Chromospheric heating above supergranular boundaries

A geometrical optics technique developed in order to study energy transport by weak fast-mode hydromagnetic shock waves in a non-homogeneous, anisotropic medium has been applied to the problem of the heating of the chromosphere in the regions of intensified magnetic field which occur above the boundaries of supergranular cells. The results of the calculation indicate that there should be a temperature enhancement in the regions of the chromospheric network. This temperature enhancement is advanced as a possible mechanism for the origin of the observed calcium emission network.Publications of the Goethe Link Observatory, Indiana University, No. 106.Presently at Los Alamos Scientific Laboratories, Los Alamos, New Mexico.     

A large-scale pattern in the solar magnetic field

A clearly evident large-scale pattern in the interplanetary magnetic field during 1964 is used to search for a similar large-scale pattern in the solar magnetic field. It is found that such a pattern did exist in the photospheric field observations on both sides of the equator over a range of at least 40°N to 35°S. The pattern is basically similar at all these latitudes, and differs from that to be expected from solar differential rotation in three important respects. It is found that the solar magnetic pattern changed at all latitudes investigated within an interval of a few solar rotations.     

Diagenetic sulfate reduction in marine sediments

The importance of interstitial pore water as a vehicle for transport of dissolved ions between sediment at depth and the overlying ocean reservoir may be overestimated. The major cause of this overestimation is the assumption that the rate of ionic diffusion through the sediment is of a similar magnitude to the rate of reaction occurring within the sediment column. Examples are given to indicate that the above assumption may not be correct, at least for diagenetic sulfate reduction. Closed-system modeling, although approximate, is shown to be consistent, both qualitatively and isotopically, with measured changes that are observed for several sedimentary environments.     

Meteor44 Video Meteor Photometry

Meteor44 is a software system developed at MSFC for the calibration and analysis of video meteor data. The photometric range of the (8 bit) video data is extended from a visual magnitude range of from 8 to 3 to from 8 to −8 for both meteors and stellar images using saturation compensation. Camera and lens specific saturation compensation coefficients are derived from artificial variable star laboratory measurements. Saturation compensation significantly increases the number of meteors with measured intensity and improves the estimation of meteoroid mass distribution. Astrometry is automated to determine each image's plate coefficient using appropriate star catalogs. The images are simultaneously intensity calibrated from the contained stars to determine the photon sensitivity and the saturation level referenced above the atmosphere. The camera's spectral response is used to compensate for stellar color index and typical meteor spectra in order to report meteor light curves in traditional visual magnitude units. Recent efforts include improved camera calibration procedures and long focal length "streak" meteor photometry. Meteor44 has been used to analyze data from the 2001, 2002 and 2003 MSFC Leonid observational campaigns as well as several lesser showers.