相关论文: Time Variation of the Solar Tachocline

The frequency, $\nu_{\rm max}$, at which the envelope of pulsation power peaks for solar-like oscillators is an important quantity in asteroseismology. We measure $\nu_{\rm max}$ for the Sun using 25 years of Sun-as-a-Star Doppler velocity…

Torsional oscillations represent bands of fast and slow zonal flows around the Sun, which extend deep into the convection zone and migrate during solar cycles towards the equator following the sunspot butterfly diagram. Analysis of…

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…

We measure the axisymmetric transport of magnetic flux on the Sun by cross-correlating narrow strips of data from line-of-sight magnetograms obtained at a 96-minute cadence by the MDI instrument on the ESA/NASA SOHO spacecraft and then…

We have analyzed the full set of SOHO/MDI f- and p-mode oscillation frequencies from 1996 to date in a search for evidence of solar radius evolution during the rising phase of the current activity cycle. Like Antia et al. (2000), we find…

We present a nonlinear mean-field model of the solar interior dynamics and dynamo, which reproduces the observed cyclic variations of the global magnetic field of the Sun, as well as the differential rotation and meridional circulation.…

It has been known that some solar activity indicators show a double-peak feature in their evolution through a solar cycle, which is not conspicuous in sunspot number. In this letter, we investigate the high solar dynamic activity in the…

We study the asymmetric distribution of weak photospheric magnetic field values in the two hemispheres separately using synoptic maps from SDO/HMI, SOLIS/VSM and WSO during solar cycles 21-24. We calculate the weak-field asymmetry (shift)…

In this letter, we explore the relationship between the solar seismic radius and total solar irradiance (TSI) during last two solar cycles using the uninterrupted data from space-borne instruments onboard {\it SoHO} and {\it SDO}. The…

Small cyclic variations in the frequencies of acoustic modes are expected to be a common phenomenon in solar-like pulsators, as a result of stellar magnetic activity cycles. The frequency variations observed throughout the solar and stellar…

We study the response of the low-degree solar p-mode frequencies to the unusual extension of the minimum of solar surface activity since 2007. Helioseismic observations collected by the space-based, Sun-as-a-star GOLF instrument and by the…

Our basic theoretical understanding of the sources of cosmic rays and their propagation through the interstellar medium is hindered by the Sun, that through the solar wind affects the observed cosmic-ray spectra. This effect is known as…

The aim of this paper is to investigate whether there are any 11-yr or quasi-biennial solar cycle-related variations in solar rotational splitting frequencies of low-degree solar p modes. Although no 11-yr signals were observed, variations…

We present observations of the extended solar cycle activity in white-light coronagraphs, and compare them with the more familiar features seen in the Fe XIV green-line corona. We show that the coronal activity zones seen in the emission…

We present solar low-degree rotational splitting values based on a new analysis of Sun-as-a-star observations from the Birmingham Solar Oscillations Network, covering a 16,425-day period from 1976 December 31--2021 December 20 with a duty…

Magnetic cycles of solar-like stars influence their internal physics. Thus, the frequency, amplitude, excitation rate, and damping of the acoustic oscillation modes (p-modes) vary with the cycle over time. We need to understand the impact…

Systematic studies of the rotation rate of sunspot groups using white-light images yield controversial results on the variations of the rotation rate: sunspot groups were found to either accelerate or decelerate systematically. This…

We report on the state of the corona over the minimum and ascending phases of Solar Cycle (SC) 25 on the basis of the temporal evolutions of its radiance and of the properties of coronal mass ejections (CMEs) as determined from white-light…

The prediction of the strength of future solar cycles is of interest because of its practical significance for space weather and as a test of our theoretical understanding of the solar cycle. The Babcock-Leighton mechanism allows…

In previous work, we have shown that recent updated standard solar models cannot reproduce the radial profile of the sound speed at the base of the convective zone (CZ) and fail to predict the Li7 depletion. In parallel, helioseismology has…