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Energetic Particle Observations by the Cassini Spacecraft during Its Heliospheric Cruise to Saturn
Livi, S.; Dougherty, M. K.; Lario, D. +3 more
We present energetic particle observations performed by the Cassini spacecraft during its heliospheric cruise to Saturn. We cover three years of data (20002002) during the maximum of the solar cycle 23. Cassini's helio centric radial distance ranged from 2.5 to 8.0 AU. Energetic particle intensity enhancements at these distances are associated wit…
Cosmic Ray Drifts at Solar Maximum
Ferreira, S. E. S.; Potgieter, M. S.; Heber, B.
A fully time-dep endent cosmic ray modulation model, based on the numerical solution of Parker's transport equation, is used to study the amount of particle drifts needed to explain the observed 2.5 GV electron to proton ratio (e/p) by the KET instrument on the Ulysses spacecraft. It is shown that the model successfully simulates the modulation of…
Conditional Statistics of Magnetic Turbulence and the Lateral Transport of Solar Energetic Particles
Matthaeus, W. H.; Ruffolo, D.; Chuychai, Piyanate
The transport of energetic particles perpendicular to the mean magnetic field in space plasmas long has been viewed as a diffusive process. However, there is an apparent conflict between recent observations of solar energetic particles (SEP): 1) SEP from impulsive solar flares can exhibit "drop outs" in which the intensity near Earth repeatedly di…
Perpendicular Diffusion and Drift of Solar Energetic Particles in Heliospheric Magnetic Fields
McKibben, R. B.; Zhang, Ming; Jokipii, J. R.
We present evidence for large perpendicular diffusive flows of solar energetic particles. Using anisotropy measurements of 40-90 MeV protons from the July 14th, 2000 event obtained by HET on Ulysses, we find periods of first order anisotropy directed at significant angles to the local magnetic field, which can only be satisfactorily explained by p…
Populating the inner heliosphere (<5 AU) with heavy ions
Lanzerotti, L. J.; Maclennan, C. G.; Hawkins, S. E.
Heavy ion (Z > 2) and electron measurements were made on the ACE (1 AU) and Ulysses (3.2 AU) spacecraft in the inner heliosphere during the July 14, 2000 solar events. Following the last interplanetary shock event at ∼1437 UT on July 15, the heavy ion fluxes at 1 AU began to decay with an e-folding decay time for both O and Fe ions (0.5-1 MeV/n…
The Cosmic Ray Radial and Latitudinal Intensity Gradients in the Inner and Outer Heliosphere 1996-2001.3
Kunow, H.; Muller-Mellin, R.; Wibberenz, G. +7 more
The spatial intensity gradients of 150-380 MeV/n galactic cosmic ray He and 30-60 MeV/n H and He are studied over the 1996-2001.3 time period using data from the Goddard MED experiment on IMP 8, the COSPIN/KET telescope on Ulysses and the CRS experiment on Voyagers 1 and 2. This combination provides information on the radial intensity gradients in…
ULYSSES COSPIN observations of the energy and charge dependence of the propagation of solar energetic particles to the Sun's south polar regions
Kunow, H.; Heber, B.; McKibben, R. B. +12 more
We present a first report of energetic charged particle observations at latitudes above 70° S from the COSPIN instruments on Ulysses during Ulysses' recently completed pass over the Sun's south polar regions. Solar energetic particles dominated the particle flux during most of the pass, and for > 30 MeV protons there was a close correspondence …
Recurrent Depressions of Galactic Cosmic Rays in CIRs: 22-Year Cycle
Jokipii, J. R.; Kota, J.
Recurrent variations in the galactic cosmic-ray flux are produced by the interplay of diffusion and particle drifts. The enhanced scattering and consequent small diffusion in the compressed field of Corotating Interaction Regions (CIRs) causes recurrent cosmic-ray depressions at the passage of CIRs. Drift effects are primarily controlled by the st…
Latitudinal gradients and charge sign dependent modulation of galactic cosmic rays
Kunow, H.; Wibberenz, G.; Ferreira, S. E. S. +7 more
Ulysses, launched in October 1990, began its second out-of-ecliptic orbit in September 1997 and its second fast latitude scan in November 2000. At the time of the submission (May 2001) the spacecraft was located close to the heliographic equator at a radial distance of 1.3 AU. In contrast to the first orbit with the Sun declining to low activity, …
On the determination of the gamma-ray contribution in the 3-10 MeV KET electron channel along the Ulysses trajectory
Fichtner, H.; Kunow, H.; Ferreira, S. E. S. +6 more
Since the first Jovian fly-by of Pioneer 10 in 1973, it has been established that Jupiter's magnetosphere is a powerful accelerator of electrons up to several tens of MeV, which are released into interplanetary space. Measurements from Pioneer, Voyager and from spacecraft near Earth, e.g. IMP, indicate that the Jovian electron flux exceeds the gal…