相关论文: Estimate of Solar Maximum using the 1-8 \AA$\,$Geo…
In this article, we report an evidence of very high and statistically significant relationship between hemispheric asymmetry in solar coronal rotation rate and solar activity. Our approach is based on cross correlation of hemispheric…
We report on the variability of rotation periods of solar coronal layers with respect to temperature (or, height). For this purpose, we have used the observations from Atmospheric Imaging Assembly (AIA) telescope on board Solar Dynamics…
The solar soft X-ray observations from the GOES satellites provide one of the best quantitative records of solar activity, with nearly continuous flare records since 1975. We present a uniform analysis of the entire time series for 1975 to…
Sunspot Cycle 25 over 3 years past the cycle minimum of December 2019. At this point, curve-fitting becomes reliable and consistently indicates a maximum sunspot number of 135+/-10 - slightly larger than Cycle 24's maximum of 116.4, but…
The solar cycle onset at mid-latitudes, the slow down of the sunspot drift toward the equator, the tail-like attachment and the overlap of successive cycles at the time of activity minimum are delicate issues in $\alpha\Omega$ dynamo wave…
Solar coronal holes are sources of high-speed solar wind streams, which cause persistent geomagnetic activity especially at high latitudes. Here we estimate seasonal solar wind speeds at 1 AU for the last 100 years using high-latitude…
The Geostationary Operational Environmental Satellite (GOES) solar soft X-ray (SXR) irradiance in the 1-8{\AA} wavelength range is a long-standing measure of solar activity, used to define the classification of flare strengths. As a result,…
Solar variability occurs over a broad range of spatial and temporal scales, from the Sun's brightening over its lifetime to the fluctuations commonly associated with magnetic activity over minutes to years. The latter activity includes most…
Aims: To investigate solar polar fields during cycle 24, using measurements of solar magnetic fields in the latitude range 55 - 90 degree and 78 - 90 degree, to report a prolonged and unusual hemispheric asymmetry in the polar field…
The solar X-ray irradiance is significantly heightened during the course of a solar flare, which can cause radio blackouts due to ionization of the atoms in the ionosphere. As the duration of a solar flare is not related to the size of that…
In the previous study (Hiremath 2006a), the solar cycle is modeled as a forced and damped harmonic oscillator and from all the 22 cycles (1755-1996), long-term amplitudes, frequencies, phases and decay factor are obtained. Using these…
Properties of the Sun's interior can be determined accurately from helioseismological measurements of solar oscillations. These measurements, however, are in conflict with photospheric elemental abundances derived using 3-D hydrodynamic…
The Sun's activity cycle governs the radiation, particle and magnetic flux in the heliosphere creating hazardous space weather. Decadal-scale variations define space climate and force the Earth's atmosphere. However, predicting the solar…
Context. We present the first high-cadence multi-wavelength radial-velocity observations of the Sun-as-a-star, carried out during 57 consecutive days using the stellar \'echelle spectrograph at the Hertzsprung SONG Telescope operating at…
Verified and updated calibrated absolute solar flux in the He II 30.4 nm spectral band-pass as measured by the Solar EUV Monitor (SEM) allows us to study variations of the solar EUV irradiance near the minima of Solar Cycles 22/23 and…
The light curves of solar flares in the impulsive phase are complex in general, indicating that multiple physical processes are involved in. With the GOES (Geostationary Operational Environmental Satellite) observations, we find that there…
The Solar Diameter Monitor measured the duration of solar meridian transits during the 6 years 1981 to 1987, spanning the declining half of solar cycle 21. We have combined these photoelectric measurements with models of the solar…
Research efforts that require observations of high solar activity, such as multiwavelength studies of large solar flares and CMEs, must contend with the 11-year solar cycle to a degree unparalleled by other segments of heliophysics. While…
Context. The relation between solar surface rotation and sunspot activity still remains open. Sunspot activity has dramatically reduced in solar cycle 24 and several solar activity indices and flux measurements experienced unprecedentedly…
The concept of degree of similarity ({\eta}) is proposed to quantitatively describe the similarity of a parameter (e.g. the maximum amplitude Rmax) of a solar cycle relative to a referenced one, and the prediction method of similar cycles…