Related papers: Inversions for Deep Solar Meridional Flow Using Sp…
Observations of the Sun in the visible spectral range belong to standard measurements obtained by instruments both on the ground and in the space. Nowadays, both nearly continuous full-disc observations with medium resolution and dedicated…
To date, no self-consistent numerical simulation of the solar interior has succeeded in reproducing the observed thinness of the solar tachocline, and the persistence of uniform rotation beneath it. Although it is known that the uniform…
We have measured the meridional motions of the magnetic elements in the Sun's surface layers since 1996 and find systematic and substantial variations. In general the meridional flow speed is fast at cycle minima and slow at cycle maxima.…
We use global and local helioseismic inversions to explore the prevailing dynamical balances in the solar Near-Surface Shear Layer (NSSL). The differential rotation and meridional circulation are intimately linked, with a common origin in…
Meridional flow results from slight deviations from the thermal wind balance. The deviations are relatively large in the boundary layers near the top and bottom of the convection zone. Accordingly, the meridional flow attains its largest…
Helioseismology provides important constraints for the solar dynamo problem. However, the basic properties and even the depth of the dynamo process, which operates also in other stars, are unknown. Most of the dynamo models suggest that the…
We investigate whether the Babcock-Leighton flux-transport dynamo model remains in agreement with observations if the meridional flow profile is taken from helioseismic inversions. Additionally, we investigate the effect of the loss of…
We analyze a solar active region observed by the Hinode CaII H line using the time-distance helioseismology technique, and infer wave-speed perturbation structures and flow fields beneath the active region with a high spatial resolution.…
Compared to quasi-steady-state corona models that are constrained by a time-invariant magnetogram over a CR period, time-evolving corona models driven by time-varying photospheric magnetograms are more realistic and can maintain more useful…
The properties of the solar wind, as measured in situ throughout the heliosphere, depend both on the characteristics of its coronal source and on the intrinsic processes governing its interplanetary evolution. Recently, radial and Parker…
Ring diagram analysis of solar oscillation power spectra obtained from MDI data is carried out to study the velocity fields in the outer part of the solar convection zone. The three dimensional power spectra are fitted to a model which has…
Information on the rotation rate of the corona, and its variation over latitude and solar cycle, is valuable for making global connections between the corona and the Sun, for global estimates of reconnection rates, and as a basic parameter…
Using time-distance helioseismic measurements of meridional flow in the near-surface shear layer over a period of 14 years, starting from May 2010, we probe the depth structure and evolution of its cross-equatorial part. We confirm that the…
We have measured zonal and meridional components of subsurface flows up to a depth of 30 Mm below the solar surface by applying the technique of ring diagram on Dopplergrams which are constructed from the spherical harmonic (SH)…
Surges are cool and dense ejections typically observed in chromospheric lines and closely related to other solar phenomena like UV bursts or coronal jets. Our aim is to address the current lack of inverted models and diagnostics of surges…
We present the assessment of a diffusion-dominated mean field axisymmetric dynamo model in reproducing historical solar activity and forecast for solar cycle 25. Previous studies point to the Sun's polar magnetic field as an important proxy…
Determining accurate and precise stellar ages is a major problem in astrophysics. These determinations are either obtained through empirical relations or model-dependent approaches. Currently, seismic modelling is one of the best ways of…
Coronal seismology is a diagnostic tool used in solar physics for measuring parameters that are otherwise hard to measure; of these parameters, magnetic field values are arguably the most important. The parameters are inferred by combining…
This paper investigates the influence of Earth's dipole tilt angle on the reverse convection cells (sometimes referred to as lobe cells) in the Northern Hemisphere ionosphere during northward IMF, which we relate to high-latitude…
In the outer envelope of the Sun and in other stars, differential rotation and meridional circulation are maintained via the redistribution of momentum and energy by convective motions. In order to properly capture such processes in a…