Search Publications
Evaluation of solar Type II radio burst estimates of initial solar wind shock speed using a kinematic model of the solar wind on the April 2001 solar event swarm
Dryer, M.; Smith, Z.; Fry, C. D. +5 more
We compare simulation results of real time shock arrival time prediction with observations by the ACE satellite for a series of solar flares/coronal mass ejections which took place between 28 March and 18 April, 2001 on the basis of the Hakamada-Akasofu-Fry, version 2 (HAFv.2) model. It is found, via an ex post facto calculation, that the initial …
Fast acceleration of a CME-related X-ray structure in the low solar corona
Nitta, Nariaki V.; Alexander, David; Metcalf, Thomas R.
We report on a unique observation of the early and rapid acceleration of a fast CME in the low solar corona. The coronal disturbance associated with a LASCO CME and concurrent X1.2 flare on 1998 April 23 was well-observed by the Yohkoh Soft X-ray Telescope. The X-ray observations clearly show an accelerating structure, reaching 800-1100 km/s in ~5…
14-day forecast of solar indices using interplanetary Lyman α background data
Bertaux, Jean-Loup; Quémerais, Eric
We present a new method which can be used to forecast the variations of solar indices on the time scale of a half solar rotation. This method uses the Lyα interplanetary glow data obtained by the SWAN instrument on SOHO. We show how the maps of solar Lyα flux distributions derived from the SWAN data can be linked to the variation of activity on th…
Overview of mirror mode fluctuations in the jovian dusk magnetosheath: Cassini magnetometer observations
André, N.; Erdös, G.; Dougherty, M.
The recent Cassini flyby of Jupiter provides a new unique data set in order to allow tracking of the instability along flow lines down to the distant magnetosheath, as yet unexplored by previous missions. Signatures consistent with mirror mode activity were frequently observed during the flyby in the magnetometer data, appearing at many different …
Three-dimensional energetic ion sounding of the magnetopause using Cluster/RAPID
Zong, Q. -G.; Fritz, T. A.; Wilken, B. +2 more
We present new results using energetic particles to remotely sound the high-latitude magnetopause in three-dimensions. Less than two gyro radii from an absorbing boundary a trapped particle distribution appears non-gyrotropic, as particles start to cross the boundary. Knowing the magnetic field and the particle mass and energy, it is possible to d…
A comparison of mean density and microscale density fluctuations in a CME at 10 Rsolar
Lynch, B. J.; Sheeley, N. R.; Coles, W. A.
We have observed intensity scintillation (IPS) of the radio source 0854 + 201 at 8 GHz on August 2, 2000 during the passage of a coronal mass ejection (CME) across the line of sight. The source was at a distance of 10 Rsolar over the north solar pole. Simultaneous observations with the LASCO C3 instrument allow us to model the mean dens…
Cosmic electron gradients in the inner heliosphere
Heber, Bernd; Clem, John; Evenson, Paul
We report the first determination of the radial gradient of cosmic ray electrons in the inner heliosphere at rigidities of 1.2 and 2.5 GV from 1 to 5 AU. Since this determination was made during the A+ solar polarity state, it also constitutes the only determination for particles in a polarity state opposite to their charge sign. We fin…
Composition measurements above the Southern Solar Polar Region around the solar activity maximum by the Ulysses COSPIN/LET instrument
Sanderson, T. R.; Marsden, R. G.; Tranquille, C. +1 more
In November 2000, during the second southern polar passage (SPP), the Ulysses spacecraft reached its highest heliographic latitude (80.2°) at a solar radial distance of ~2.27 AU. The first SPP in 1994 took place as the level of solar activity was approaching the minimum between the cycles 22 and 23. The recent high-latitude observations during the…
The O+ and O++ emission lines near 834 Å in the quiet sun solar spectrum
Doschek, G. A.
I present quiet Sun solar disk averaged emission line intensities (at the Earth) and the full widths at half maximum intensity (FWHM) for the O+ and O++ emission lines that fall near 834 Å. These lines are important as excitation sources for O+ and O++ emission in the Earth's upper ionosphere, plasmasphe…