No abstract available
Topics: NASA Technical Reports Server (NTRS), Gallagher, D. L., NASA Marshall Space Flight Center
No abstract available
Topics: NASA Technical Reports Server (NTRS), MASS SPECTROMETERS, PLASMASPHERE, MORPHOLOGY, HELIUM IONS,...
No abstract available
Topics: NASA Technical Reports Server (NTRS), HISTOGRAMS, ION DENSITY (CONCENTRATION), ION TEMPERATURE,...
Nearly 35 years ago direct observations of cold plasmaspheric ions found enhanced O(+), O(++), and even N(+) densities in the outer plasmasphere, in particular during storm recovery conditions. Enhancements were seen inside or just outside of the plasmapause at all magnetic local times. Whereas nominal O(+) concentrations were found to be 1% or less inside the plasmasphere, enhanced O(+) in the vicinity of the plasmapause was found to reach densities comparable to H(+). Enhanced ion outflow...
Topics: Alabama Univ., Comfort, R. H., Craven, P. D., Gallagher, D. L., Goldstein, J., NASA Marshall Space...
The plasmasphere is a toroidal region of cold plasma surrounding the Earth that results from ionospheric outflow and accumulation. The physics of refilling and the dynamics of this region have been studied for nearly 50-years. During that time many models have been proposed, but little has been done to test these models due to a lack of observational information. With the launch of the IMAGE Mission in March 2000 the Radio Plasma Imager has provided true field aligned density measurements that...
Topics: NASA Technical Reports Server (NTRS), PLASMASPHERE, TOROIDAL PLASMAS, EARTH IONOSPHERE, REFILLING,...
The Science Directorate at Marshall Space Flight Center (MSFC) conducts a diverse program of Internet-based science communication through a Science Roundtable process. The Roundtable includes active researchers, writers, NASA public relations staff, educators, and administrators. The Science@NASA award-winning family of Web sites features science, mathematics, and space news to inform, involve, and inspire students and the public about science. We describe here the process of producing stories,...
Topics: NASA Technical Reports Server (NTRS), NASA PROGRAMS, COMMUNICATION, INTERNETS, AEROSPACE SCIENCES,...
The IMAGE Mission extreme ultraviolet imager (EUY) observes He+ plasmaspheric ions throughout the inner magnetosphere. Limited by ionizing radiation and viewing close to the Sun, images of the He+ distribution are available every 10 minutes for many hours as the spacecraft passes through apogee in its highly elliptical orbit. As a consistent constituent at about 15%, He+ is an excellent surrogate for monitoring all of the processes that control the dynamics of plasmaspheric plasma. In...
Topics: NASA Technical Reports Server (NTRS), PLASMAS (PHYSICS), SPACE PLASMAS, EXTREME ULTRAVIOLET...
Recent observations with the ISEE-1 spacecraft have found electric field emissions in the dayside magnetiosheath whose frequency spectrum is modulated at twice the spacecraft spin period. The upper frequency cut-off in the frequency-time spectrum of the emissions has a characteristic parabola shape or festoon shape. The low frequency cutoff ranges from 100 Hz to 400 Hz, while the high frequency limit ranges from about 1 kHz to 4 kHz. The bandwidth is found to minimize for antenna orientations...
Topics: DTIC Archive, Gallagher,D L, IOWA UNIV IOWA CITY DEPT OF PHYSICS AND ASTRONOMY, *Electrostatic...
The Earth's plasmasphere is an inner part of the magneteosphere. It is located just outside the upper ionosphere located in Earth's atmosphere. It is a region of dense, cold plasma that surrounds the Earth. Although plasma is found throughout the magnetosphere, the plasmasphere usually contains the coldest plasma. Here's how it works: The upper reaches of our planet's atmosphere are exposed to ultraviolet light from the Sun, and they are ionized with electrons that are freed from neutral...
Topics: NASA Technical Reports Server (NTRS), PLASMASPHERE, ATMOSPHERIC COMPOSITION, EARTH ATMOSPHERE,...
The Space Science Laboratory (SSL) at Marshall Space Flight Center is a multiprogram facility. Scientific research is conducted in four discipline areas: earth science and applications, solar-terrestrial physics, astrophysics, and microgravity science and applications. Representatives from each of these discipline areas participate in a Laboratory computer requirements committee, which developed this document. The purpose is to establish and discuss Laboratory objectives for computing and...
Topics: NASA Technical Reports Server (NTRS), AEROSPACE SCIENCES, COMPUTER NETWORKS, COMPUTER SYSTEMS...
No abstract available
Topics: NASA Technical Reports Server (NTRS), PLASMASPHERE, EARTH ATMOSPHERE, PLASMAPAUSE, PLASMA DENSITY,...
The author has identified the following significant results. The S-190B imagery from Skylab 3 permitted the detection of higher levels of land use detail than any satellite imagery previously evaluated using manual interpretation techniques. Resolution approaches that of 1:100,000 scale infrared aircraft photography, especially regarding urban areas. Nonurban areas are less distinct.
Topics: NASA Technical Reports Server (NTRS), AGRICULTURE, CITIES, FORESTS, INDUSTRIES, LAND USE, URBAN...
The author has identified the following significant results. Temperatures in degrees Celsius were derived from PCM counts using the Pease's modified gray window technique. The Outcalt simulator was setup on the USGS computer. The input data to the model are basically meteorological and geographical in nature. The output data is presented in three matrices.
Topics: NASA Technical Reports Server (NTRS), CITIES, LAND USE, REGIONAL PLANNING, EREP, METEOROLOGY,...
No abstract available
Topics: NASA Technical Reports Server (NTRS), PLASMASPHERE, REFILLING, EARTH IONOSPHERE, THERMOSPHERE,...
The Space Physics Analysis Network (SPAN) is a computer network connecting scientific institutions throughout the United States. This network provides an avenue for timely, correlative research between investigators, in a multidisciplinary approach to space physics studies. An objective in the development of SPAN is to make available direct and simplified procedures that scientists can use, without specialized training, to exchange information over the network. Information exchanges include raw...
Topics: NASA Technical Reports Server (NTRS), COMPUTER GRAPHICS, COMPUTER NETWORKS, INFORMATION...
Spacecraft measurements of core ions on L=4-7 field-lines typically show trapped ion distributions near the magnetic equator, and frequently indicate field-aligned ion streams at higher latitudes. The nature of the transition between them may indicate both the microphysics of hot-cold plasma interactions and overall consequences for core plasma evolution. We have undertaken a statistical analysis and characterization of this interface and its relation to the equatorial region of the inner...
Topics: NASA Technical Reports Server (NTRS), ANISOTROPY, EARTH MAGNETOSPHERE, EQUATORIAL REGIONS, FLUX...
The results of a study performed to evaluate the feasibility and merits of using an electrodynamic tether for propulsion and power generation for a spacecraft in the Jovian system are presented. The environment of the Jovian system has properties which are particularly favorable for utilization of an electrodynamic tether. Specifically, the planet has a strong magnetic field and the mass of the planet dictates high orbital velocities which, when combined with the planet's rapid rotation rate,...
Topics: NASA Technical Reports Server (NTRS), EVALUATION, FEASIBILITY ANALYSIS, TETHERING, JUPITER...
The Inner Magnetosphere Imager (IMI) mission will carry instruments to globally image energetic neutral atoms, far and extreme ultraviolet light, and X-rays. These imagers will see the ring current, inner plasmasheet, plasmasphere, aurora, and geocorona. With these observations it will be possible, for the first time, to develop an understanding of the global shape of the inner magnetosphere and the interrelationships between its parts. Seven instruments are currently envisioned on a single...
Topics: NASA Technical Reports Server (NTRS), EARTH MAGNETOSPHERE, FAR ULTRAVIOLET RADIATION, IMAGING...
Thermal plasmaspheric densities and temperatures for five ion species have recently become available, even though these quantities were derived some time ago from the Retarding Ion Mass Spectrometer onboard the Dynamics Explorer 1 satellite over the years 1981-1984. The quantitative properties will be presented. Densities are found to have one behavior with lessor statistical variation below about L=2 and another with much greater variability above that Lshell. Temperatures also have a behavior...
Topics: NASA Technical Reports Server (NTRS), PLASMASPHERE, TEMPERATURE RATIO, HYDROGEN IONS, HELIUM IONS,...
The Global Core Plasma Model (GCPM) is the first empirical model for thermal inner magnetospheric plasma designed to integrate previous models and observations into a continuous in value and gradient representation of typical total densities. New information about the plasmasphere, in particular, make possible significant improvement. The IMAGE Mission Radio Plasma Imager (RPI) has obtained the first observations of total plasma densities along magnetic field lines in the plasmasphere and polar...
Topics: NASA Technical Reports Server (NTRS), PLASMASPHERE, PLASMA DENSITY, THERMAL PLASMAS, GEOMAGNETISM,...
We present initial results on the modeling of the circulation of plasmaspheric- origin plasma into the outer magnetosphere and low-latitude boundary layer (LLBL), using a dynamic global core plasma model (DGCPM). The DGCPM includes the influences of spatially and temporally varying convection and refilling processes to calculate the equatorial core plasma density distribution throughout the magnetosphere. We have developed an initial description of the electric and magnetic field structures in...
Topics: NASA Technical Reports Server (NTRS), PLASMASPHERE, PLASMAS (PHYSICS), MAGNETIC FIELD...
It is well known that the effects of EMIC waves on RC ion and RB electron dynamics strongly depend on such particle/wave characteristics as the phase-space distribution function, frequency, wave-normal angle, wave energy, and the form of wave spectral energy density. Therefore, realistic characteristics of EMIC waves should be properly determined by modeling the RC-EMIC waves evolution self-consistently. Such a selfconsistent model progressively has been developing by Khaznnov et al....
Topics: NASA Technical Reports Server (NTRS), ELECTRON SCATTERING, SELF CONSISTENT FIELDS, RING CURRENTS,...
For three decades, magnetospheric field and plasma measurements have been made by diverse instruments flown on spacecraft in many different orbits, widely separated in space and time, and under various solar and magnetospheric conditions. Scientists have used this information to piece together an intricate, yet incomplete view of the magnetosphere. A simultaneous global view, using various light wavelengths and energetic neutral atoms, could reveal exciting new data and help explain complex...
Topics: NASA Technical Reports Server (NTRS), EARTH MAGNETOSPHERE, PLASMASPHERE, IMAGE ANALYSIS, EARTH...
No abstract available
Topics: NASA Technical Reports Server (NTRS), 4eb45951c62c47fa8303668bd6460d9e, Alabama Univ.,...
No abstract available
Topics: NASA Technical Reports Server (NTRS), 32a05be17807435c964e5bb7256a48e9,...
Previous results of plasmapause position surveys have been synthesized into a description of the underlying global distribution of plasmasphere-like or core plasma densities unique to a steady state magnetosphere. Under these steady conditions, the boundary between high- and low-density regions is taken to represent the boundary between diurnal near-corotation and large-scale circulation streamlines that traverse the entire magnetosphere. Results indicate a boundary that has a pronounced bulge...
Topics: NASA Technical Reports Server (NTRS), PLASMAPAUSE, PLASMA DENSITY, PLASMASPHERE, MAGNETOSPHERES,...
With Observations from the retarding ion mass spectrometer on the Dynamics Explorer I from 1981 through 1984, we examine the He(+) to H(+) density ratios as a function of altitude, latitude, season, local time, geomagnetic and solar activity. We find that the ratios are primarily a function of geocentric distance and the solar EUV input. The ratio of the densities, when plotted as a function of geocentric distance, decrease by an order of magnitude from 1 to 4.5 R(sub E). After the He(+) to...
Topics: NASA Technical Reports Server (NTRS), HELIUM IONS, MASS SPECTROMETERS, SOLAR ACTIVITY, SOLAR...
There are no author-identified significant results in this report.
Topics: NASA Technical Reports Server (NTRS), CENTRAL ATLANTIC REGIONAL ECOL TEST SITE, DISTRICT OF...
No abstract available
Topics: NASA Technical Reports Server (NTRS), PLASMAPAUSE, CORONAL MASS EJECTION, TIME DEPENDENCE, MAGNETIC...
The Global Core Plasma Model (GCPM) is the first empirical model for thermal inner magnetospheric plasma designed to integrate previous models and observations into a continuous in value and gradient representation of typical total densities. New information about the plasmasphere, in particular, makes possible significant improvement. The IMAGE Mission Radio Plasma Imager (RPI) has obtained the first observations of total plasma densities along magnetic field lines in the plasmasphere and...
Topics: NASA Technical Reports Server (NTRS), PLASMAS (PHYSICS), ATMOSPHERIC MODELS, PLASMASPHERE, PLASMA...
It is well-known that the effects of electromagnetic ion cyclotron (EMIC) waves on ring current (RC) ion and radiation belt (RB) electron dynamics strongly depend on such particle/wave characteristics as the phase-space distribution function, frequency, wavenormal angle, wave energy, and the form of wave spectral energy density. The consequence is that accurate modeling of EMIC waves and RC particles requires robust inclusion of the interdependent dynamics of wave growth/damping, wave...
Topics: NASA Technical Reports Server (NTRS), ELECTROMAGNETIC RADIATION, ION CYCLOTRON RADIATION, RADIATION...
The Inner Magnetosphere Imager (IMI) mission will carry instruments to globally image energetic neutral atoms, far and extreme ultraviolet light, and X rays. These imagers will see the ring current inner plasmasheet, plasmasphere, aurora, and geocorona. With these observations it will be possible, for the first time, to develop an understanding of the global shape of the inner magnetosphere and the interrelationships between its parts. Seven instruments are currently envisioned on a single...
Topics: NASA Technical Reports Server (NTRS), EARTH MAGNETOSPHERE, SPACECRAFT INSTRUMENTS, INNER RADIATION...
It is very well known that the effects of electromagnetic ion cyclotron (EMIC) waves on ring current (RC) ion and radiation belt (RB) electron dynamics strongly depend on such particle/wave characteristics as the phase-space distribution function, frequency, wave-normal angle, wave energy, and the form of wave spectral energy density. The consequence is that accurate modeling of EMIC waves and RC particles requires robust inclusion of the interdependent dynamics of wave growth/damping, wave...
Topics: NASA Technical Reports Server (NTRS), ELECTROMAGNETIC RADIATION, ION CYCLOTRON RADIATION,...
We present a ray-tracing study of the propagation of Pc 3 Alfven mode waves originating at the dayside magnetopause. This study reveals interesting features of a magnetospheric filter effect for these waves. Pc 3 Alfven mode waves cannot penetrate to low Earth altitudes unless the wave frequency is below approximately 30 mHz. Configurations of the dispersion curves and the refractive index show that the gyroresonance and pseudo-cutoff introduced by the heavy ion O(+) block the waves. When the...
Topics: NASA Technical Reports Server (NTRS), FILTERS, HEAVY IONS, MAGNETOHYDRODYNAMIC WAVES, MAGNETOPAUSE,...
This paper continues presentation and discussion of the results from our new global self-consistent theoretical model of interacting ring current ions and propagating electromagnetic ion cyclotron waves [Khazanov et al., 2006]. To study the effects of electromagnetic ion cyclotron wave propagation and refraction on the wave induced ring current precipitation and heating of the thermal plasmaspheric electrons, we simulate the May 1998 storm. The main findings after a simulation can be summarized...
Topics: NASA Technical Reports Server (NTRS), ELECTRON ENERGY, ION CYCLOTRON RADIATION, MATHEMATICAL...
The sixth biennial Yosemite topical conference and the first as a Chapman Conference was held on February 3 to 6, 1986. Due to the recent changes in our perception of the dynamics of the ionospheric/magnetospheric system, it was deemed timely to bring researchers together to discuss and contrast the relative importance of solar versus terrestrial sources of magnetospheric plasma. Although the solar wind was once thought to dominate the supply of plasma in the Earth's magnetosphere, it is now...
Topics: NASA Technical Reports Server (NTRS), CONFERENCES, EARTH IONOSPHERE, EARTH MAGNETOSPHERE, PLASMAS...
Future space missions like the Jupiter Icy Moons Orbiter (JIMO) planned to orbit Callisto, Ganymede, and Europa can fully utilize a variable power radio sounder instrument. Radio sounding at 1 kHz to 10 MHz at medium power levels (10 W to kW) will provide long-range magnetospheric sounding (several Jovian radii) like those first pioneered by the radio plasma imager instrument on IMAGE at low power (less than l0 W) and much shorter distances (less than 5 R(sub E)). A radio sounder orbiting a...
Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC SOUNDING, DISTANCE, ECHOES, PLASMA FREQUENCIES,...
Previous results of plasmapause position surveys have been synthesized into a comprehensive description of the plasmapause, taken to represent the boundary between diurnal near-corotation and large-scale circulation streamlines that traverse the entire magnetosphere. The result indicates a plasmapause that has a pronounced bulge in the dusk sector, that rotates sunward and shrinks markedly as geomagnetic activity (and presumably magnetospheric convection) increase. The shape of the plasmapause...
Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC CIRCULATION, AZIMUTH, BOUNDARY LAYER PLASMAS,...
We present a ray-tracing study of the propagation of Pc 3 Alfven mode waves originating at the dayside magnetopause. This study reveals interesting features of magnetospheric filter effect for these waves. Pc 3 Alfven mode waves cannot penetrate to low Earth altitudes unless the wave frequency is below approximately 30 mHz. Configurations of the dispersion curves and the refractive index show that the gyroresonance and pseudo-cutoff introduced by the heavy ion O(+) block the waves. When the...
Topics: NASA Technical Reports Server (NTRS), RAY TRACING, MAGNETOHYDRODYNAMIC WAVES, MAGNETOPAUSE, PLASMA...
By mass, thermal plasma dominates near-earth space and strongly influences the transport of energy and mass into the earth's atmosphere. It is proposed to play an important role in modifying the strength of space weather storms by its presence in regions of magnetic reconnection in the dayside magnetopause and in the near to mid-magnetotail. Ionospheric-origin thermal plasma also represents the most significant potential loss of atmospheric mass from our planet over geological time. Knowledge...
Topics: NASA Technical Reports Server (NTRS), IMAGING TECHNIQUES, THERMAL PLASMAS, HELIUM IONS, LUNAR...
A laboratory facility for conducting a variety of experiments on single isolated dust particles of astrophysical interest levitated in an electrodynamics balance has been developed at NASA/Marshall Space Flight Center. The objective of the research is to employ this experimental technique for studies of the physical and optical properties of individual cosmic dust grains of 0.1-100 micron size in controlled pressure/temperatures environments simulating astrophysical conditions. The physical and...
Topics: NASA Technical Reports Server (NTRS), COSMIC DUST, LABORATORIES, PARTICLES, PHYSICAL PROPERTIES,...
