distribution of magnetic fields in the quiet-sun internetwork areas has been affected by weak polarization (in particular stokes q and u) signals. to improve the signal-to-noise ratio (snr) of the weak polarization signals, several approaches, including temporal integrations, have been proposed in the literature. in this study, we aim to investigate a proper temporal-integration time with which...

Distribution of magnetic fields in the quiet-Sun internetwork areas has been affected by weak polarization (in particular Stokes Q and U) signals. To improve the signal-to-noise ratio (SNR) of the weak polarization signals, several approaches, including temporal integrations, have been proposed in the literature. In this study, we aim to investigate a proper temporal-integration time with which...

High resolution G-band images of the interior of a supergranulation cell show ubiquitous Bright Points (some 0.3 BPs per Mm2). They are located in intergranular lanes and often form chains of elongated blobs whose smallest dimension is at the resolution limit (135 km on the Sun). Most of them live for a few minutes, having peak intensities from 0.8 to 1.8 times the mean photospheric intensity. ...

We seek to clarify the nature of running penumbral (RP) waves: are they chromospheric trans-sunspot waves or a visual pattern of upward-propagating waves? Full Stokes spectropolarimetric time series of the photospheric Si i 10827 Å line and the chromospheric He i 10830 Å multiplet were inverted using a MilneEddington atmosphere. Spatial pixels were paired between the outer umbral/inner penumbra...

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 of the Sun with respect to horizontal magnetic fields and compute the corresponding polarimetric response in the Fe I 630 nm line pair. We find a local maximu...

We report two-dimensional MHD simulations which demonstrate that photospheric 5-min oscillations can leak into the chromosphere inside small-scale vertical magnetic flux tubes. The results of our numerical experiments are compatible with those inferred from simultaneous spectropolarimetric observations of the photosphere and chromosphere obtained with the Tenerife Infrared Polarimeter (TIP) at ...

The force-free parameter α, also known as helicity parameter or twist parameter, bears the same sign as the magnetic helicity under some restrictive conditions. The single global value of α for a whole active region gives the degree of twist per unit axial length. We investigate the effect of polarimetric noise on the calculation of global α value and magnetic energy of an analytical bipole. Th...

We employ the magnetic and velocity fields from turbulent dynamo simulations to synthesize the polarization of a typical photospheric line. The synthetic Stokes profiles have properties in common with those observed in the quiet Sun. The simulated magnetograms present a level of signal similar to that of the Inter-Network regions. Asymmetric Stokes V profiles with two, three and more lobes appe...

We present the first simultaneous infrared (IR) and visible spectro-polarimetric observations of a solar internetwork region. The Fe I lines at λ6301.5 Å, λ6302.5 Å, λ15648 Å, and λ15652 Å were observed, with a lag of only 1 min, using highly sensitive spectro-polarimeters operated in two different telescopes (VTT and THEMIS at the Observatorio del Teide). Some 30% of the observed region shows ...

Observations suggest that magnetic fields at the solar photosphere may be structured below the limit of the present resolution. We argue that numerical simulations could be used in a complementary way to observations in order to study the small-scale structure of photospheric fields. We present a number of illustrative examples. Subject headings: convection — MHD — Sun: magnetic fields — Sun: p...