Search Publications
Tracking corotating interaction regions from the Sun through to the orbit of Mars using ACE, MEX, VEX, and STEREO
Fränz, M.; Davies, J. A.; Lester, M. +3 more
We study the propagation of corotating interaction regions (CIRs) through the inner heliosphere during the solar minimum of 2007-2008 using the Advanced Composition Explorer (ACE), Mars Express (MEX), Venus Express (VEX), and the Solar Terrestrial Relations Observatory (STEREO). We present observations of 24 CIRs observed during the period from 1 …
Revisiting Time History of Events and Macroscale Interactions during Substorms (THEMIS) substorm events implying magnetic reconnection as the substorm trigger
Lui, A. T. Y.
A recent trend in substorm research is the time history approach, motivated by the NASA mission Time History of Events and Macroscale Interactions during Substorms (THEMIS). We revisit three THEMIS substorm events recently reported to indicate magnetic reconnection as the substorm trigger. The evidence for the occurrence of magnetic reconnection i…
On the simultaneity of substorm onset between two hemispheres
Misawa, H.; Parks, G. K.; Décréau, P. M. E. +13 more
Simultaneous observations of auroral kilometric radiation from the Northern and Southern Hemispheres showed some cases in which the buildup of field-aligned acceleration occurred only in one hemisphere at the substorm onset. This indicates that a substorm does not always complete the current system by connecting the cross-tail current with both no…
Electron energetics in the Enceladus torus
Cravens, T. E.; Robertson, I. P.; Perry, M. +4 more
The inner magnetosphere of Saturn contains both neutral gas and plasma whose composition is dominated by water group ion species. This gas is distributed in a torus-shaped region located near the orbit of Enceladus. The source of this gas is the predominately water vapor plume located in the south polar region of Saturn's icy satellite Enceladus. …
Evidence of surface wave on the dusk flank of Saturn's magnetopause possibly caused by the Kelvin-Helmholtz instability
Dougherty, M. K.; Lucek, E.; Masters, A. +1 more
Boundary waves on Saturn's dusk side magnetopause were identified from magnetopause crossings made by the Cassini spacecraft. These crossings occurred over a 48 h period from 14 July to 15 July 2007 when Cassini was on the inbound leg of revolution (Rev.) 48, and were located at around 17:00 SLT at low latitudes above the equatorial plane. The bou…
In situ evidence for interplanetary magnetic field induced tail twisting associated with relative displacement of conjugate auroral features
Rème, H.; Sato, N.; Ogawa, Y. +4 more
We provide in situ evidence for a twisted near-Earth tail configuration that is responsible for the time sequence of conjugate auroral features associated with relative interhemispheric displacement during a weak substorm, as reported by Motoba et al. (2010). We analyzed the magnetic field data observed using four Cluster satellites in the vicinit…
What causes the flux excess in the heliospheric magnetic field?
Smith, Edward J.
Ulysses results indicate that the total magnetic flux inside the heliosphere, Φ, can be obtained from the radial field component measured at a single spacecraft multiplied by the square of the radial distance and averaged over a solar rotation, < r2BR >. However, that result is contrary to a large increase in Φ with dis…
Velocity distributions of superthermal electrons fitted with a power law function in the magnetosheath: Cluster observations
Zhang, Tielong; Wang, Shui; Lu, Quanming +3 more
Satellite observations have revealed that superthermal electrons in space plasma generally possess a power law distribution. In this paper, we utilize a power law function to model the omnidirectional differential fluxes of superthermal electrons observed by Cluster in the magnetosheath. By assuming an isotropic pitch angle distribution and perfor…
Unusual nonlinear waves in the Venusian magnetosheath
Zhang, T. L.; Walker, S. N.; Balikhin, M. A. +4 more
Within the Venusian magnetosheath, Venus Express has observed the existence of high-amplitude, nonlinear waves which have been interpreted as large-scale nonlinear rotational structures within the magnetic field. A number of mechanisms have been proposed that can be used to explain their origin. Venus Express data have been searched for other exam…
Modified solar flux index for upper atmospheric applications
Maruyama, Takashi
The F10.7 solar flux index was modified in order to better describe short-term variations in solar extreme ultraviolet (EUV) irradiance for application in ionosphere and thermosphere studies. Several parameters were computed from the F10.7 time series with the assistance of an artificial neural network (ANN) technique, and th…