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Ulysses observations of the magnetic field structure within CIRs
Forsyth, R. J.; Dunlop, M. W.; Clack, D.
Ulysses encountered two separate sequences of corotating interaction regions (CIRs) in 1992-3 and 1996-7 when the spacecraft was in the southern and northern solar hemispheres, respectively. We have examined magnetometer data from one event observed in each hemisphere. Using two separate analytical methods we provide evidence for the magnetic fiel…
Long-term behavior of Jovian bKOM and nKOM radio emissions observed during the Ulysses-Jupiter encounter
Kaiser, M. L.; Desch, M. D.; Reiner, M. J.
We present observational evidence that the long-term behavior of Jovian bKOM and nKOM radio emissions observed during the Ulysses-Jupiter encounter was controlled by the sector structure of the solar wind. Specifically, we found brightenings in the Jovian bKOM emission, followed by a sudden cessation of the bKOM emission and an onset of an nKOM “e…
Influence of electrophilic species on the lower ionosphere of Titan
Rodrigo, R.; López-Moreno, J. J.; Molina-Cuberos, G. J.
The galactic cosmic rays induced ionosphere of Titan is studied from 0 to 70 km. We resent here a new model developed for calculating the concentration of cations, anions, and electrons depending on the mixing ratio of electrophilic species present in the atmosphere of Titan. The existence of neutral species in which electrons can be attached by t…
Fluctuations of the heliospheric magnetic field and the anisotropy of pickup ions
Balogh, A.; Erdős, G.; Németh, Z.
Pitch angle distribution of interstellar pickup ions at high heliographic latitude is studied. Based on high time resolution magnetic field observations by Ulysses during the south polar pass in 1994, we have determined the angular distribution of particles at the moment of ionization. Due to large deviations of the field from Parker's spiral, it …
Coronal mass ejections detected in solar mean magnetic field
Boberg, Fredrik; Lundstedt, Henrik
One minute resolution solar mean magnetic field sequences during 74 coronal mass ejection events are analyzed using wavelet transforms. A significant fraction of the resulting wavelet power spectra shows a characteristic peak at the time of the coronal mass ejection. With an average period of 13 minutes, the signature in the solar mean field is mo…
Recurrence in MeV proton fluxes and anisotropies at 5 AU from the Sun
Balogh, A.; Dalla, S.
We report the observation of a recurrent pattern in proton fluxes and anisotropies at 5.2 AU from the Sun, made by the Anisotropy Telescopes on board the Ulysses spacecraft between April 1998 and May 1999, during the rising phase of solar cycle 23. The time delay between recurrent features of the pattern is not constant and increases from 122 to 1…
Heliospheric magnetic field polarity inversions at high heliographic latitudes
Balogh, A.; Horbury, T. S.; Lucek, E. A. +2 more
The heliospheric magnetic field over the poles of the sun has been examined to identify intervals when the polarity of the magnetic field deviates significantly from the calculated Parker spiral, using Ulysses observations in 1994 and 1995, near solar minimum. Intervals with deviation > 90° have been identified, corresponding to magnetic field …
Long-term drift of the coronal source magnetic flux and the total solar irradiance
Lockwood, M.; Stamper, R.
We test the method of Lockwood et al [1999] for deriving the coronal source flux from the geomagnetic aa index and show it to be accurate to within 12% for annual means and 4.5% for averages over a sunspot cycle. Using data from four solar constant monitors during 1981-1995, we find a linear relationship between this magnetic flux and the total so…
Coronagraph observations of inflows during high solar activity
Simnett, G. M.; Howard, R. A.; Sheeley, N. R., Jr. +2 more
Since the start of the SOHO mission three years ago, the Large Angle Spectrometric Coronagraph (LASCO) has recorded numerous examples of small, faint features moving inward through the corona. The inflows are observed at heliocentric distances of 2-4 Rs and became increasingly common during 1998, as solar and coronal mass ejection (CME)…
Astrometric and space-geodetic observations of polar wander
Vondrák, Jan; Gross, Richard S.
Optical astrometric measurements of star positions taken during the past century have been recently re-reduced using the final Hipparcos star catalog in order to determine variations in the mean location of the Earth's rotation pole with respect to the Earth's crust. This newly available polar motion series, which is the longest homogeneous polar …