Search Publications
The Interstellar H Flow: Updated Analysis of SOHO/SWAN Data
Bertaux, Jean-Loup; Lallement, Rosine; Lamy, Philippe +4 more
We update two kinds of results obtained with the SWAN instrument on board SOHO. First, we use H cell data recorded in 2001 and derive the H flow direction in the same way the study was done at solar minimum. We again compare with the Helium flow direction and doing so correct for the coordinate system change between the Ulysses and SOHO missions. …
Heliospheric Energetic Particle Reservoirs: Ulysses and ACE 175-315 keV Electron Observations
Lario, D.
Heliospheric energetic particle reservoirs are usually observed in the decay phase of large solar energetic particle (SEP) events when particle intensities measured by widely separated spacecraft (in longitude, latitude and radial distance) present comparable intensities (within a factor of 2-3) that evolve similarly in time. We use near-relativis…
Ulysses Observations of the Properties of Multiple Ion Beams in the Solar Wind
Goldstein, B. E.; Neugebauer, M.; Zhou, X. -Y.
Properties of multiple ion beams in the solar wind beyond 1 AU as observed by the SWOOPS experiment on Ulysses are discussed. The solar wind proton distributions are approximated by a two beam bi-Maxwellian model. The slower outward traveling beam typically comprises the majority of the solar wind density. Differential streaming between the slower…
Role of latitude of source region in Solar Energetic Particle events
Dalla, S.; Agueda, N.
Solar Energetic Particle (SEP) measurements from the Ulysses spacecraft have shown that the latitudinal separation between the parent solar flare and the nominal footpoint of the detecting spacecraft is an important parameter in ordering characteristics of the observed time-intensity profiles during SEP events. In this study, we consider data from…
Transient Phenomena in the Distant Solar Wind and in the Heliosheath
McComas, D. J.; Pogorelov, N. V.; Burlaga, L. F. +6 more
The difference in the heliocentric distances at which the Voyager 1 and Voyager 2 spacecraft crossed the termination shock (TS) is likely due to a combination of the heliospheric asymmetry caused by the interstellar magnetic field (ISMF) and time-dependent boundary conditions at the Sun. We analyze both effects numerically. It is shown that an inc…
Velocity Distributions and Proton Beam Production in the Solar Wind
Voitenko, Yuriy; Pierrard, Viviane
Helios, Ulysses, and Wind spacecraft have observed the velocity distribution functions (VDFs) of solar wind particles deviating significantly from Maxwellians. We review recent models using different approximations and mechanisms that determine various observed characteristics of the VDFs for the electrons, protons and minor ions. A new generation…
Solar Wind Speed And Temperature Relationship
Matthaeus, William H.; McComas, David J.; Henney, Carl J. +1 more
Previous studies of solar wind proton temperature and speed have found a break in the curve between 400 and 550 km/s. Examining all the OMNI 2 data from 1965 to 2009, we create plots binned in both temperature and speed in order to identify where the majority of the points lie. Using yearly color plots to evaluate the curve shape we find most of t…
Quasi-thermal noise spectroscopy: preliminary comparison between kappa and sum of two Maxwellian distributions
Issautier, K.; Zouganelis, I.; Moncuquet, M. +3 more
Quasi-thermal noise spectroscopy has been intensively used to measure in situ the solar wind electron density and core temperature in space with various spacecraft. This method allowed study of the large-scale properties of the solar wind. This paper reminds theoretical tools to compute the quasi-thermal noise spectroscopy using a superposition of…
Composition Of The Inner Source Measured With The Solar Wind Ion Composition Spectrometer On Ulysses
Geiss, J.; Gloeckler, G.; Fisk, L. A.
To explain the unexpected discovery of C+, the existence of an inner source of pickup ions close to the Sun was proposed. We report on detailed analyses of the composition and the radial and latitudinal variations of inner source pickup ions measured with the Solar Wind Ion Composition Spectrometer on Ulysses from 1991 to 1998, approach…
Spectral anisotropy of solar wind turbulence in the inertial range and dissipation range
Podesta, J. J.
Wavelet analysis is a tool that can simultaneously analyze spacecraft data in both time and frequency. This enables the magnetic energy spectrum (trace spectrum) to be measured for different angles between the local mean magnetic field B0 and the direction of the mean flow within a single data set. Examples obtained around solar minimum…