Related papers: Coronal magnetic field evolution over the cycle 24
The polar field reversal is a crucial process in the cyclic evolution of the large-scale magnetic field of the Sun.Various important characteristics of a solar cycle, such as its duration and strength, and also the cycle predictability, are…
Magnetic flux emergence and decay in the Sun span from days to months. However, their tracking is typically limited to about half a solar rotation when relying on single-vantage-point observations. Combining observations from both the…
Solar inter-network magnetic field is the weakest component of solar magnetism, but contributes most of the solar surface magnetic flux. The study on its origin has been constrained by the inadequate tempo-spatial resolution and sensitivity…
Solar activity can be witnessed in the form of sunspots and active regions, where the magnetic field is enhanced by up to a factor 1000 as compared to that of the quiet Sun. In addition, solar activity manifests itself in terms of flares,…
Knowledge regarding the coronal magnetic field is important for the understanding of many phenomena, like flares and coronal mass ejections. Because of the low plasma beta in the solar corona the coronal magnetic field is often assumed to…
The solar photosphere is filled by a magnetic field which is tangled on scales much smaller than the resolution capability of solar telescopes. This hidden magnetic field can be investigated via the Hanle effect. In 2007 we started a…
We perform a numerical parameter study to determine what effect varying differential rotation and flux emergence has on a star's non-potential coronal magnetic field. In particular we consider the effects on the star's surface magnetic…
Recent advances have made it possible to obtain two-dimensional line-of-sight magnetic field maps of the solar corona from spectropolarimetric observations of the Fe XIII 1075 nm forbidden coronal emission line. Together with the linear…
Solar magnetic fields are closely related to various physical phenomena on the sun, which can be extrapolated with different models from photospheric magnetograms. However, the Open Flux Problem (OFP), the underestimation of the magnetic…
Modeling the interface region between solar photosphere and corona is challenging, because the relative importance of magnetic and plasma forces change by several orders of magnitude. While the solar corona can be modeled by the force-free…
Measuring the global magnetic field of the solar corona remains exceptionally challenging. The fine-scale density structures observed in white light images taken during Total Solar Eclipses (TSEs) are currently the best proxy for inferring…
The Coronal Global Evolutionary Model (CGEM) provides data-driven simulations of the magnetic field in the solar corona to better understand the build-up of magnetic energy that leads to eruptive events. The CGEM project has developed six…
Thirty-four years of WSO (Wilcox Solar Observatory) and thirteen years of SOHO/MDI (Michelson Doppler Imager on the Solar and Heliospheric Observatory) magnetograms have been studied to measure the east-west inclination angle, indicating…
The magnetic field governs the corona; hence it is a crucial parameter to measure. Unfortunately, existing techniques for estimating its strength are limited by strong assumptions and limitations. These techniques include photospheric or…
Multiscale topological complexity of solar magnetic field is among the primary factors controlling energy release in the corona, including associated processes in the photospheric and chromospheric boundaries. We present a new approach for…
Context: Solar magnetic fields are regularly extrapolated into the corona starting from photospheric magnetic measurements that can suffer from significant uncertainties. Aims: Here we study how inaccuracies introduced into the maps of the…
Sunspots are obvious observable manifestations of the toroidal magnetic field generated through the dynamo in the convection zone. They appear in different sizes, having a wide distribution in their area. We analyse the sunspot group area…
Models for the evolution of the solar coronal magnetic field are vital for understanding solar activity, yet the best measurements of magnetic field lie at the photosphere, necessitating the development of coronal models which are…
The evolution of the global solar magnetic field directly impacts the interplanetary magnetic field (IMF). During the solar maximum of Cycle 24, the monthly averaged IMF strength doubled over five Carrington rotations in late 2014. To…
Aims. We show how the build-up of magnetic gradients in the Sun's corona may be inferred directly from photospheric velocity data. This enables computation of magnetic connectivity measures such as the squashing factor without recourse to…