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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…
Acceleration of the solar wind as a result of the reconnection of open magnetic flux with coronal loops
Fisk, L. A.
There are compelling observations of a clear anticorrelation between solar wind flow speed and coronal electron temperature, as determined from solar wind ionic charge states. A simple theory is presented which can account for these observations, including the functional form of the correlation: Solar wind flow speed squared varies essentially lin…
Using an MHD simulation to interpret the global context of a coronal mass ejection observed by two spacecraft
Lario, D.; Odstrcil, D.; Riley, Pete +4 more
In late February 1999 the ACE spacecraft observed a coronal mass ejection (CME) at 1 AU, in the ecliptic plane. Thirteen days later, Ulysses observed a CME at 5 AU and 22°S. We present a detailed analysis of the plasma, magnetic field, and composition signatures of these two events. On the basis of this comparison alone, it is not clear that the t…
Trapping of Solar Energetic Particles by the Small-Scale Topology of Solar Wind Turbulence
Matthaeus, W. H.; Ruffolo, D.; Chuychai, P.
The transport of energetic particles perpendicular to the mean magnetic field in space plasmas has long been viewed as a diffusive process. However, there is an apparent conflict between recent observations of solar energetic particles (SEPs): (1) Impulsive solar flares can exhibit ``dropouts'' in which the SEP intensity near Earth repeatedly disa…
Discovery of GRB 020405 and Its Late Red Bump
Piro, L.; Mitrofanov, I.; Axelrod, T. S. +41 more
We present the discovery of GRB 020405 made with the Interplanetary Network (IPN). With a duration of 60 s, the burst appears to be a typical long-duration event. We observed the 75 arcmin2 IPN error region with the Mount Stromlo Observatory's 50 inch robotic telescope and discovered a transient source that subsequently decayed and was …
Implications of the observed anticorrelation between solar wind speed and coronal electron temperature
Gloeckler, George; Geiss, Johannes; Zurbuchen, Thomas H.
Electron temperatures at the source of the solar wind are now obtained routinely and continuously from measurements of charge states of solar wind ions with modern solar wind composition spectrometers over a wide range of solar wind speeds. While the general anticorrelation between solar wind speed and electron temperature was previously noted, th…
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…
Ulysses COSPIN observations of cosmic rays and solar energetic particles from the South Pole to the North Pole of the Sun during solar maximum
Balogh, A.; Kunow, H.; Posner, A. +10 more
In 2000-2001 Ulysses passed from the south to the north polar regions of the Sun in the inner heliosphere, providing a snapshot of the latitudinal structure of cosmic ray modulation and solar energetic particle populations during a period near solar maximum. Observations from the COSPIN suite of energetic charged particle telescopes show that lati…
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 …
A tilted-dipole MHD model of the solar corona and solar wind
Goldstein, M. L.; Usmanov, A. V.
We simulate the three-dimensional structure of the heliosphere during solar activity minimum by specifying boundary conditions at the coronal base. We compare the output of the model with Ulysses observations obtained during the spacecraft's first fast latitude transition in 1994-1995. The polytropic MHD equations are solved for a steady coronal o…