Search Publications
Hydrogen atom lifetimes in the three-dimensional heliosphere over the solar cycle
Pryor, Wayne R.; Ajello, Joseph M.; Tobiska, W. Kent +2 more
The three-dimensional (3-D) structure of the heliosphere is investigated using in situ and remote sensing measurements. The 3-D structure of both neutral interplanetary gas and solar wind ions are affected by the solar latitude variation of the solar radiation fields (solar wind and solar EUV). Neutral hydrogen atom lifetimes against charge-exchan…
Hubble Space Telescope observations of sulfur ions in the Io plasma torus: New constraints on the plasma distribution
Schneider, Nicholas M.; Hendrix, Amanda R.; Herbert, Floyd +1 more
During the Io plasma torus crossings by the Galileo spacecraft in late 1999 and early 2000 we observed the dawn ansa of the torus using the Hubble Space Telescope (HST). Here we analyze 74 FUV HST/Space Telescope Imaging Spectrograph observations (1150 ≤ λ ≤ 1720 Å) of the dawn ansa of the Io plasma torus made during Galileo's C23, I24, and I27 to…
Tail lobe convection observed by Cluster/EDI
Nakamura, R.; Baumjohann, W.; Noda, H. +7 more
By using drift velocity data measured in the near-Earth tail lobe by the Electron Drift Instrument aboard the Cluster spacecraft, we study the average tail lobe convection of the Earth's magnetosphere. The data confirm the convection pattern toward the neutral sheet in the meridional (XZ) plane. By dividing the data according to the IMF clock angl…
Near-source and remote observations of kilometric continuum radiation from multispacecraft observations
Gurnett, D. A.; Pickett, J. S.; Menietti, J. D. +2 more
Kilometric continuum (KC) radiation was first identified from Geotail plasma wave observations. Past authors have shown that this emission has a frequency range that overlaps that of the auroral kilometric radiation (AKR) but is characterized by a fine structure of narrow-bandwidth, linear features that have nearly constant or drifting frequency. …
Toward a self-consistent treatment of the cyclotron wave heating and acceleration of the solar wind plasma
Laitinen, T.; Fichtner, H.; Vainio, R.
We have developed a steady state two-fluid description of the radial solar wind expansion close to the coronal base. The model is formulated self-consistently with respect to the radial evolution of turbulence by supplementing the moment equations of the plasma with an equation describing the radial evolution of the Alfvén wave power as originally…
Solar cycle dependence of interplanetary Lyman α emission and solar wind anisotropies derived from NOZOMI/UVS and SOHO/SWAN observations
Bertaux, Jean-Loup; Lallement, Rosine; Taguchi, Makoto +5 more
We have investigated the distributions of neutral interplanetary hydrogen Lyman α emission and their solar cycle dependence from observations with the ultraviolet imaging spectrometer (UVS) onboard the NOZOMI spacecraft and the solar wind anisotropy instrument (SWAN) onboard the solar and heliospheric observatory (SOHO) spacecraft. The SOHO/SWAN o…
A possible way of understanding the differential motion of minor ions in the solar wind
Tu, C. -Y.; Marsch, E.; Wang, L. -H.
Measurements with Solar and Heliospheric Observatory (SOHO)/Charge, Element, and Isotope Analysis System (CELIAS) in high-speed solar wind show that some minor ions such as O6+ have a relatively high drift velocity; however, other ions such as Fe9+ tend to lag behind oxygen by a few tens of km/s [, 1998]. This subtle observat…
Ion isotropy and ion resonant waves in the solar wind: Corrected Cassini observations
Gurnett, D. A.; Dougherty, M. K.; Hospodarsky, G. B. +3 more
In an earlier paper [, 2001], observations of electric field fluctuations in the range 0.5 to 25 Hz were reported. We have recently found that the data presented in that paper are seriously contaminated by broadband interference which appears to be generated in the spacecraft wake. Wake instabilities have been found by others, but the plasma condi…
Fine structure of the diamagnetic cavity boundary in comet Halley
Neubauer, F. M.; Gombosi, T. I.; Israelevich, P. L. +2 more
We calculated the electric current density in the diamagnetic cavity boundary layer (DCBL) using magnetic field data obtained during the Giotto mission to comet Halley. This current possesses both the component perpendicular to the local magnetic field and the parallel component. The perpendicular current is responsible for the screening of the di…
Role of low-frequency modes in organizing the inner heliosphere
Kunow, H.; Heber, B.; Lanzerotti, Louis J. +2 more
Cosmic ray proton data (125 to >2000 MeV) measured in the inner three-dimensional (3-D) heliosphere over the years from 1993 into 2000 by the KET instrument on the Ulysses spacecraft are examined. The data are parameterized and characterized by fitting products of spherical harmonic and sinusoidal frequency functions to three individual proton …