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The three-dimensional solar wind around solar maximum
McComas, D. J.; Goldstein, B. E.; Schwadron, N. A. +3 more
Ulysses is now completing its second solar polar orbit, dropping back down in latitude as the Sun passes through its post-maximum phase of the solar cycle. A mid-sized circumpolar coronal hole that formed around solar maximum in the northern hemisphere has persisted and produced a highly inclined CIR, which was observed from ~70°N down to ~30°N. W…
Properties of high heliolatitude solar energetic particle events and constraints on models of acceleration and propagation
Balogh, A.; Krucker, S.; Dalla, S. +10 more
We analyse 9 large solar energetic particle (SEP) events detected by the Ulysses spacecraft at high heliolatitudes during the recent solar maximum polar passes. Properties of time intensity profiles from the Ulysses/COSPIN instrument are compared with those measured by SOHO/COSTEP and Wind/3DP near Earth. We find that onset times and times to maxi…
Bashful ballerina: Southward shifted heliospheric current sheet
Mursula, K.; Hiltula, T.
It is known since long [Rosenberg and Coleman, 1969] that one of the two sectors of the interplanetary magnetic field (IMF) observed at the Earth's orbit dominates at high heliographic latitudes during solar minimum times, reflecting the poloidal structure of the global solar magnetic field at these times. Here we find that while this latitudinal …
Properties of high-latitude CME-driven disturbances during Ulysses second northern polar passage
St. Cyr, O. C.; Reisenfeld, D. B.; Forsyth, R. J. +2 more
Ulysses observed five coronal mass ejections (CMEs) and their associated disturbances while the spacecraft was immersed in the polar coronal hole (CH) flow above 70° N in late 2001. Of these CMEs, two were very fast (>850 km s-1) driving strong shocks in the wind ahead, and two others were over-expanding. The two fast CMEs were obser…
When will Voyager 1 and 2 cross the termination shock?
Gloeckler, George; Izmodenov, Vlad; Malama, Yuri
Our Solar System moves through a warm (~6,500 K), partly ionized local interstellar cloud (LIC) with a relative speed of ~26 km/s. The solar wind interacts with the LIC to form a cavity around the Sun called the heliosphere. The solar wind meets the interstellar charged component at the heliopause, where solar wind pressure balances the pressure o…
Solar magnetic field reversal as seen at Ulysses
Balogh, André; Smith, Edward J.; Jones, Geraint H.
The rapid motion of the Ulysses spacecraft from high southern to high northern latitudes in 2000-2001 provided an excellent opportunity to make inferences regarding the solar magnetic dipole's behaviour around solar maximum. A simple dipole model is fitted to Ulysses measurements of the polarity of the heliospheric magnetic field mapped back to th…
Propagation of energetic particles in the high-latitude high-speed solar wind
Dalla, S.; Forsyth, R. J.; Gosling, J. T. +4 more
We present observations of energetic particles in the energy range ~1 MeV to ~100 MeV made by the COSPIN instrument on board the Ulysses spacecraft during the recent second northern polar pass. For a short time during this pass the Ulysses spacecraft was at high heliographic latitude, above the current sheet, and immersed in high-speed solar-wind …
Heliospheric ``FALTS'': Favored Acceleration Locations at the Termination Shock
McComas, D. J.; Schwadron, N. A.
The standard explanation for Anomalous Cosmic Rays requires strong energization at the heliospheric termination shock. However, the tightly wrapped magnetic spiral in the outer heliosphere produces a quasi-perpendicular shock where it is difficult to accelerate low energy particles. We show that motion of footpoints between regions of fast and slo…
Evolution of the galactic cosmic ray electron to proton ratio: Ulysses COSPIN/KET observations
Kunow, H.; Ferreira, S. E. S.; Potgieter, M. S. +3 more
The Ulysses orbit provides a unique opportunity to study the propagation of cosmic rays in a wide range of heliographic latitudes and during different solar activity and polarity in the inner heliosphere. Around July 2000 the solar magnetic field reversed its global polarity. In late 2000, the electron to proton ratio at the rigidities of 1.2 GV a…
Magnetic clouds with east/west orientated axes observed by Ulysses during solar cycle 23
Forsyth, R. J.; Rees, A.
The second Ulysses orbit of the Sun has provided a unique opportunity for the study of the interplanetary manifestation of coronal mass ejections (ICMEs) over a wide range of heliographic latitudes. The Ulysses dataset between July 1995 and mid April 2003 has been surveyed for magnetic clouds (MCs), a subset of ICMEs. As a result of the rising sol…