Search Publications
First results from UVCS/SOHO
Romoli, M.; Raymond, J. C.; Naletto, G. +20 more
We present here the first results obtained by the Ultraviolet Coronagraph Spectrometer (UVCS) operating on board the SOHO satellite. The UVCS started to observe the extended corona at the end of January 1996; it routinely obtains coronal spectra in the 1145 A˚ - 1287 A˚, 984 A˚ - 1080 A˚ ranges, and intensity data in the visible continuum. Through…
The modelling of the latitude dependence of cosmic ray protons and electrons in the inner heliosphere
Potgieter, M. S.; Heber, B.; Ferrando, P. +1 more
Observations during the fast latitude scan of Ulysses show that the latitude dependence of cosmic ray protons is significantly less than predicted by drift models which were based on the Parker geometry for the heliospheric magnetic field (HMF) and diffusion coefficients ~ 1/B_p. Recent modeling with a modified HMF and enhanced turbulence in the p…
ULYSSES observations of intermittent heliospheric turbulence
Balogh, A.; Horbury, T. S.; Forsyth, R. J. +1 more
Structure function measurements of small scale magnetic field fluctuations in high speed streams emanating from the Sun's polar coronal holes are well described by a multifractal model of intermittent turbulence. We discuss structure functions and present measurements of intermittency through the transition regime - encompassing scales between wav…
SATI: a spectral airglow temperature imager
Rodrigo, R.; Wiens, R. H.; Moise, A. +6 more
An empirical understanding of planetary scale perturbations in the upper atmosphere is most effectively gained by the complementary use of both satellite and ground-based instrumentation. Limb observations from space provide vertical information and broad global coverage, while ground-based observations provide detailed system development in both …
Measurements of H I and O VI velocity distributions in the extended solar corona with UVCS/SOHO and UVCS/Spartan 201
Romoli, M.; Raymond, J. C.; Naletto, G. +23 more
The Ultraviolet Coronagraph Spectrometer on the Solar and Heliospheric Observatory, UVCS/SOHO, and the Ultraviolet Coronal Spectrometer on the Spartan 201 satellite, UVCS/Spartan, have been used to measure H I 1215.67 A˚ line profiles in polar coronal holes of the Sun at projected heliocentric heights between 1.5 and 3.0 R_solar. UVCS/SOHO also me…
MeV to GeV electron propagation and modulation: results of the KET-telescope onboard ULYSSES
Ferrando, P.
The KET instrument onboard Ulysses is continuously monitoring the flux of MeV to GeV electrons. I summarize here the main results obtained with data from the ~ 7 MeV and > 300 MeV electron KET channels, collected from launch up to the end of 1995 after completion of the Ulysses prime mission. Regarding low energy electrons, the stress is put on…
The heliospheric modulation of galactic cosmic rays at solar minimum
Potgieter, M. S.
The observations acquired by the Ulysses spacecraft since launch, but especially during the recent fast latitude scan, have provided a comprehensive, 3-dimensional view of the inner heliosphere. Together with the observations by IMP 8, Pioneer 10 and the two Voyagers, a wealth of new observations on particles and fields enables us to improve signi…
Radial and azimuthal components of the heliospheric magnetic field: ulysses observations
Forsyth, R.; Balogh, A.; Burton, M. E. +2 more
Two invariants associated with the Parker model of the solar wind involve the radial, B_R, and azimuthal, B_T, components of the heliospheric magnetic field. These invariants have been investigated using Ulysses data obtained at high latitudes in both the north and south solar hemispheres. The magnetic flux invariant, r^2B_R, is essentially indepe…
The dust sensor for CASSINI
Grün, Eberhard; Srama, Ralf
In October 1997 a unique mission to the Saturnian system will be launched by NASA, the CASSINI mission. One goal of this mission is to study the Saturnian dust environment, and for this task, the COSMIC DUST ANALYZER (CDA) has been developed and is currently under test. Impact ionization is used to determine the speed (1 - 100 km/s) and the mass (…
Merging 4 spacecraft data: concepts used for analysing discontinuities
Glassmeier, K. -H.; Dunlop, M. W.; Southwood, D. J. +2 more
Shocks and discontinuities in space plasmas have received much attention in both theoretical studies and spacecraft data analyses. The advent of multi-spacecraft missions, such as ISEE, have provided for a vast improvement of experimental information available on these structures. The ESA CLUSTER, multi-spacecraft mission presents the community wi…