Search Publications
Global Distribution of the Solar Wind Flux and Velocity From SOHO/SWAN During SC-23 and SC-24
Schmidt, W.; Quémerais, E.; Koutroumpa, D. +1 more
We analyze SOHO (SOlar Heliospheric Observatory)/SWAN (Solar Wind ANisotropy) hydrogen Lyman-α data collected between 1996 and 2018 to derive the solar wind latitudinal distribution over time. Full-sky interplanetary Lyman-α maps are inverted to derive the total hydrogen ionization rate latitude profiles, normalized to proton charge-exchange and p…
The interplanetary magnetic field observed by Juno enroute to Jupiter
Connerney, John E. P.; Gruesbeck, Jacob R.; Gershman, Daniel J. +1 more
The Juno spacecraft was launched on 5 August 2011 and spent nearly 5 years traveling through the inner heliosphere on its way to Jupiter. The Magnetic Field Investigation was powered on shortly after launch and obtained vector measurements of the interplanetary magnetic field (IMF) at sample rates from 1 to 64 samples/second. The evolution of the …
Interstellar He+ ring-beam distributions: Observations and implications
Galvin, Antoinette B.; Wimmer-Schweingruber, Robert F.; Berger, Lars +1 more
We report systematic measurements of the distribution of the incident angle of interstellar pickup He+ ions as observed by STEREO/Plasma and Supra-Thermal Ion Composition (PLASTIC). We have organized these observations according to the angle spanned by the Interplanetary Magnetic Field (IMF), B→, and the bulk solar wind velocity, vsw
The reversal of the rotational modulation rates of the north and south components of Saturn kilometric radiation near equinox
Gurnett, D. A.; Persoon, A. M.; Kurth, W. S. +5 more
It has been known for many years that Saturn emits intense radio emissions at kilometer wavelengths and that this radiation is modulated by the rotation of the planet at a rate that varies slowly on time scales of years. Recently it has been shown that the radio emission consists of two components that have different rotational modulation rates, o…
Oxygen flux in the solar wind: Ulysses observations
Zurbuchen, Thomas H.; von Steiger, Rudolf; McComas, David J.
We use the complete set of Ulysses solar wind data to conduct a comprehensive determination of the oxygen flux in relation to the proton flux in the solar wind during a wide range of solar activity levels. The data cover the heliosphere between 1.3 and 5.4 AU and, due to the unique orbit of Ulysses, all of the heliographic latitudes within ±80°. W…
First results from the Venetia Burney Student Dust Counter on the New Horizons mission
James, David; Horányi, Mihály; Poppe, Andrew +1 more
The Venetia Burney Student Dust Counter (SDC) onboard the New Horizons mission is an impact-based dust detector designed to map the size and spatial variability of the interplanetary dust population throughout the solar system. SDC consists of fourteen permanently polarized polyvinylidene fluoride detectors that register a charge upon impact by hy…
Differences in solar wind cross-helicity and residual energy during the last two solar minima
Perri, S.; Balogh, A.
The minimum of solar cycle 23 exhibited anomalous characteristics with respect to its predecessors. Other than the differences in the standard indicators of activity, such as sunspots, polar magnetic fields were also found to be different. These differences had a range of effects in the solar wind. In this work we study the Alfvénicity and the res…
Rotation period of Jupiter from the observation of its magnetic field
Russell, C. T.; Yu, Z. J.
To determine the Jovian internal rotation rate, historically one has used the repetition period (periodicity) of decametric and decimetric radio waves. The period with which decametric and decimetric radio waves recur on Jupiter (the System III period) was defined by the IAU in 1965 to be 9h 55m 29.71s, based on early radio astronomical data. A mo…
Radial and latitudinal gradients of anomalous cosmic ray oxygen in the inner heliosphere
Mewaldt, R. A.; Cummings, A. C.; Marsden, R. G. +2 more
We use data from the Ulysses, Advanced Composition Explorer, and Solar Terrestrial Relations Observatory spacecraft to determine the radial and latitudinal gradients of anomalous cosmic ray oxygen in two energy ranges from 4.5-15.6 MeV/nuc in the inner heliosphere for the first time during an A<0 part of the solar cycle. Using measurements from…
Weaker solar wind from the polar coronal holes and the whole Sun
McComas, D. J.; Goldstein, B. E.; Schwadron, N. A. +4 more
Observations of solar wind from both large polar coronal holes (PCHs) during Ulysses' third orbit showed that the fast solar wind was slightly slower, significantly less dense, cooler, and had less mass and momentum flux than during the previous solar minimum (first) orbit. In addition, while much more variable, measurements in the slower, in-ecli…