We present new quantitative measurements of magnetic fields on the quiet Sun. The object was (a) to measure magnetic field strengths, and (b) to test the “kilogauss model,” which posits that the apparently weak fields are actually subtelescopic knots of kilogauss fields with small filling factors. We used a new arrangement we call the spectro-videomagnetograph (SPVMG), which applies the videoma...

The main objective of the SunFlare project is modelling and understanding the couplings between the sub-surface layers and visible layers of the Sun: the solar photosphere, chromosphere and corona. – The mass density is much larger in the subsurface layers than in the visible layers. The kinetic and magnetic energy densities are also correspondingly large. The motions that occur in these layers...

Using high-resolution ring analysis (HRRA) we deduce subsurface flows within magnetic active regions and within quiet sun. With this procedure we are capable of measuring flows with a horizontal spatial resolution of 2◦ in heliographic angle (or roughly 20 Mm). From the resulting flow fields we deduce mean inflow rates into active regions, mean circulation speeds around active regions, and prob...

We introduce a ‘‘structure minimization’’ technique to resolve the azimuthal ambiguity of 180 , intrinsic in solar vector magnetic field measurements. We resolve the 180 ambiguity by minimizing the inhomogeneities of the magnetic field strength perpendicular to the magnetic field vector. This relates to a minimization of the sheath currents that envelope the solar magnetic flux tubes, thus allo...

A potentially useful instrument for the biological sciences would be a dimensional force microscope DFM for measurement of di mensional viscous and elastic elds at sub micrometer scale in vitro and in vivo Substantial development has been conducted on various as pects of this problem but a general instrument having this capability does not yet exist All approaches I know of utilize a microscopi...

Bipolar magnetic active regions are the largest concentrations of magnetic flux on the Sun. In this paper, the properties of active regions are investigated in terms of the dynamics of magnetic flux tubes which emerge from the base of the solar convection zone, where the solar cycle dynamo is believed to operate, to the photosphere. Flux tube dynamics are computed with the ‘‘thin flux tube’’ ap...

The evolution of the solar interior is actively studied theoretically, numerically, and observationally. Many recent advancements in our understanding of the structure and dynamics of the sun have been made by studying solar oscillation. This is the science of helioseismology. Through groundand satellite-based telescopes, oscillations on the solar surface are being observed and, through appropr...

The Hanle e†ect concerns the modiÐcation of polarized resonance-line scattering by magnetic Ðelds ; thus, it can be used as a diagnostic of stellar magnetic Ðelds. The Hanle e†ect has been used to determine the Ðeld strength and distribution of magnetic structures present in prominences of the Sun. To investigate its potential use in stellar astronomy, the simpliÐed case of an optically thin ax...

We report in this letter our analysis of a large sample of photospheric vector magnetic field measurements. Our sample consists of 17200 vector magnetograms obtained from January 1997 to August 2004 by Huairou Solar Observing Station of the Chinese National Astronomical Observatory. Two physical quantities, α and current helicity, are calculated and their signs and amplitudes are studied in a s...

The Zeeman pattern of Mn I lines is sensitive to hyperfine structure (HFS) and, because of this reason, they respond to hG magnetic field strengths differently from the lines commonly used in solar magnetometry. This peculiarity has been employed to measure magnetic field strengths in quiet Sun regions. However, the methods applied so far assume the magnetic field to be constant in the resoluti...