Using 17 hours of full-disk MDI Doppler data we have investigated the center-to-limb variation of the oscillatory wave spectrum of the solar photosphere. Power distributions in the khν-plane are calculated for fields of 20◦ × 20◦ on the Sun, centered at every 10◦ heliographic latitude. From the centerto-limb variation of the power in the f mode and the lowest 7 p modes we obtain information abo...

The convection layer completes the transport of energy from the nuclear furnace at the center of the sun to its radiation into space by the photosphere, but most importantly for the solar wind it sets the temporal and spatial scales for the structure of the coronal magnetic field that in turn controls the properties of the solar wind. In this tutorial review we examine the properties of the fie...

High-cadence, multiwavelength optical observations of a solar active region (NOAA 10969), obtained with the Swedish Solar Telescope, are presented. Difference imaging of white light continuum data reveals a white light brightening, 2 min in duration, linked to a co-temporal and co-spatial C2.0 flare event. The flare kernel observed in the white light images has a diameter of 300 km, thus render...

We investigate the occurrence of a coronal dimming using a combination of high resolution spectro-polarimetric, spectral and broadband images which span from the deep photosphere into the corona. These observations reinforce the belief that coronal dimmings, or transient coronal holes as they are also known, are indeed the locations of open magnetic flux in the corona resulting from the launch ...

The filamentary structure of a sunspot penumbra is believed to be magnetoconvective in origin. In the outer penumbra there is a difference in inclination of up to 30 Y40 between the magnetic fields associated with bright and dark filaments, and the latter fields plunge downward below the surface toward the edge of the spot.We have proposed that these fields are dragged downward bymagnetic pumpi...

The reliability of quiet Sun magnetic field diagnostics based on the Fe I lines at 6302 Å has been questioned by recent work. We present here the results of a thorough study of high-resolution multi-line observations taken with the new spectro-polarimeter SPINOR, comprising the 5250 and 6302 Å spectral domains. The observations were analyzed using several inversion algorithms, including Milne-E...

We study the small-scale topology of dynamical phenomena in the quiet-sun internetwork atmosphere, using short-duration Fourier analysis of high-resolution filtergram sequences to obtain statistical estimates for the co-location probability of different fine-structure elements and wave modes. In this initial paper we concentrate on the topology of shortduration Fourier amplitude maps for the ph...

Theoretically calculated power spectra are compares with observed solar p-mode velocity power spectra over a range of mode degree and frequency. The depth for the sources responsible for exciting p-modes of frequency 2.0 mHz is determined from the asymmetry of their power spectra and found to be about 800 km below the photosphere for quadrupole sources and 150 km if sources are dipole. The sour...

We present observations of a long-lived solar filament cavity with soft X-ray sources along its axis. This structure appeared above the southern polar crown polarity-inversion line for approximately three rotations during 1997 June–August, centered at a west-limb passage on approximately July 3. At the limb, the Yohkoh soft Xray data showed a bright region situated above and around the projecte...

Magnetic flux ropes (MFRs) rising buoyantly through the Sun's convection zone are thought to be subject viscous forces preventing them from coherently. Numerous studies have suggested that MFRs require a minimum twist in order remain coherent during their rise. Furthermore, even get photosphere may unable successfully emerge into corona unless they at least moderately twisted, since magnetic pr...