Search Publications
Iron freeze-in temperatures measured by SOHO/CELIAS/CTOF
Livi, S.; Hsieh, K. C.; Wurz, P. +26 more
The CELIAS particle experiment on SOHO contains the Charge Time Of Flight (CTOF) mass spectrometer which measures the ionic and elemental composition of minor ions in the solar wind. In this paper we present iron freeze-in temperatures derived with a time resolution of 5 min. They indicate that some of the filamentary structures of the inner coron…
Particle acceleration at corotating interaction regions in the three-dimensional heliosphere
Balogh, A.; Forsyth, R. J.; Desai, M. I. +3 more
We have investigated the relationship between the energetic (~1MeV) proton intensity (J) and the magnetic compression ratio (C) measured at the trailing edges of corotating interaction regions observed at Ulysses. In general, our results show that the proton intensity was well correlated with the compression ratio, provided that the seed intensity…
First-year continuous solar EUV irradiance from SOHO by the CELIAS/SEM during 1996 solar minimum
Galvin, A. B.; Judge, D. L.; Ogawa, H. S. +2 more
The CELIAS/SEM photodiode spectrometer aboard SOHO continuously monitors the full-disk EUV solar irradiance in an 8-nm wavelength band centered at 30.4 nm (first order), and in a broad wavelength band between 0.1 and 77 nm (central order). We present the absolute solar EUV irradiances for the 1996 solar EUV minimum year at 1 AU. The uncertainty in…
Preliminary retrieval of solar wind latitude distribution from Solar Wind Anisotropies/SOHO observations
Schmidt, W.; Quemerais, E.; Bertaux, J. -L. +5 more
The Solar Wind Anisotropies (SWAN) instrument on board the SOHO spacecraft measures Lyman alpha radiation emanating mainly from neutral hydrogen gas in the solar neighborhood. This gas is part of the local interstellar cloud in which the Sun and the heliosphere are immersed. Measurements of Lyman alpha can be used to infer the local cloud characte…
A comparison of recurrent energetic ion enhancements observed at Ulysses and at 1 AU by IMP 8 and SAMPEX: Ulysses launch until following the first north polar passage
Mason, G. M.; Richardson, I. G.; Mazur, J. E.
During the Ulysses mission, the Goddard Space Flight Center instrument on IMP 8 and the University of Maryland low energy ion composition analyzer instrument on SAMPEX observed recurrent MeV/amu ion enhancements in the ecliptic plane at 1 AU. We identify those IMP 8/SAMPEX events related to the recurrent events observed at Ulysses from its launch …
Ion energy equation for the high-speed solar wind: Ulysses observations
Balogh, A.; McComas, D. J.; Goldstein, B. E. +4 more
Ulysses data in the high-speed solar wind that cover a wide range of latitudes centered on the solar poles were studied to test whether a polytrope law can be used to close the ion energy equation. Three approaches were taken. We determined the correlation between proton temperature and density (1) in the free expansion of the high-speed solar win…
Latitudinal distribution of >106MeV protons and its relation to the ambient solar wind in the inner southern and northern heliosphere: Ulysses Cosmic and Solar Particle Investigation Kiel Electron Telescope results
Sierks, H.; Kunow, H.; Bothmer, V. +12 more
We present observations and model calculations of the modulated intensities of galactic cosmic ray protons above 106 MeV/n along the Ulysses trajectory. Data are taken by the Cosmic and Solar Particle Investigation (COSPIN) Kiel Electron Telescope (KET) from spring 1993 to fall 1996. During this time period solar activity decreased and galactic co…
Ion acoustic-like waves observed by Ulysses near interplanetary shock waves in the three-dimensional heliosphere
Forsyth, R. J.; Neugebauer, M.; MacDowall, R. J. +2 more
The Ulysses spacecraft encountered 160 interplanetary shock waves between the time of its launch in October 1990 and the end of 1993 when it reached 48°S heliographic latitude. The onboard radio and plasma wave instrument observed many plasma waves associated with these shocks. Electrostatic waves at frequencies between the ion and electron plasma…
The solar energetic particle event of April 14, 1994, as a probe of shock formation and particle acceleration
Bothmer, V.; MacDowall, R. J.; Cane, H. V. +4 more
Gradual solar energetic particle (SEP) events observed at 1 AU are associated with coronal mass ejections (CME) that drive shocks which are presumed to accelerate the ions and electrons to suprathermal energies. However, high-energy (>30 MeV) proton and (>1 MeV) electron events are nearly always associated with both CMEs and flares, suggesti…
Energetic ion populations and periodicities near Jupiter
Balogh, A.; Sarris, E. T.; Anagnostopoulos, G. C. +2 more
The HISCALE experiment, during Ulysses' approach to Jupiter, observed a ~10 hour periodic softening in ion spectrum outside the plasma sheet that (1) is not related to the approach of the plasma sheet, (2) is in phase with the «clock» relativistic electron modulation, and (3) is related to flux increase at low energies (<=200 keV) and flux decr…