Related papers: Cyclic behavior of solar inter-network magnetic fi…
Sunspots are the most spectacular manifestation of solar magnetism, yet, 99% of the solar surface remains 'quiet' at any time of the solar cycle. The quiet sun is not void of magnetic fields, though; they are organized at smaller spatial…
The multi-scaled solar magnetic field consists of two major components: active regions (ARs) and magnetic network. Unraveling the cycle-dependent properties and interrelations of these components is crucial for understanding the evolution…
As a large-scale motion on the Sun, the meridional flow plays an important role in determining magnetic structure and strength and solar cycle. However, the meridional flow near the solar poles is still unclear. The Hinode observations show…
We have been monitoring yearly variation in the Sun's polar magnetic fields with the Solar Optical Telescope aboard {\it Hinode} to record their evolution and expected reversal near the solar maximum. All magnetic patches in the magnetic…
We present results from the analysis of Fe I 630 nm measurements of the quiet Sun taken with the spectropolarimeter of the Hinode satellite. Two data sets with noise levels of 1.2{\times}10-3 and 3{\times}10-4 are employed. We determine the…
The Sun's magnetic field varies in multiple time scales. Observations show that the minimum between cycles 24 and 25 was the second consecutive minimum which was deeper and wider than several earlier minima. Since the active regions…
We analyze Fe I 630 nm observations of the quiet Sun at disk center taken with the spectropolarimeter of the Solar Optical Telescope aboard the Hinode satellite. A significant fraction of the scanned area, including granules, turns out to…
With the unique database from Michelson Doppler Imager aboard the Solar and Heliospheric Observatory in an interval embodying solar cycle 23, the cyclic behavior of solar small-scale magnetic elements is studied. More than 13 million…
Recent observations with the HINODE satellite have found abundant horizontal magnetic fields in the internetwork quiet Sun. We compare the results on the horizontal fields with ground-based observations. We obtained 30 sec-integrated data…
We analyze a time sequence of Inter-Network (IN) magnetograms observed at the solar disk center. Speckle reconstruction techniques provide a good spatial resolution (0.5" cutoff frequency) yet maintaining a fair sensitivity (some 20G).…
We studied the radiative properties of small magnetic elements (active region faculae and the network) during the rising phase of solar cycle 23 from 1996 to 2001, determining their contrasts as a function of heliocentric angle, magnetogram…
In addition to the `facular' brightening of active regions, the quiet Sun also contains a small scale magnetic field with associated brightenings in continuum radiation. We measure this contribution of quiet regions to the Sun's brightness…
The last solar minimum was, by recent standards, unusually deep and long. We are now close to the maximum of the subsequent solar cycle, which is relatively weak. In this article we make comparisons between different global (unresolved)…
We analyzed the size, intensity, and magnetic field strength of sunspot umbrae to compare the present cycle 24 with the previous one. We used data of the Helioseismic and Magnetic Imager onboard the Solar Dynamics Observatory and selected…
Observations with the Hinode space observatory led to the discovery of predominantly horizontal magnetic fields in the photosphere of the quiet internetwork region. Here we investigate realistic numerical simulations of the surface layers…
We investigate spatio-temporal evolution of high-degree acoustic mode frequencies of the Sun and the surface magnetic activity, over the course of multiple solar cycles, to improve our understanding of the connection between the solar…
Using the data observed by the Solar Optical Telescope/Spectro-Polarimeter aboard the Hinode satellite, the horizontal and vertical fields are derived from the wavelength-integrated measures of Zeeman-induced linear and circular…
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.…
The Sun's polar magnetic fields are directly related to solar cycle variability. The strength of the polar fields at the start (minimum) of a cycle determine the subsequent amplitude of that cycle. In addition, the polar field reversals at…
Standard statistical analysis of the magnetic properties of the quiet Sun rely on simple histograms of quantities inferred from maximum-likelihood estimations. Because of the inherent degeneracies, either intrinsic or induced by the noise,…