Search Publications
Radial evolution of the electron distribution functions in the fast solar wind between 0.3 and 1.5 AU
McComas, D. J.; Maksimovic, M.; Issautier, K. +8 more
Observed electron distribution functions of the solar wind permanently exhibit three different components: a thermal core and a suprathermal halo, which are always present at all pitch angles, and a sharply magnetic field aligned "strahl" which is usually anti-sunward moving. Whereas Coulomb collisions can explain the relative isotropy of the core…
Simultaneous Chandra X ray, Hubble Space Telescope ultraviolet, and Ulysses radio observations of Jupiter's aurora
MacDowall, R. J.; Waite, J. H.; Cravens, T. E. +8 more
Observations of Jupiter carried out by the Chandra Advanced CCD Imaging Spectrometer (ACIS-S) instrument over 24-26 February 2003 show that the auroral X-ray spectrum consists of line emission consistent with high-charge states of precipitating ions, and not a continuum as might be expected from bremsstrahlung. The part of the spectrum due to oxyg…
Magnetic field variations in the Jovian magnetotail induced by solar wind dynamic pressure enhancements
Yokoyama, Takaaki; Tao, Chihiro; Kataoka, Ryuho +2 more
In order to understand the response of the Jovian magnetosphere to solar wind dynamic pressure enhancements, we investigate magnetic field variations observed by the Galileo spacecraft. The lack of solar wind monitoring just upstream of the Jovian magnetosphere is overcome by simulating a one-dimensional magnetohydrodynamic (MHD) propagation of th…
On the sources of fast and slow solar wind
Schwadron, N. A.; Landi, E.; Feldman, U.
The slow speed solar wind as measured at the Earth orbit and beyond is characterized by its velocity of ≃400 km s-1, by its coronal composition and by its frozen-in temperature (from carbon charge-states) of 1.4-1.6 × 106 K. In contrast the fast speed solar wind is characterized by its velocity of ≃750 km s-1, its …
Global structure of Jupiter's magnetospheric current sheet
Khurana, Krishan K.; Schwarzl, Hannes K.
Jupiter's magnetosphere contains a gigantic sheet-like structure located near its dipole magnetic equator that contains most of the plasma and energetic particles swirling in Jupiter's magnetosphere. Called the "current sheet," it behaves like a rigid structure inside a radial distance of ∼50 RJ where the periodic reversals of the B
Characteristics of the interplanetary coronal mass ejections in the heliosphere between 0.3 and 5.4 AU
Wang, C.; Richardson, J. D.; Du, D.
We identify and characterize interplanetary coronal mass ejections (ICMEs) observed by spacecraft in the solar wind, namely Helios 1 and 2, PVO, ACE, and Ulysses, which together cover heliocentric distances from 0.3 to 5.4 AU. The primary identification signature used to look for ICMEs is abnormally low proton temperatures. About 600 probable ICME…
Heliospheric energetic particle observations during the October-November 2003 events
Livi, S.; Russell, C. T.; Lario, D. +4 more
The intense level of solar activity recorded from 19 October to 12 November 2003 led to unusually high energetic particle intensities observed throughout the heliosphere. The fleet of spacecraft distributed in the inner and outer heliosphere offers us the opportunity to study both the effects of these events in different regions of the heliosphere…
Prediction and understanding of the north-south displacement of the heliospheric current sheet
Hoeksema, J. T.; Scherrer, P. H.; Zhao, X. P.
On the basis of Wilcox Solar Observatory observations of the photospheric magnetic field and the potential field-source surface model, we compare the solid angles occupied by the positive source surface field with that of the negative. We develop an algorithm to quantitatively estimate and understand the positive-negative displacement of the helio…
Solar wind from the coronal hole boundaries
Geiss, J.; McComas, D. J.; Schwadron, N. A. +3 more
Recent studies using in situ observations established that the interface between fast and slow wind in interplanetary space has two distinct parts: a smoothly varying boundary layer flow that flanks fast wind from coronal holes and a sharper plasma discontinuity between intermediate and slow solar wind. Other studies using in situ observations and…
From the Sun to the outer heliosphere: Modeling and analyses of the interplanetary propagation of the October/November (Halloween) 2003 solar events
Sun, Wei; Intriligator, Devrie S.; Dryer, Murray +3 more
We use the space weather validated 3-D HAFv2 model to help us study the interplanetary propagation of the October/November 2003 solar eruptions from the Sun to >90 AU and over a wide range of heliolongitudes and heliolatitudes. The HAFv2 model predictions at ACE (1 AU), Ulysses (5.23 AU), Cassini (8.67 AU), Voyager 2 (73 AU), and Voyager 1 (93 …