for observation of whole-Sun spectrum -line fluxes, and flown on Orbiting Solar Observatory-6, is described. Results for the four lines with absolute calibration, are show n for the first 6 months of flight, from August 1969 to February 1970. The mean fluxes for the 30.4, 53.7, 58.4 and 121.6 nm lines are 8.1 x 10 9 ± 35 % ph cm-2 s-1 , 3.2 x 10 8 + 40% ph cm -2 s-1 , 2 .5 x 10 9 + 40% ph cm -2 s-1 , and 3 x 10 11 ± 50% ph cm -2 s -1 respectively. Relations between these fluxes and the 10.7 cm radio flux and Zurich sunspot number are presented.

The LDE-Type Flare Occurrence (1969-1993)

1994 ◽  
Vol 144 ◽  
pp. 279-282
Author(s):  
A. Antalová
Keyword(s):  
Time Series ◽  
Fourier Analysis ◽  
Sunspot Cycle ◽  
List Type ◽  
Type Number ◽  
Solar Cycles ◽  
Type Iv ◽  
Long Duration ◽  
Cycle Maximum ◽  
Flare Index

AbstractThe occurrence of LDE-type flares in the last three cycles has been investigated. The Fourier analysis spectrum was calculated for the time series of the LDE-type flare occurrence during the 20-th, the 21-st and the rising part of the 22-nd cycle. LDE-type flares (Long Duration Events in SXR) are associated with the interplanetary protons (SEP and STIP as well), energized coronal archs and radio type IV emission. Generally, in all the cycles considered, LDE-type flares mainly originated during a 6-year interval of the respective cycle (2 years before and 4 years after the sunspot cycle maximum). The following significant periodicities were found:• in the 20-th cycle: 1.4, 2.1, 2.9, 4.0, 10.7 and 54.2 of month,• in the 21-st cycle: 1.2, 1.6, 2.8, 4.9, 7.8 and 44.5 of month,• in the 22-nd cycle, till March 1992: 1.4, 1.8, 2.4, 7.2, 8.7, 11.8 and 29.1 of month,• in all interval (1969-1992):a)the longer periodicities: 232.1, 121.1 (the dominant at 10.1 of year), 80.7, 61.9 and 25.6 of month,b)the shorter periodicities: 4.7, 5.0, 6.8, 7.9, 9.1, 15.8 and 20.4 of month.Fourier analysis of the LDE-type flare index (FI) yields significant peaks at 2.3 - 2.9 months and 4.2 - 4.9 months. These short periodicities correspond remarkably in the all three last solar cycles. The larger periodicities are different in respective cycles.

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