A5048188663- Astro and Planetary Science
- Geomagnetism and Paleomagnetism Studies
- Planetary Science and Exploration
- Ionosphere and magnetosphere dynamics
- Solar and Space Plasma Dynamics
- Space Exploration and Technology
- Astrophysics and Star Formation Studies
- Spacecraft and Cryogenic Technologies
- Atomic and Molecular Physics
- Astronomical Observations and Instrumentation
- Astronomy and Astrophysical Research
- Drilling and Well Engineering
- Geophysics and Gravity Measurements
- Earthquake Detection and Analysis
- Hydraulic Fracturing and Reservoir Analysis
- Rare-earth and actinide compounds
- Geothermal Energy Systems and Applications
- Stellar, planetary, and galactic studies
- Nuclear physics research studies
- Software Engineering Techniques and Practices
- Space Satellite Systems and Control
- Aquaculture disease management and microbiota
- Laser-induced spectroscopy and plasma
- Advanced Software Engineering Methodologies
- Ocean Acidification Effects and Responses
Natural Resources Wales
2023
Tejas Networks (India)
2022
Centre for Environment, Fisheries and Aquaculture Science
2013-2021
University of Kansas
2020
Rice University
1996-2016
University of Pittsburgh
1973
The University of Texas at Austin
1971
Oklahoma City Community College
1958
Corotation of a planetary magnetosphere with the rotation frequency planet is maintained by viscous torque exerted ion‐neutral collisions in atmosphere, this being transmitted to Birkeland currents. In steady state balances inertial drag associated production and/or outward transport magnetospheric plasma. The atmosphere requires some departure from rigid corotation, i.e., difference between average velocities ionospheric plasma and un‐ionized atmosphere. paper we calculate corotation lag as...
Two mechanisms have been proposed for solar wind particle injection at the dayside magnetospheric cusps: magnetic merging and cross-field diffusion. These two are experimentally distinguishable in that they produce different latitudinal distributions of particles penetrating to low-altitude cusp. An examination proton electron measurements obtained by AE-C satellite cusp reveals evidence both types processes. A majority events, especially more intense fluxes, best explained a model which...
This paper examines the problem of magnetic merging in a fully collisionless plasma, i.e., plasma noninteracting charged particles, explicitly avoiding fluid (MHD) approximation. The Alfven self-consistency criterion that relates density to electric and fields is shown be equivalent, when suitably generalized, stress-balance requirement discussed by Rich, Vasyliunas, Wolf. From this self-consistent field speed are obtained as functions configuration incident parameters. for equal...
Although Mercury and Mars appear to have magnetospheres of comparable size, Mercury's magnetosphere accelerates charged particles, whereas Mars' apparently does not. We propose that this difference results from the fact rapid steady‐state convection, associated particle acceleration, cannot occur in a Martian because its connection highly conducting ionosphere. Mercury, which has no ionosphere probably an insufficiently surface, can exhibit solar‐wind‐induced convection hence acceleration...
The longitudinal asymmetry of the Io plasma torus, as predicted by magnetic‐anomaly model and observed Earth‐based optical astronomy, provides a driving mechanism for corotating convection system in Jupiter's magnetosphere. Here we deduce some qualitative properties this from general equations that govern steady state (although expect time‐dependent effects may also have to be included complete description Jovian convection). appears capable providing both dominant radial transport (with...
The plasma sheet is a region of hot (∼10 7 °K) that surrounds the earth, filling distant magnetosphere and separating northern southern lobes magnetospheric tail; its origin one basic outstanding problems physics. A critical review available observations indicates source must provide roughly 10 25 –10 26 particles/s to balance known loss mechanisms operating in quiet time an adiabatic or quasi‐adiabatic (Δ E ∝ ) acceleration mechanism most observed particle energy. These constraints together...
We present results from the CAPS electron spectrometer obtained during downstream flyby of Titan on 26 December 2005, which occurred a period enhanced plasma pressure inside magnetosphere. The data show an unusual split signature with two principal intervals interest outside nominal corotation wake. Interval 1 shows direct evidence for ionospheric escape at several R T in Titan's tail. 2 complex structure, mix between and magnetospheric origin. suggest mechanism based ambipolar electric...
We have analyzed the energy-latitude dispersion of protons observed in low-altitude dayside cusp on two orbits AE-C satellite an attempt to reconstruct velocity distribution source plasma. On assumption that has form a convecting bi-Maxwellian we inferred values V/sub parallel/(field-aligned flow velocity), T/sub parallel/(temperature parallel magnetic field) and (T/sub /Tperpendicular/) n, where n is number density. The parameters are consistent with single-particle model acceleration...
There have been three Cassini encounters with the south‐pole eruptive plume of Enceladus for which Plasma Spectrometer (CAPS) had viewing in spacecraft ram direction. In each case, CAPS detected a cold dense population heavy charged particles having mass‐to‐charge ( m / q ) ratios up to maximum detectable by (∼10 4 amu/ e ). These are interpreted as singly nanometer‐sized water‐ice grains. Although they both negative and positive net charges, former greatly outnumber latter, at least range...
In this paper we describe a quantitative model of magnetically interconnected (open) magnetosphere, developed as perturbation to Voigt's closed magnetosphere with given magnetopause shape. The “interconnection” (perturbation) field is obtained solution Neumann boundary value problem, the normal component distribution condition. at required be time independent, and specified in accordance one two hypotheses: subsolar point merging hypothesis Crooker's antiparallel hypothesis. resulting open...
We investigate the sources of two different electron components in Saturn's inner magnetosphere (5 < L 12 Rs) by performing phase space density ( f v )) analyses measurements made Cassini CAPS instrument (1 eV to 28 keV). Because pitch angle distributions indicate that traditional single particle invariants gyration and bounce are not appropriate, we use a formulation isotropic invariant derived Wolf (1983) Schulz (1998) show it is similar functional form first adiabatic invariant. Our )...
The departure of the Jovian magnetosphere from rigid corotation is adequately explained by outward plasma transport at distances L ≳ 10. 5% observed in Io torus, however, too large to be accounted for simply transport. We propose local production main factor determining lag torus. calculate pick‐up current provided ionization neutral atoms and relate this produced ionosphere lag. This leads an expression giving torus as a function radial distance. Charge transfer found important process,...
We propose a mechanism whereby singly charged heavy ions from the plasmasphere are convected intermittently to dayside magnetopause, accelerated there, swept into distant tail lobes and boundary layer earthward in plasma sheet re‐enter inner magnetosphere. The outer region of is known be stripped off during periods enhancement convection electric field. These cold plasmaspheric drift toward magnetopause where they may become co‐mingled with magnetosheath either through magnetic merging or...
view Abstract Citations (64) References (32) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Jovian longitudinal control of Io-related radio emissions. Dessler, A. J. ; Hill, T. W. A theoretical model is proposed to explain the emissions by Jupiter's rotational phase. The based on hypothesis that are generated Birkeland currents flowing between Io and ionosphere. Specifically, it suggested precipitation radiation-belt electrons within a certain range...
The Cassini spacecraft flew by Titan on October 26, 2004 and December 13, 2004. In both cases it entered the ionosphere of Titan, allowing exploration its plasma environment. Using observations from Plasma Spectrometer (CAPS) magnetometer along inbound legs flybys, we examine Titan's global On occasions CAPS detected populations distinct those Kronian magnetosphere at about 1–1.5 Saturn radii moon. Closer to observed drifting ion ring distributions originating and, in addition, a corotating...
[1] The Cassini E3, E5, and E7 encounters with Enceladus probed the south polar plumes, where Ion Neutral Mass Spectrometer (INMS) measured neutral H2O molecular densities up to ∼109 cm−3. We have constructed a physical model for expected water density in based on supersonic radial outflow from one or more of surface vents. apply this possible sources vapor associated multiple jets observed visible dust plumes. Our predictions fit well INMS measurements along trajectories. is optimized by...
The model of Pontius et al. (1986) for plasma transport in a corotation‐dominated magnetosphere is modified to satisfy observational constraints introduced by Richardson and McNutt (1987). As the earlier model, small discrete flux tubes whose content differs significantly from longitudinally averaged value (transient tubes) move steadily under influence centrifugal force. We consider electric fields surrounding transient tube elliptical cross section derive expressions translational velocity...
The direction of the interplanetary magnetic field appears to have a significant effect on equilibrium size day side magnetosphere. qualitative features this are illustrated here by means simple vacuum model that ignores solar wind and ionospheric plasma densities as first approximation. This idealized produces earthward displacements subsolar magnetopause equatorward polar cusp associated with southward-turning fields about factor 2 greater than observed displacements. nonzero pressure...