Search Publications
Comparative time-series analysis of MeV electron data by Ulysses and Pioneer 10/11 in the Jovian magnetosphere
Potgieter, M. S.; Heber, B.; Kopp, A. +1 more
The dynamics of the Jovian magnetosphere is dominated by the planet's fast rotation with a period of ~ 10 h. Within the magnetosphere, this periodicity can in particular be seen in the temporal variation of the spectral index of MeV electrons: every ~ 10 h the counting rates show a maximum (minimum), while the spectral index shows a minimum (maxim…
Current sheets from Ulysses observation
Li, G.; Miao, B.; Peng, B.
Current sheet is a significant source of solar wind MHD turbulence intermittency. It has long been recognized that these structures can arise from non-linear interactions of MHD turbulence. Alternatively, they may also be relic structures in the solar wind that have a solar origin, e.g., magnetic walls of flux tubes that separate solar wind plasma…
On arc-polarized structures in the solar wind
Haaland, S. E.; Paschmann, G.; Sonnerup, B. U. Ö.
A theoretical model is proposed to account for some of the behavior of arc-polarized magnetic structures seen in the solar wind. To this end, an exact analytical solution is developed that describes infinite plane wave trains of arbitrary amplitude in a plasma governed by ideal Hall MHD. The main focus is on intermediate-mode wave trains, which di…
Velocity fluctuations in polar solar wind: a comparison between different solar cycles
Bavassano, B.; Bruno, R.; D'Amicis, R.
The polar solar wind is a fast, tenuous and steady flow that, with the exception of a relatively short phase around the Sun's activity maximum, fills the high-latitude heliosphere. The polar wind properties have been extensively investigated by Ulysses, the first spacecraft able to perform in-situ measurements in the high-latitude heliosphere. The…
Magnetic clouds seen at different locations in the heliosphere
Zhukov, A. N.; Rodriguez, L.; Mandrini, C. H. +9 more
We analyze two magnetic clouds (MCs) observed in different points of the heliosphere. The main aim of the present study is to provide a link between the different aspects of this phenomenon, starting with information on the origins of the MCs at the Sun and following by the analysis of in-situ observations at 1 AU and at Ulysses. The candidate sou…
Observations of recurrent cosmic ray decreases during solar cycles 22 and 23
Gómez-Herrero, R.; Heber, B.; Müller-Mellin, R. +5 more
During solar cycle 22, the modulation of several hundred MeV galactic cosmic rays (GCRs) by recurrent and transient cosmic ray decreases was observed by the Ulysses spacecraft on its descent towards the solar south pole. In solar cycle 23, Ulysses repeated this trajectory segment during a similar phase of the solar cycle, but with opposite heliosp…
Energetic particle measurements from the Ulysses/COSPIN/LET instrument obtained during the August/September 2005 events
Forsyth, R. J.; Marsden, R. G.; Tranquille, C. +3 more
We report recent observations of energetic particles at energies 1-40 MeV/n made by the COSPIN/LET instrument onboard the Ulysses spacecraft during the period of intense solar activity in August/September 2005 during the declining phase of solar cycle 23. Ulysses, having started its climb to high southern latitudes for the third time, was located …
Testing the local spacetime dynamics by heliospheric radiocommunication methods
Siewert, M.; Fahr, H. -J.
According to general relativistic theories, cosmological spacetime is dynamic. This prediction is in excellent agreement with the huge majority of astronomical observations on large cosmic scales, especially the observations of cosmological redshifts of distant galaxies. However, on scales of heliospheric distances, verifications of general relati…
Magnetopause reconnection rate estimates for Jupiter's magnetosphere based on interplanetary measurements at ~5AU
McComas, D. J.; Nichols, J. D.; Cowley, S. W. H.
We make the first quantitative estimates of the magnetopause reconnection rate at Jupiter using extended in situ data sets, building on simple order of magnitude estimates made some thirty years ago by Brice and Ionannidis (1970) and Kennel and Coroniti (1975, 1977). The jovian low-latitude magnetopause (open flux production) reconnection voltage …
Alfvénic turbulence in solar wind originating near coronal hole boundaries: heavy-ion effects?
Bavassano, B.; Pietropaolo, E.; Bruno, R. +1 more
The mid-latitude phases of the Ulysses mission offer an excellent opportunity to investigate the solar wind originating near the coronal hole boundaries. Here we report on Alfvénic turbulence features, revealing a relevant presence of in-situ generated fluctuations, observed during the wind rarefaction phase that charaterizes the transition from f…