Physical Sciences and Mathematics Commons^™

A Multi-Ion, Flux-Corrected Transport Based Hydrodynamic Model For The Plasmasphere Refilling Problem, Kausik Chatterjee, Robert W. Schunk

All Physics Faculty Publications

The objective of this paper is the application of a newly-developed Flux-Corrected Transport (FCT) based hydrodynamic solution methodology to the plasmasphere refilling problem following a geomagnetic storm. The FCT method is extremely well-suited to the solution of nonlinear partial differential equations with shocks and discontinuities. In this solution methodology, every ion species is modeled as two separate fluids originating from the northern and southern hemispheres. We present refilling results that includes three ion (H⁺, He⁺ and O⁺) species and two neutrals (H and O). We believe that with additional modifications, the model …

Observations Of The Vertical Ion Drift In The Equatorial Ionosphere During The Solar Minimum Period Of 2009, R. A. Stoneback, R. A. Heelis, A. G. Burrell, W. R. Coley, Bela G. Fejer, E. Pacheco

Bela G. Fejer

[1] The extended solar minimum conditions in 2008 and 2009 presented an opportunity to investigate the ionosphere at lower solar activity levels than previously observed. The Coupled Ion Neutral Dynamics Investigation (CINDI) Ion Velocity Meter (IVM) instrument onboard the Communication/Navigation Outage Forecasting System is used to construct the median meridional (vertical) ion drifts, ion densities, and O+ concentrations during periods of low geomagnetic activity for four characteristic seasons each year spanning late 2008 to 2010. The presence of a large semidiurnal component in the ion drift variation at the equator produced significant differences from typical ionospheric conditions. Instead of upward …

The Lunar Tide In The Equatorial F Region Vertical Ion Drift Velocity, R. J. Stening, Bela G. Fejer

Bela G. Fejer

Vertical ion drift velocity data from Jicamarca have been analyzed for a lunar semidiurnal tide using a least squares fitting method. Amplitudes of up to 6 m s−1 are obtained with phases in agreement with lunar tidal determinations of other associated physical parameters. Variations between season, solar activity, and day to night are also examined. Generally, amplitudes are larger in the southern summer. Much of the phase variation with season is very similar for solar maximum and minimum years. There is a summer to winter phase change that is most distinct at solar maximum nighttime. A day-to-night phase reversal can …

Ion Composition Of The Topside Equatorial Ionosphere During Solar Minimum, S. A. Gonzales, Bela G. Fejer, R. A. Heelis, W. B. Hanson

Bela G. Fejer

We have used observations from both the Bennett ion mass spectrometer and the retarding potential analyzer on board the Atmosphere Explorer E satellite to study the longitudinally averaged O+, H+, and He+ concentrations from 150 to 1100 km in the equatorial ionosphere during the 1975–1976 solar minimum. Our results suggest that the ion mass spectrometer measurements need to be increased by a factor of 2.15 to agree with the densities from the retarding potential analyzer and with ground-based measurements. The peak H+ concentrations are about 2.5×104 cm−3 during the day and 104 cm−3 at night and vary little with season. …

Ion Cyclotron Waves As Apossible Source Of Resonant Auroral Radar Echoes, Bela G. Fejer, R. W. Reed, D. T. Farley, W. E. Swartz, M. C. Kelley

Bela G. Fejer

Auroral backscatter radar observations were made from Ithaca, New York, at 50 MHz during the early morning of April 1, 1976, a period of high magnetic disturbance (Kp ∼ 8). The backscattered power showed large rapid (time scale of a few minutes or less) variations, characteristic of discrete radar aurora, from L = 3.5–4. Doppler spectra of waves propagating in nearly the north-south direction from up to 28 different ranges were obtained simultaneously with good spatial (7.5 km) and temporal (2 s) resolution. Some unusual spectra with very narrow peaks at Doppler shifts between about 70 and 90 Hz were …

The Photochemical Reduction Of Octacyanomolybdate(V) Ion In Aqueous Solutions, Gordon W. Gray

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The photochemical reactions occurring in aqueous solutions of octacyanomolybdate(V) ion, Mo(CN)₈^3-, during irradiation with light of 365 and 436 nm wavelengths were studied. The quantum yields and reaction products were determined for neutral, unbuffered solutions as well as solutions buffered at pH 4.0, 7.0, and 9.0.

The results of these studies showed that the Mo(CN)₈^3- ion is rapidly reduced by light to a Mo(IV) complex. In neutral or acidic media, the initial photoreduction product was found to be the red heptacyanoaquomolybdate(IV) ion, Mo(CN)₇(H₂O)^3-. Photolysis in basic solution gave the …

Differentiation Between The Ph Effect And The Bicarbonate Ion Effect In Causing Lime-Induced Chlorosis, Hyrum Del Var Petersen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Lime-induced chlorosis has been recognized for many years as a problem where plants are grown on calcareous soils. There are many factors associated with and influencing this form of iron chlorosis and because of this it has been very difficult to determine the relationship between the factors and chlorosis.

Effect Of Bicarbonate Ion And Root Aeration On Lime-Induced Chlorosis, Willard L. Lindsay

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Chlorosis in plants has been recognized as a devastating disease for over one-hundred and fifty years. It is easily recognized by a yellowing of the plant foilage and is associated with a reduced chlorophyll synthesis.

Chlorosis is found so frequently on calcareous soils that its cause is attributed at least in part to this soil factor. It is therefore referred to as lime-induced chlorosis. This type of chlorosis has become a serious problem, especially in many of the fruit-growing regions of Europe and the Western United States where the soils are calcareous. In Utah the disease is more destructive than …