Mendeley Climate Change Library
243
243
Jul 6, 2019
07/19
by
B. M. Jakosky; D. Brain; M. Chaffin; S. Curry; J. Deighan; J. Grebowsky; J. Halekas; F. Leblanc; R. Lillis; J. G. Luhmann; L. Andersson; N. Andre; D. Andrews; D. Baird; D. Baker; J. Bell
texts
eye 243
favorite 0
comment 0
Observations of the Mars upper atmosphere made from the Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft have been used to determine the loss rates of gas from the upper atmosphere to space for a complete Mars year (16 Nov 2014 – 3 Oct 2016). Loss rates for H and O are sufficient to remove ∼2–3 kg/s to space. By itself, this loss would be significant over the history of the planet. In addition, loss rates would have been greater early in history due to the enhanced solar EUV and...
Topics: Atmosphere, Magnetospheres, Mars, Mars atmosphere, Mars climate, Solar wind
336
336
May 29, 2011
05/11
by
Dang, Qinglai; Margolis, Hank; Coyea, Mari
texts
eye 336
favorite 0
comment 0
The Boreal Ecosystem-Atmospheric Study (BOREAS) TE-9 (Terrestrial Ecology) team collected several data sets related to chemical and photosynthetic properties of leaves in boreal forest tree species. This data set describes the relationship between photosynthetically active radiation (PAR) levels and foliage nitrogen in samples from six sites in the BOREAS Northern Study Area (NSA) collected during the three 1994 intensive field campaigns (IFCs). This information is useful for modeling the...
Topics: IO, TORUSES, SATELLITE ATMOSPHERES, SPACE OBSERVATIONS (FROM EARTH), PLANETARY MAGNETOSPHERES
291
291
May 29, 2011
05/11
by
Gatlin, G. M.; Parker, P. A.; Owens, L. R., Jr
texts
eye 291
favorite 0
comment 0
A need for low-speed, high Reynolds number test capabilities has been identified for the design and development of advanced subsonic transport high-lift systems. In support of this need, multiple investigations have been conducted in the National Transonic Facility (NTF) at the NASA Langley Research Center to develop a semi-span testing capability that will provide the low-speed, flight Reynolds number data currently unattainable using conventional sting-mounted, full-span models. Although a...
Topics: IO, TORUSES, SATELLITE ATMOSPHERES, SPACE OBSERVATIONS (FROM EARTH), PLANETARY MAGNETOSPHERES
541
541
May 26, 2011
05/11
by
Orenberg, James; Handy, Jonatha
texts
eye 541
favorite 0
comment 0
Mixtures of a Hawaiian palagonite and an iron-rich, montmorillonite clay (15.8 /- 0.4 wt% Fe as Fe2O3) were evaluated as Mars surface spectral analogs from their diffuse reflectance spectra. The presence of the 2.2 microns absorption band in the reflectance spectrum of clays and its absence in the Mars spectrum have been interpreted as indicating that highly crystalline aluminous hydroxylated clays cannot be a major mineral component of the soil on Mars. The palagonite sample used in this study...
Topics: POLAR CAPS, DISSOCIATION, MAGNETIC FIELDS, HIGH ALTITUDE, HIGH TEMPERATURE, HYDROGEN, OXYGEN,...
266
266
May 23, 2011
05/11
by
Schiff, Lewis B.; Ekaterinaris, J. A
texts
eye 266
favorite 0
comment 0
Three-dimensional Navier-Stokes numerical simulations are necessary to correctly predict the complex leeward-side flow characteristics over delta wings, including leading-edge separation, secondary separation, and vortex breakdown. This article presents Navier-Stokes solutions of subsonic vortical flow over a 75-deg sweep delta wing with a sharp leading edge. The sensitivity of the solution to the numerical scheme is examined using both a partially upwind scheme and a central-differencing...
Topics: ELECTROSTATIC PROBES, CALIBRATING, ROCKET-BORNE INSTRUMENTS, MEASURING INSTRUMENTS, THERMOSPHERE,...
Recent studies have shown that gamma-ray pulsar light curves are very sensitive to the geometry of the pulsar magnetic field. Pulsar magnetic field geometries, such as the retarded vacuum dipole and force-free magnetospheres, used to model high-energy light curves have distorted polar caps that are offset from the magnetic axis in the direction opposite to rotation. Since this effect is due to the sweepback of field lines near the light cylinder, offset polar caps are a generic property of...
Topics: NASA Technical Reports Server (NTRS), GAMMA RAYS, STELLAR MAGNETOSPHERES, PULSAR MAGNETOSPHERES,...
The application of pulsar physics to determine the magnetic structure in the planet Jupiter outer magnetosphere is discussed. A variety of theoretical models are developed to illuminate broad areas of consistency and conflict between theory and experiment. Two possible models of Jupiter's magnetosphere, a pulsar-like radial outflow model and an earth-like convection model, are examined. A compilation of the simple order of magnitude estimates derivable from the various models is provided.
Topics: NASA Technical Reports Server (NTRS), JUPITER (PLANET), PLANETARY MAGNETIC FIELDS, PLANETARY...
The objective of the proposal was to construct global magnetospheric models of Jupiter for the use of Jovian magnetospheric community. In the four years of the grant period we were able to achieve all of the stated science objectives. The work has resulted in: 1) A new structural model of Jovian current sheet; 2) Global thickness map of the current sheet; 3) Magnetic field models of the current sheet; 4) The global model of Jupiter's magnetospheric field including hinging and delay of the...
Topics: NASA Technical Reports Server (NTRS), JUPITER ATMOSPHERE, PLANETARY MAGNETOSPHERES, ATMOSPHERIC...
419
419
Jul 11, 2010
07/10
by
Weinstein, M. S
texts
eye 419
favorite 0
comment 0
Two master resolution friskets were produced on Kodak film types SO-368 and SO-242. These target masters consisted of 21 density steps with three-bar resolution targets at five modulation levels within each step. The target masters were contact printed onto Kodak separation negative film, type 4131, using both a contact printing frame and enlarger as one method of exposure, and a Miller-Holzwarth contact printer as the other exposing device. Red, green, and blue Wratten filters were used to...
Topics: DIFFUSION THEORY, ELECTRON DIFFUSION, JUPITER (PLANET), RADIATION BELTS, DIFFUSION COEFFICIENT,...
188
188
Jun 2, 2011
06/11
by
Chechulin, B. B
texts
eye 188
favorite 0
comment 0
The plastic flow during deformation of real polycrystalline metals has specific characteristics which distinguish the plastic deformation of metals from the deformation of ordinary isotropic bodies. One of these characteristics is the marked micro-nonuniformity of the plastic deformation of metals. P.O. Pashkov demonstrated the presence of a considerable micro-nonuniformity of the plastic deformation of coarse-grained steel wit medium or low carbon content. Analogous results in the case of...
Topics: ION INJECTION, PLASMAS (PHYSICS), MAGNETOSPHERES, ENERGETIC PARTICLES, EARTH MAGNETOSPHERE,...
217
217
Jun 12, 2011
06/11
by
Teo, K. B. K.; Hash, D. B.; Bell, M. S.; Chhowalla, M.; Cruden, B. A.; Amaratunga, G. A. J.; Meyyappan, M.; Milne, W. I
texts
eye 217
favorite 0
comment 0
Plasma enhanced chemical vapour deposition (PECVD) has been recently used for the production of vertically aligned carbon nanotubedfibers (CN) directly on substrates. These structures are potentially important technologically as electron field emitters (e.g. microguns, microwave amplifiers, displays), nanoelectrodes for sensors, filter media, superhydrophobic surfaces and thermal interface materials for microelectronics. A parametric study on the growth of CN grown by glow discharge dc-PECVD is...
Topics: NASA PROGRAMS, RESEARCH AND DEVELOPMENT, EXPLORER SATELLITES, HIGH ENERGY ELECTRONS, MAGNETIC...
This document is the final report for NASA Grant NAG5-4615, 'Satellie Atmosphere and Io Torus Observations', Nicholas M. Schneider, P.I., awarded to the University of Colorado, 8/l/97-3/31/00. The grant was originally awarded to Dr. Doyle T. Hall, who left the University of Colorado before the completion of the project. Io is the most volcanically active body in the solar system, and it is embedded deep within the strongest magnetosphere of any planet. This combination of circumstances leads to...
Topics: NASA Technical Reports Server (NTRS), IO, TORUSES, SATELLITE ATMOSPHERES, SPACE OBSERVATIONS (FROM...
396
396
May 30, 2011
05/11
by
Patterson-Hine, Ann; Hindson, William; Sanderfer, Dwight; Deb, Somnath; Domagala, Chuc
texts
eye 396
favorite 0
comment 0
Model-based reasoning techniques hold much promise in providing comprehensive monitoring and diagnostics capabilities for complex systems. We are exploring the use of one of these techniques, which utilizes multi-signal modeling and the TEAMS-RT real-time diagnostic engine, on the UH-60 Rotorcraft Aircrew Systems Concepts Airborne Laboratory (RASCAL) flight research aircraft. We focus on the engine and transmission systems, and acquire sensor data across the 1553 bus as well as by direct...
Topics: MERCURY (PLANET), RADIO WAVES, SPACE MISSIONS, PLASMA WAVES, SPECTRAL RESOLUTION, TEMPORAL...
289
289
Jul 25, 2010
07/10
by
Beltracchi, Todd J.; Gabriele, Gary A
texts
eye 289
favorite 0
comment 0
The method proposed for estimating sensitivity derivatives is based on the Recursive Quadratic Programming (RQP) method and in conjunction a differencing formula to produce estimates of the sensitivities. This method is compared to existing methods and is shown to be very competitive in terms of the number of function evaluations required. In terms of accuracy, the method is shown to be equivalent to a modified version of the Kuhn-Tucker method, where the Hessian of the Lagrangian is estimated...
Topics: MAGNETOHYDRODYNAMIC STABILITY, PLANETARY MAGNETOSPHERES, PLASMA WAVES, WAVE PROPAGATION, BOUNDARY...
A three-dimensional code for a rapidly rotating magnetosphere in which the MHD equations and the Maxwell equations were solved by using the two step Lax Endroff scheme, was developed. Preliminary results were presented at the Fall AGU meeting in San Francisco. The basic simulation model to study the solar wind interactions was adapted to other bodies in addition to Jupiter. Because of the recent comet flybys, a comet was chosen as the first model. The aim was to model the formation of the...
Topics: NASA Technical Reports Server (NTRS), ASTRONOMICAL MODELS, BOW WAVES, COMETARY MAGNETOSPHERES,...
355
355
May 23, 2011
05/11
by
BhanuSankaraRao, K.; Schuster, H.; Halford, G. R
texts
eye 355
favorite 0
comment 0
The damage mechanisms influencing the axial strain-controlled Low-Cycle Fatigue (LCF) behavior of alloy 800H at 850 C have been evaluated under conditions of equal tension/compression ramp rates (Fast-Fast (F-F): 4 X 10(sup -3)/s and Slow-Slow (S-S): 4 X 10(sup -5)/s) and asymmetrical ramp rates (Fast-Slow (F-S): 4 x 10(sup -3)/s / 4 X 10(sup -5/s and Slow-Fast (S-F): 4 X 10(sup -5) / 4 X 10(sup -3)/s) in tension and compression. The fatigue life, cyclic stress response, and fracture modes were...
Topics: RING CURRENTS, ELECTRIC FIELDS, STORMS, MAGNETOSPHERES, MAGNETIC STORMS, TEMPORAL DISTRIBUTION,...
206
206
May 31, 2011
05/11
by
Woods, Judy L.; West, Jeff S.; Sulyma, Peter R
texts
eye 206
favorite 0
comment 0
Lockheed Martin Space Operations - Stennis Programs (LMSO) at the John C Stennis Space Center (NASA/SSC) has designed and built a Beowulf computer cluster which is owned by NASA/SSC and operated by LMSO. The design and construction of the cluster are detailed in this paper. The cluster is currently used for Computational Fluid Dynamics (CFD) simulations. The CFD codes in use and their applications are discussed. Examples of some of the work are also presented. Performance benchmark studies have...
Topics: IO, PLANETARY MAGNETIC FIELDS, TORUSES, PLANETARY MAGNETOSPHERES, JUPITER (PLANET), FIELD ALIGNED...
301
301
Jun 2, 2011
06/11
by
Spruce, Joseph P.; Giardino, Marc
texts
eye 301
favorite 0
comment 0
Cultural resource surveys are important for compliance with Federal and State law. Stennis Space Center (SSC) in Mississippi is researching, developing, and validating remote sensing and Geographical Information System (GIS) methods for aiding cultural resource assessments on the center's own land. The suitability of IKONOS satellite imagery for georeferencing scanned historic maps is examined in this viewgraph presentation. IKONOS data can be used to map historic buildings and farmland in...
Topics: MAGNETOHYDRODYNAMICS, MAGNETOHYDRODYNAMIC FLOW, SOLAR WIND, MAGNETOSPHERES, PLASMA INTERACTIONS,...
Io is the most volcanically active body in the solar system, and it is embedded deep within the strongest magnetosphere of any planet. This combination of circumstances leads to a host of scientifically compelling phenomena, including (1) an atmosphere out of proportion with such a small object, (2) a correspondingly large atmospheric escape rate, (3) a ring of dense plasma locked in a feedback loop with the atmosphere, and (4) a host of Io-induced emissions from radio bursts to UV auroral...
Topics: NASA Technical Reports Server (NTRS), IO, TORUSES, SATELLITE ATMOSPHERES, SPACE OBSERVATIONS (FROM...
The Magnetospheric Multiscale (MMS) mission is a formation flying mission that consists of four distinct phases: phases 1 and 2 are low-inclination highly elliptical orbits (HEO), phase 3 is a double-lunar swingby which transfers phase 2 to phase 4, a high-inclination HE0 orbit. Phase 2 is designed to reach the first lunar swingby of phase 3 in the most efficient fashion. It is shown that when the orientation of the line of apsides of phase 2 is properly chosen, no extra Delta-V is required...
Topics: NASA Technical Reports Server (NTRS), LUNAR PHASES, PLANETARY MAGNETOSPHERES, ABORT TRAJECTORIES,...
Our studies elucidated the relationship between the auroral arcs and magnetotail phenomena. One paper examined particle energization in the source region of the field-aligned currents that intensify at substorm onset when the arc brightens to form the westward electrojet. A second paper examined the relationship between the precipitating particles in the arcs, the location of the westward electrojet, and magnetospheric source regions. Two earlier papers also investigated the roles that field...
Topics: NASA Technical Reports Server (NTRS), FIELD ALIGNED CURRENTS, ELECTROJETS, MAGNETIC STORMS,...
437
437
Jun 11, 2011
06/11
by
Dufrene, Warren R., Jr
texts
eye 437
favorite 0
comment 0
This paper describes the development of a planned approach for Autonomous operation of an Unmanned Aerial Vehicle (UAV). A Hybrid approach will seek to provide Knowledge Generation through the application of Artificial Intelligence (AI) and Intelligent Agents (IA) for UAV control. The applications of several different types of AI techniques for flight are explored during this research effort. The research concentration is directed to the application of different AI methods within the UAV arena....
Topics: PLASMA WAVES, POLAR CAPS, WAVE-PARTICLE INTERACTIONS, DATA PROCESSING, WINDPOWER UTILIZATION,...
The convective motion and its relation to the electric field in the magnetosphere of Jupiter are investigated. It is shown that the electric field is induced in the Jovian ionosphere due to the corotating action of the ionospheric gases and further is communicated into the magnetosphere along the magnetic lines of force which connect between the ionosphere and the magnetosphere. This electric field drives the plasma to corotate with the planet in the magnetosphere. The distribution of the...
Topics: NASA Technical Reports Server (NTRS), CONVECTION CURRENTS, ELECTRIC FIELDS, JUPITER (PLANET),...
The planned Voyager 2 Saturn mission is described. Information about Saturn obtained from the Voyager 1 encounter is summarized. Data on the satellites and rings of Saturn are tabulated. The video programming schedule for the Voyager 2 Saturn encounter is given. The Voyager science team is listed.
Topics: NASA Technical Reports Server (NTRS), MISSION PLANNING, SATURN (PLANET), VOYAGER PROJECT, PLANETARY...
We present the structure of the 3D ideal MHD pulsar magnetosphere to a radius ten times that of the light cylinder, a distance about an order of magnitude larger than any previous such numerical treatment. Its overall structure exhibits a stable, smooth, well-defined undulating current sheet which approaches the kinematic split monopole solution of Bogovalov 1999 only after a careful introduction of diffusivity even in the highest resolution simulations. It also exhibits an intriguing spiral...
Topics: NASA Technical Reports Server (NTRS), MAGNETOHYDRODYNAMICS, PULSAR MAGNETOSPHERES, CURRENT SHEETS,...
The M2P2 concept is based on the transfer of momentum from the solar wind to an artificial magnetic field structure like that naturally occurs at all magnetized planets in the Solar System, called the magnetosphere. The objectives of this program include the following: (1) Demonstrate artificial magnetospheric inflation through cold plasma filling in vacuum; (2) Demonstrate deflection of a surrogate solar wind by an artificial magnetosphere in the laboratory vacuum chamber; (3) Compare...
Topics: NASA Technical Reports Server (NTRS), MAGNETIC FIELD CONFIGURATIONS, PLASMA PROPULSION, SPACE...
500
500
May 23, 2011
05/11
by
Halford, Gary R
texts
eye 500
favorite 0
comment 0
The framework of an engineering creep-fatigue durability model has been adapted for use in estimating the radial static burst pressure and cyclic low-cycle fatigue macro-crack initiation resistance of continuous fiber reinforced (CFR) metal matrix composite (NIMC) rings for application at 800 F. Rings of circumfrentially wrapped SCS6/Ti-15-3 were manufactured by Textron Specialty Metals and burst tested by Pratt & Whitney as a part of a cooperative program with the NASA Lewis Research...
Topics: PLASMAPAUSE, ELECTROSTATIC SHIELDING, ELECTRIC FIELDS, TWILIGHT GLOW, UNIFORM FLOW, BULGING, PLASMA...
309
309
May 31, 2011
05/11
by
Grandgenett, Nea
texts
eye 309
favorite 0
comment 0
Within the context of innovative coursework and other educational activities, we are proposing the establishment of a University of Nebraska at Omaha (UNO) Center for the Use of Space Data in Teaching and Learning. This Center will provide an exciting and motivating process for educators at all levels to become involved in professional development and training which engages real life applications of mathematics, science, and technology. The Center will facilitate innovative courses (including...
Topics: NASA SPACE PROGRAMS, ELECTRONS, MAGNETOSPHERES, POSITRONS, SPACE MISSIONS, RADIATION DOSAGE,...
Topics: NASA Technical Reports Server (NTRS), ASTRONOMICAL PHOTOGRAPHY, SATURN (PLANET), VOYAGER 1...
219
219
May 23, 2011
05/11
by
Batey, Michae
texts
eye 219
favorite 0
comment 0
Clouds play an important role in the radiation budget of the atmosphere. A good understanding of how clouds interact with solar radiation is necessary when considering their effects in both general circulation models and climate models. This study examined the radiative properties of clouds in both an inhomogeneous cloud system, and a simplified cloud system through the use of a Monte Carlo model. The purpose was to become more familiar with the radiative properties of clouds, especially...
Topics: PULSARS, THERMAL EMISSION, SUPERNOVA REMNANTS, X RAY SOURCES, X RAYS, NEUTRON STARS, PULSAR...
352
352
Jul 25, 2010
07/10
by
Gibson, J. S.; Adamian, A
texts
eye 352
favorite 0
comment 0
An approximation theory is presented for the LQG (Linear-Quadratic-Gaussian) optimal control problem for flexible structures whose distributed models have bounded input and output operators. The main purpose of the theory is to guide the design of finite dimensional compensators that approximate closely the optimal compensator. The optimal LQG problem separates into an optimal linear-quadratic regulator problem and an optimal state estimation problem. The solution of the former problem lies in...
Topics: INTERPLANETARY MAGNETIC FIELDS, INTERPLANETARY MEDIUM, SOLAR WIND, SPACE PLASMAS, EXPLORER 50...
We use multi-point timing analysis to determine the orientation and motion of flux transfer events (FTEs) detected by the four Cluster spacecraft on the high-latitude dayside and flank magnetopause during 2002 and 2003. During these years, the distances between the Cluster spacecraft were greater than 1000 km, providing the tetrahedral configuration needed to select events and determine velocities. Each velocity and location will be examined in detail and compared to the velocities and...
Topics: NASA Technical Reports Server (NTRS), FLUX TRANSFER EVENTS, MOTION, MAGNETOSPHERES, CLUSTER...
An expression for the rate of energy generation by a pulsar an estimate of contribution from all the pulsars in our galaxy to the observed cosmic ray intensity was presented. The theory was then developed to an expanded version, and observational facts supporting the theory were cited.
Topics: NASA Technical Reports Server (NTRS), COSMIC RAYS, FLUX (RATE), PULSARS, RADIATION SOURCES,...
Current density determines the plasma flow regime. Cascades are non-stationary. ALWAYS. All flow regimes look different: multiple components (?) Return current regions should have particle accelerating zones in the outer magnetosphere: y-ray pulsars (?) Plasma oscillations in discharges: direct radio emission (?)
Topics: NASA Technical Reports Server (NTRS), PULSAR MAGNETOSPHERES, MAGNETOHYDRODYNAMIC FLOW, CURRENT...
Progress in research to understand the three-dimensional nature of the Europagenic plasma torus is summarized. Efforts to improve the plasma torus description near Europa's orbit have included a better understanding of Europa's orbit and an improved description of the planetary magnetic field. New plasma torus chemistry for molecular and atomic species has been introduced and implemented in Europa neutral cloud models. Preliminary three-dimensional model calculations for Europa's neutral clouds...
Topics: NASA Technical Reports Server (NTRS), JUPITER (PLANET), PLANETARY MAGNETOSPHERES, EUROPA, SPACE...
Data was obtained from the UVI imager, ground based magnetometers, incoherent scatter radars, HF radars (SuperDarn), DMSP satellites, and NOAA TIROS satellites. The data from these sources have been integrated into a consistent description of the ionosphere, using the AMIE technique.
Topics: NASA Technical Reports Server (NTRS), MAGNETOSPHERES, MAGNETOSPHERE-IONOSPHERE COUPLING,...
The purpose of this investigation was to establish the relative roles of solar wind and the internal plasma processes in shaping the structure and dynamics of Jupiter's magnetosphere. We carried out several investigations to establish these roles. Three new research papers have resulted from this work. In the following we provide brief summaries of the main findings.
Topics: NASA Technical Reports Server (NTRS), JUPITER (PLANET), GEOPHYSICS, PLANETARY MAGNETOSPHERES, SOLAR...
This grant was focused on research in two specific areas: (1) development of new techniques and software for assimilation, analysis and visualization of data from multiple satellites making in-situ measurements; and (2) determination of the role of MHD waves in energy transport during storms and substorms. Results were obtained in both areas and presented at national meetings and in publications. The talks and papers that were supported in part or fully by this grant are listed in this paper.
Topics: NASA Technical Reports Server (NTRS), ENERGY TRANSFER, MAGNETOHYDRODYNAMIC WAVES, MAGNETOSPHERES,...
Under this grant we have undertaken a series of magnetohydrodynamic (MHD) simulation and data analysis studies to help better understand the configuration and dynamics of Jupiter's magnetosphere. We approached our studies of Jupiter's magnetosphere in two ways. First we carried out a number of studies using our existing MHD code. We carried out simulation studies of Jupiter s magnetospheric boundaries and their dependence on solar wind parameters, we studied the current systems which give the...
Topics: NASA Technical Reports Server (NTRS), INTERPLANETARY MAGNETIC FIELDS, JUPITER (PLANET),...
367
367
May 29, 2011
05/11
by
Anderson, Darwin; Papagno, Andre
texts
eye 367
favorite 0
comment 0
The BOREAS TE-1 team collected various data to characterize the soil-plant systems in the BOREAS SSA. Particular emphasis was placed on nutrient biochemistry, the stores and transfers of organic carbon, and how the characteristics were related to measured methane fluxes. The overall transect in the Prince Albert National Park (Saskatchewan, Canada) included the major plant communities and related soils that occurred in that section of the boreal forest. Soil physical, chemical, and biological...
Topics: PLANETARY MAGNETOSPHERES, RUNGE-KUTTA METHOD, SATELLITE ORBITS, ENERGETIC PARTICLES, GALILEAN...
Information about the magnetosphere of Saturn is provided: the magnetic dipole moment is axisymmetric, the bow shock stand-off distance is about 22 R sub S. The satellites Titan, Dione, and Tethys are probably the primary sources of magnetospheric plasma. Outside of approx. 4 R sub S, energetic particles are energized by diffusing inward while conserving their first and second adiabatic invariants. Particles are lost by satellite sweep-out, absorption byt the E ring and probably also by plasma...
Topics: NASA Technical Reports Server (NTRS), BOW WAVES, PLANETARY MAGNETOSPHERES, SATURN (PLANET), DIONE,...
Jupiter's aurora are normally confined to limited regions around the magnetic poles. Our collected spectra show that very unusual periods of global scale auroral activity occurred during September and November of 1988. During the global scale events, the H2 and H3(+) emissions remained confined to their unusual auroral zones, but strong, unidentified emissions appeared in the vicinity of the H2 quadrupole lines. This would suggest that unusual periods of widespread magnetospheric dumping...
Topics: NASA Technical Reports Server (NTRS), AURORAL ZONES, AURORAS, IO, JUPITER (PLANET), MAGNETOSPHERES,...
A theoretical model is presented for the plasma in the Jovian magnetosphere whose pressure is comparable to the corotational energy density. The model predicts a thin current sheet of 1 Jupiter radius to 2 Jupiter radii half-thickness. The current sheet lies almost precisely in the magnetic equatorial plane and is not appreciably warped as suggested previously.
Topics: NASA Technical Reports Server (NTRS), ASTRONOMICAL MODELS, CURRENT SHEETS, JUPITER ATMOSPHERE,...
418
418
Jul 26, 2010
07/10
by
Bakhle, Milind A.; Mahajan, Aparajit J.; Keith, Theo G., Jr.; Stefko, George L
texts
eye 418
favorite 0
comment 0
Two methods for calculating linear frequency domain aerodynamic coefficients from a time marching Full Potential cascade solver are developed and verified. In the first method, the Influence Coefficient, solutions to elemental problems are superposed to obtain the solutions for a cascade in which all blades are vibrating with a constant interblade phase angle. The elemental problem consists of a single blade in the cascade oscillating while the other blades remain stationary. In the second...
Topics: MERCURY SPACECRAFT, MERCURY (PLANET), MERCURY PROJECT, PLANETARY ORBITS, SPACE EXPLORATION,...
The objective of the Twin Electric Magnetospheric Probes Exploring on Spiral Trajectories (TEMPEST) mission is to understand the nature and causes of magnetic storm conditions in the magnetosphere whether they be manifested classically in the buildup of the ring current, or (as recently discovered) by storms of relativistic electrons that cause the deep dielectric charging responsible for disabling satellites in synchronous orbit, or by the release of energy into the auroral ionosphere and the...
Topics: NASA Technical Reports Server (NTRS), NASA PROGRAMS, RESEARCH AND DEVELOPMENT, EXPLORER SATELLITES,...
We present a modification of the relativistic phase shift method of determining the radio emission geometry from pulsar magnetospheres proposed by Gangadhara & Gupta (2001). Our modification provides a method of determining radio emission altitudes which does not depend on the viewing geometry and does not require polarization measurements. We suggest application of the method to the outer edges of averaged radio pulse profiles to identify magnetic field lines associated with'the edges of...
Topics: NASA Technical Reports Server (NTRS), PULSAR MAGNETOSPHERES, RADIO EMISSION, MAGNETIC FIELDS,...
432
432
May 23, 2011
05/11
by
McKinnon, William B.; Schenk, Paul M
texts
eye 432
favorite 0
comment 0
Chains of impact craters, or catenae, have been identified in Voyager images of Callisto and Ganymede. Although these resemble in some respects secondary crater chains, the source craters and basins for the catenae cannot be identified. The best explanation is a phenomenon similar to that displayed by former comet Shoemaker-Levy 9; tidal (or other) breakup close to Jupiter followed by gradual orbital separation of the fragments and collision with a Galilean satellite on the outbound leg of the...
Topics: AURORAS, AURORAL TEMPERATURE, FIELD ALIGNED CURRENTS, JUPITER ATMOSPHERE, ULTRAVIOLET IMAGERY,...
A model of pulsar magnetospheres is described which has evolved inductively from the work of Sturrock, where the radiation is produced near the surface of a neutron star. Some of the theoretical ideas of others, particularly those of Sturrock, are discussed. The braking index n and period-pulse-width distribution of pulsars are first reinvestigated by relaxing the conventional assumption that R sub Y = R sub L, where R sub Y is the radius of the neutral points marking the transition from closed...
Topics: NASA Technical Reports Server (NTRS), ELECTROMAGNETIC RADIATION, NEUTRON STARS, PULSAR...
This viewgraph presentation reviews the prospects of extending the understanding of gamma ray pulsars, and answering the open questions left from the limited observations that are available from current observatories. There are 2 new gamma ray observatories that are either on orbit or will be shortly launched: (1) Astro-rivelatore Gamma a Immagini LEggero (AGILE), and Gamma-ray Large Area Space Telescope (GLAST). On board GLAST there will be two instruments Large Area Telescope (LAT), and GLAST...
Topics: NASA Technical Reports Server (NTRS), GAMMA RAY TELESCOPES, PULSARS, GAMMA RAY SOURCES (ASTRONOMY),...
In 1979-1981, the three USA spacecraft Pioneer 11 and Voyagers 1 and 2 discovered and explored the magnetosphere of Saturn to the limited extent possible on flyby trajectories. Considerable variation in the locations of the bow shock (BS) and magnetopause (MP) surfaces were observed in association with variable solar wind conditions and, during the Voyager 2 encounter, possible immersion in Jupiter's distant magnetic tail. The limited number of BS and MP crossings were concentrated near the...
Topics: NASA Technical Reports Server (NTRS), BOUNDARIES, PLANETARY MAGNETOSPHERES, SATURN (PLANET), BOW...
