Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons™

Open Access. Powered by Scholars. Published by Universities.®

1995

Utah State University

Discipline
Keyword
Publication
Publication Type

Articles 121 - 124 of 124

Full-Text Articles in Physical Sciences and Mathematics

A Correlative Comparison Of The Ring Current And Auroral Electrojets Using Geomagnetic Indices, W. B. Cade Iii, Jan Josef Sojka, Lie Zhu Jan 1995

A Correlative Comparison Of The Ring Current And Auroral Electrojets Using Geomagnetic Indices, W. B. Cade Iii, Jan Josef Sojka, Lie Zhu

All Physics Faculty Publications

From a study of the 21 largest geomagnetic storms during solar cycle 21, a strong correlation is established between the ring current index Dst and the time-weighted accumulation of the 1-hour auroral electrojet indices, AE and AL. The time-weighted accumulation corresponds to convolution of the auroral electrojet indices with an exponential weighting function with an e-folding time of 9.4 hours. The weighted indices AEw and ALw have correlation coefficients against Dst ranging between 0.8 and 0.95 for 20 of the 21 storms. Correlation over the entire solar cycle 21 database is also strong but not as …

Go to article

Parameterized Ionospheric Model: A Global Ionospheric Parameterization Based On First Principles Models, R. E. Daniell Jr., L. D. Brown, D. N. Anderson, M. W. Fox, P. H. Doherty, D. T. Decker, Jan Josef Sojka, Robert W. Schunk Jan 1995

Parameterized Ionospheric Model: A Global Ionospheric Parameterization Based On First Principles Models, R. E. Daniell Jr., L. D. Brown, D. N. Anderson, M. W. Fox, P. H. Doherty, D. T. Decker, Jan Josef Sojka, Robert W. Schunk

All Physics Faculty Publications

We describe a parameterized ionospheric model (PIM), a global model of theoretical ionospheric climatology based on diurnally reproducible runs of four physics based numerical models of the ionosphere. The four numerical models, taken together, cover the E and F layers for all latitudes, longitudes, and local times. PIM consists of a semianalytic representation of diurnally reproducible runs of these models for low, moderate, and high levels of both solar and geomagnetic activity and for June and December solstice and March equinox conditions. PIM produces output in several user selectable formats including global or regional latitude/longitude grids (in either geographic or …

Go to article

What Is The Source Of Observed Annual Variations In Plasmaspheric Density?, S. M. Guiter, C. E. Rasmussen, T. I. Gombosi, Jan Josef Sojka, Robert W. Schunk Jan 1995

What Is The Source Of Observed Annual Variations In Plasmaspheric Density?, S. M. Guiter, C. E. Rasmussen, T. I. Gombosi, Jan Josef Sojka, Robert W. Schunk

All Physics Faculty Publications

Plasmaspheric densities have been observed previously to be higher in December than in June, with the ratio varying between 1.5 and 3.0 and with larger variations at lower L shells. In order to search for the cause of the observed annual variations, we have modeled plasmaspheric density, using a time-dependent hydrodynamic model. On an L = 2 field line with geomagnetic longitude equal to 300°, the modeled plasmaspheric densities were a factor of 1.5 times higher in December than in June. The modeled December to June density ratio was found to increase slightly with L shell, in contrast to observations; …

Go to article

Vibrational Dynamics And Structure Of Amorphous Carbon Modeled Using The Embedded Ring Approach, T. E. Doyle, John R. Dennison Jan 1995

Vibrational Dynamics And Structure Of Amorphous Carbon Modeled Using The Embedded Ring Approach, T. E. Doyle, John R. Dennison

All Physics Faculty Publications

The Raman spectrum of graphitic amorphous carbon (g-C) is modeled with simple classical methods, using rings as medium-range structural units. g-C provides a simple [nearly two dimensional (2D) with a single type of atom and one dominant bond type] prototypic example of a large class of continuous random network (CRN) solids where ring or cluster vibrations cannot be decoupled from the network in which they are embedded. We determined the in-plane vibrational modes of n=4, 5, 6, 7, and 8-membered symmetric, planar carbon rings using bond-stretching and bond-angle bending force constants; an additional force constant couples each ring node to …

Go to article

First Prev