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The radial gradient of galactic cosmic rays: Ulysses KET and ACE CRIS Measurements
Kunow, H.; Mewaldt, R. A.; Gieseler, J. +6 more
We study the spatial gradients of galactic cosmic rays in the inner heliosphere using data from the Kiel Electron Telescope (KET) aboard Ulysses and the Cosmic Ray Isotope Spectrometer (CRIS) aboard the Advanced Composition Explorer (ACE) for the time period from 1997 to 2007. This covers the solar minimum in the A>0-solar magnetic epoch, the s…
Modulation of Proton Fluxes at ~5 AU during the Largest SEP Events of 2005
Heber, Bernd; Klassen, Andreas; Struminsky, Alexei +1 more
The Ulysses spacecraft was close to the ecliptic at ~5 AU during the periods of enhanced solar activity in January and September 2005. The KET/Ulysses instrument registers a flux of cosmic ray protons within 5-2000 MeV, fluxes have been disturbed more than three solar rotations during the considered period. We find two periods of 27 days, when dis…
Observations of the December 2006 Particle Events at High Latitudes with the KET aboard Ulysses
Malandraki, O.; Heber, B.; Gomez-Herrero, R. +8 more
An unexpected rise of solar activity close to its minimum in December 2006 resulted in four X-class flares and four energetic particle events. These events were observed close to Earth and above 70 degree South by the Ulysses spacecraft, which was at a heliocentric distance of 2.8 AU at that time. Three out of these four events produced significan…
Electron anisotropies in the inner heliosphere
Ferreira, S. E. S.; Potgieter, M. S.; Nkosi, G. S.
The COSPIN/KET experiment on board the Ulysses spacecraft has been observing the flux of 3-30 MeV and also higher energy electrons in the inner heliosphere (radial distances > 5.2 AU) since its launch in 1990. These observations have indicated the presence of low-energy electrons with a strong anisotropy off the equatorial plane as far as 2.2 A…
Recurrent Modulation of Jovian Electron intensities: Ulysses KET measurements
Kunow, H.; Heber, B.; Müller-Mellin, R. +6 more
Corotating Interaction Regions are regions in the heliosphere that are formed at the leading edges of high-speed solar wind streams originating in coronal holes. Their effects on the propagation of energetic particles are known. Here we concentrate on the modulation of Jovian electrons by CIRs observed with the Kiel Electron Telescope. After its l…
Particle observations and propagation in the Three-Dimensional Heliosphere
Lario, D.; Forsyth, R. J.; Lanzerotti, L. J. +9 more
Ulysses, the first spacecraft ever to fly over the poles of the Sun, plays a central role in the Heliospheric Network, the international fleet of spacecraft to explore the Sun and Heliosphere. In November 2006, Ulysses, began its passage over the Sun’s south pole for the third time. Although like during the first polar passes in 1994/1995 the Sun …
The Effect of a Latitudinal Dependent Solar Wind Speed on Cosmic-Ray Modulation in a Fisk-type Heliospheric Magnetic Field
Burger, R. A.; Hitge, M.
The Fisk-model for the heliospheric magnetic field (HMF) was developed in an attempt to connect the structure of the magnetic field at large heliocentric distances to processes in and above the photosphere. A Fisk-Parker hybrid model that is valid for the whole heliosphere (Burger and Hitge 2004, ApJL, 617) and the whole solar cycle (Kruger 2006, …
Characteristics of cumulative particle fluences at different heliospheric radii
Király, Péter
Normalized cumulative particle fluence plots are very useful for characterizing the variability of interplanetary suprathermal and energetic particle fluxes on various time scales. For some applications it is practicable to describe the deviations of annual fluence plots from straight lines by a single parameter (the Kolmogorov or K parameter), an…
Radial diffusion coefficients of 1-30 MeV protons in the outer heliosphere
Kecskeméty, K.; Logachev, Yu. I.; Zeldovich, M. A.
Radial variations of quiet-time fluxes of ~1-30 MeV protons are examined at distances of 2-85 AU using Voyager 1-2 (LECP, CRS) and Ulysses (LET) data. Attention is focused on the solar cycle minima of 1985-87 and 1995-97. Gradient values calculated from particle fluxes show an increase between 30 and 70 AU during the recovery phases of galactic co…