Periodicities in data observed during the minimum and the rising phase of solar cycle 23; years 1996 - 1999
TL;DR: In this paper, three types of observations: the daily values of the solar radio flux at 7 frequencies, the daily international sunspot number and the daily Stanford mean solar magnetic field were processed in order to find all the periodicities hidden in the data.
read more
Abstract: Three types of observations: the daily values of the solar radio flux at 7 frequencies, the daily international sunspot number and the daily Stanford mean solar magnetic field were processed in order to find all the periodicities hidden in the data. Using a new approach to the radio data, two time series were obtained for each frequency examined, one more sensitive to spot magnetic fields, the other to large magnetic structures not connected with sunspots. Power spectrum analysis of the data was carried out separately for the minimum (540 days from 1 March 1996 to 22 August 1997) and for the rising phase (708 days from 23 August 1997 to 31 July 1999) of the solar cycle 23. The Scargle periodograms obtained, normalized for the effect of autocorrelation, show the majority of known periods and reveal a clear difference between the periodicities found in the minimum and the rising phase. We determined the rotation rate of the `active longitudes' in the rising phase as equal to 444.4 $\pm$ 4 nHz ($26\fd0 \pm 0\fd3$). The results indicate that appropriate and careful analysis of daily radio data at several frequencies allows the investigation of solar periodicities generated in different layers of the solar atmosphere by various phenomena related to the periodic emergence of diverse magnetic structures.
read more
Chat with Paper
AI Agents for this Paper
Find similar papers on Google Scholar, PubMed and Arxiv
Write a critical review of this paper
Analyze citations of this paper to find unaddressed research gaps
Citations
Solar Hysteresis Pattern and Spectral Components in TEC Time Series (GPS and TIE‐GCM) of the Quadrilaterally Coupled Geomagnetic Conjugate Low‐latitude Stations
TL;DR: In this paper , the authors compared the total electron content (TEC) of the solar cycle from the Global Positioning System (GPS) and Thermosphere-Ionosphere-Electrodynamics General Circulation Model (TIE-GCM) over the geomagnetically conjugate low-latitude stations with the particular scenario of lower atmospheric conditions over land- and sea-locked locations.
Evaluation of the intermediate-term periodicities in solar and cosmic ray activities during cycle 23
TL;DR: In this paper, the presence and temporal evolution of galactic cosmic rays (GCRs) time-series and three solar parameters, namely the daily sunspot number, the coronal green line and the 10.7 cm solar radio flux over the period 1996-2003 by the wavelet technique was investigated.
Short-Term Period Variation of Relative Sunspot Numbers
TL;DR: In this paper, the authors used wavelet transform to analyze the daily relative sunspot number series over solar cycles 10-23 and discussed the characteristics of some of the periods shorter than ~600-day.
Intermediate-term periodicities in sunspot areas during solar cycles 22 and 23
TL;DR: In this paper, the data of sunspot areas recorded at the US Air Force National Oceanic and Atmospheric Administration during solar Cycles 22 and 23 (1986 September 1 to 2007 August 31) have been analyzed to investigate the midterm periodicities.
Investigation of the Hemispheric Asymmetry in Solar Flare Index During Solar Cycle 21 – 24 from the Kandilli Observatory
TL;DR: The hemispheric asymmetry of the solar-flare index during 1976-2018 from the Kandilli Observatory is studied in this paper, where different methodologies, such as cross-correlation analysis, rescaled-range analysis, empirical mode decomposition, and date-compensated discrete Fourier transform, have been used on the hemispheres of the index and absolute asymmetry data to study various inherent characteristics.
References
Studies in astronomical time series analysis. II - Statistical aspects of spectral analysis of unevenly spaced data
TL;DR: This paper studies the reliability and efficiency of detection with the most commonly used technique, the periodogram, in the case where the observation times are unevenly spaced to retain the simple statistical behavior of the evenly spaced case.
7.9K
A 154-day periodicity in the occurrence of hard solar flares?
TL;DR: In this paper, an analysis of the temporal distribution of 139 solar flares monitored by the Gamma Ray Spectrometer aboard the Solar Maximum Mission (GMS) is reported. But, instead of being randomly distributed in time, these events have a tendency to occur in groups with a mean spacing of about 154 days (75 nHz) over the observing interval.
472
Solar Hard X-Ray Bursts
TL;DR: In this paper, the statistical properties of over 7000 hard X-ray flares detected with the Hard X-Ray Burst Spectrometer are presented including the spectrum of peak rates and the distribution of the photon number spectrum.
273
Emergence of magnetic flux on the Sun as the cause of a 158-day periodicity in sunspot areas
TL;DR: In this paper, a time-frequency analysis using the wavelet technique of sunspot areas between 1874 and 1993 was performed, which revealed a 158-day periodicity coincident with that of energetic solar flares.
168
Related Papers (5)
Solar Activity Indi,T. Ataç,Atila Özgüç,Jan Rybak +3 more
- 01 Jan 2005