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Ulysses observations of a discrete wavepacket upstream of an interplanetary shock
Balogh, A.; Lucek, E. A.
We present a single example of a previously unidentified type of upstream wave structure, found several minutes ahead of a forward propagating, oblique interplanetary shock observed on day 6, 1992, using Ulysses magnetometer data. The wave appears as an isolated high frequency wavepacket associated with a larger scale compressive structure. In the…
A new look at the nature of comet Halley's LF electromagnetic waves: Giotto observations
Neubauer, Fritz M.; Tsurutani, Bruce T.; Glassmeier, Karl-Heinz +1 more
All of the comet Halley high-time resolution magnetic field data have been examined to determine the nature of the “turbulence” and its difference from that of comets Giacobini-Zinner and Grigg-Skjellerup. Although much of the wave appears unpolarized, occasionally there are intervals of clear order. We find several interesting new wave polarizati…
The Ulysses north polar pass: Latitudinal gradients of anomalous cosmic ray O, N And Ne
Sanderson, T. R.; Marsden, R. G.; Trattner, K. J.
A key finding of the Ulysses mission has been the absence of large latitudinal gradients in the Anomalous Cosmic Ray (ACR) component. Studies using data from several satellites have consistently shown a small (∼ 2%/deg.) positive latitudinal gradient for anomalous O, N and Ne in the energy range 4 to 30 MeV/n, and even smaller gradients for ACR He…
Ulysses observations of short-period (≤30 Days) modulation of the galactic cosmic rays
Keppler, E.; Kunow, H.; Heber, B. +3 more
A frequency analysis of the short-period modulation of the GCR as seen by instruments aboard Ulysses shows interesting temporal variations. In particular, during an approximate five-month period from December 1993 to May 1994, the modulation was not the usual 26 days but more than 29 days. The CIR-associated MeV ions did not exhibit this period sh…
The Latitudinal Structure of the Solar Wind in the Vicinity of the Solar Equator near Solar Minimum: 1986 and Predictions for 1997
Gazis, P. R.
In situ observations by different spacecraft have shown that the heliospheric current sheet (HCS) is associated with a narrow band of low speed high density solar wind. The inclination of the HCS and the three-dimensional structure of solar wind streams is related to the inclination of the coronal neutral line. Observations from the Ulysses spacec…
Latitudinal structure of the heliospheric current sheet and corotating streams measured by WIND and ULYSSES
Tsurutani, B. T.; Steinberg, J. T.; Goldstein, B. E. +5 more
All heliospheric current sheet (HCS) crossings and corotating solar wind streams detected by both WIND and Ulysses have been identified. These measurements were made when Ulysses was in its fast latitudinal scan (at a heliocentric radial distance of ∼1.4 AU) and WIND was in the ecliptic plane near the Earth. Instantaneous solar wind velocities are…
Coronal radio sounding: Non-Gaussian turbulence in the source regions of slow and fast solar wind
Pätzold, M.; Bird, M. K.; Karl, J.
Structure functions of arbitrary order are analyzed using differential phase scintillation data obtained during the fourth solar conjunction of the Ulysses spacecraft in February-March 1995. The scaling features of these structure functions clearly discriminate between electron density fluctuations observed in coronal holes versus coronal streamer…
Pick-up ions and associated wave energy transport at comet P/Halley: A case study
Neubauer, Fritz M.; Glassmeier, Karl-Heinz; Söding, Anne +1 more
During the flyby of the spacecraft Giotto at comet p/Halley Poynting vectors and Elsässer variables have been determined to study wave propagation directions. The observed wave properties are compared with the theoretically predicted RH-, LH+ and LH- wave modes. Between 10:36 and 19:11 SCET on March 13, 1986 the pr…
The Lyman-α line from the solar wind acceleration region: Results from an eight-moment approximation two-fluid solar wind model
Olsen, Espen Lyngdal
We investigate neutral hydrogen in an eight-moment, two-fluid, high speed solar wind model. In this model the proton heat flux decreases rapidly in the solar wind acceleration region, and extended coronal heating of the proton gas leads to high coronal proton temperatures and large solar wind flow speeds. The properties of the Lyman-α line from th…