Search Publications
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…
Radial and latitudinal intensity gradients of galactic and anomalous cosmic rays in the outer heliosphere
McDonald, F. B.; Fujii, Z.
The basic one~@~Sdimensional transport model gives the equation, gr=CVSW/~Zrr where C is the Compton-Getting factor, VSW is the solar wind velocity and ~Zrr is thee radial diffusion coefficient. In the inner heliosphere near the ecliptic plane ~Zrr iss dominated by the parallel diffusion with transition to perpendicular diffusion at near 10 AU in …
Diffusive Particle Transport in Heliomagnetic Fields with Organized Latitudinal Components
Jokipii, J. R.; Kota, J.
We discuss the potential role the meridional component of the large-scale heliospheric magnetic field (HMF) might play in the transport of cosmic rays. The standard Archimedean spiral lines of the steady, large-scale HMF has no latitudinal component. Hence latitudinal transport of particles may occur only through particle drifts and cross-field di…
Compressive-Diffusive Acceleration of Energetic Charged Particles
Giacalone, J.; Jokipii, J. R.; Kota, J.
We discuss the phenomenon of the acceleration of charged particles in a compressing di~@usive medium and apply it to recent ACE observations in the interplanetary medium. It has been recognized that the phenomenon of di~@usive shock acceleration can readily be generalized to the case where the the shock isreplaced by a gradual change in the veloci…
Cosmic ray and solar particle composition measurements in the southern solar polar region
Sanderson, T. R.; Marsden, R. G.; Tranquille, C. +2 more
This analysis is based on energetic particle measurements covering the energy range 4-20 MeV/n recorded by the COSPIN/LET instrument on the Ulysses spacecraft. Around the end of the year 2000 the Ulysses spacecraft was above the southern polar region at less than 2.5 AU radial distance from the Sun. A preliminary analysis has shown that the abunda…