Search Publications
Cosmic ray diffusion tensor throughout the heliosphere
Matthaeus, W. H.; Bieber, J. W.; Burger, R. A. +3 more
We calculate the cosmic ray diffusion tensor based on a recently developed model of magnetohydrodynamic (MHD) turbulence in the expanding solar wind. Parameters of this MHD model are tuned by using published observations from Helios, Voyager 2, and Ulysses. We present solutions of two turbulence parameter sets and derive the characteristics of the…
On the origin of Saturn's outer auroral emission
Gérard, Jean-Claude; Grodent, Denis; Radioti, Aikaterini +1 more
Ultraviolet Hubble Space Telescope images reveal a faint but distinct auroral emission equatorward of the main ring of emission of Saturn's southern polar region. This outer auroral emission is only visible near the nightside limb for the strongly tilted viewing geometry achieved in January 2004. We model the limb-brightening amplification of this…
Modeling ULF waves in a compressed dipole magnetic field
Rae, I. J.; Rankin, R.; Degeling, A. W. +2 more
This paper presents the results of a linear model for global scale magneto-hydrodynamic (MHD) waves in a compressed dipole model magnetosphere. We examine scenarios where a localized monochromatic source along the magnetopause boundary launches MHD fast mode ultralow frequency (ULF) waves into the magnetosphere, where they couple to shear Alfvén w…
Magnetic field dipolarization in the deep inner magnetosphere and its role in development of O+-rich ring current
Keika, K.; Koshiishi, H.; Matsumoto, H. +5 more
We studied magnetic field dipolarization and associated ion acceleration in the deep inner magnetosphere, using magnetic field data obtained by the magnetometer on board the Mission Demonstration Satellite 1 (MDS-1) and the energetic neutral atom (ENA) flux data obtained by the high-energy neutral analyzer imager on board the Imager for Magnetopau…
Total electron content in the Mars ionosphere: Temporal studies and dependence on solar EUV flux
Withers, Paul; Safaeinili, Ali; Brain, David A. +3 more
Total electron content (TEC) derived from radar signal distortions is a useful tool in probing the ionosphere of Mars. We consider 26 months of data from the subsurface mode of the Mars Express MARSIS instrument and confirm that the TEC dependence on solar zenith angle (SZA) approximately matches Chapman theory. After detrending this dependence, w…
Self-consistent inner magnetosphere simulation driven by a global MHD model
Tóth, G.; Welling, D.; Jordanova, V. K. +1 more
We present results from a one-way coupling between the kinetic Ring Current Atmosphere Interactions Model with Self-Consistent B field (RAM-SCB) and the Space Weather Modeling Framework (SWMF). RAM-SCB obtains plasma distribution and magnetic field at model boundaries from the Block Adaptive Tree Solar Wind Roe Upwind Scheme (BATS-R-US) magnetohyd…
Dynamics of solar wind protons reflected by the Moon
Barabash, S.; Holmström, M.; Futaana, Y. +2 more
Solar system bodies that lack a significant atmosphere and significant internal magnetic fields, such as the Moon and asteroids, have been considered passive absorbers of the solar wind. However, ion observations near the Moon by the SELENE spacecraft show that a fraction of the impacting solar wind protons are reflected by the surface of the Moon…
Evolution of low-altitude and ring current ENA emissions from a moderate magnetospheric storm: Continuous and simultaneous TWINS observations
Roelof, E.; McComas, D. J.; Brandt, P. C. +6 more
The moderate storm of 22 July 2009 is the largest measured during the extended solar minimum between December 2006 and March 2010. We present observations of this storm made by the two wide-angle imaging neutral-atom spectrometers (TWINS) mission. The TWINS mission measures energetic neutral atoms (ENAs) using sensors mounted on two separate space…
Protons in the near-lunar wake observed by the Sub-keV Atom Reflection Analyzer on board Chandrayaan-1
Barabash, S.; Holmström, M.; Futaana, Y. +7 more
Significant proton fluxes were detected in the near-wake region of the Moon by an ion mass spectrometer on board Chandrayaan-1. The energy of these nightside protons is slightly higher than the energy of the solar wind protons. The protons are detected close to the lunar equatorial plane at a 140° solar zenith angle, that is, ∼50° behind the termi…
Observations of X-ray and EUV fluxes during X-class solar flares and response of upper ionosphere
Mahajan, K. K.; Lodhi, Neelesh K.; Upadhayaya, Arun K.
Most studies dealing with solar flare effects in the upper ionosphere, where ionization is caused by EUV photons, have been based upon X-ray fluxes measured by the SOLRAD and GOES series of satellites. To check the validity of such studies, we compare simultaneous observations of GOES X-ray fluxes and SOHO EUV fluxes for 10 X-class solar flares wh…