Search Publications
The solar type II radio bursts of 7 March 2012: Detailed simulation analyses
Cairns, Iver H.; Schmidt, J. M.; Lobzin, V. V.
Type II solar radio bursts are often indicators for impending space weather events at Earth. They are consequences of shock waves driven by coronal mass ejections (CMEs) that move outward from the Sun. We simulate such type II radio bursts by combining elaborate three-dimensional (3-D) magnetohydrodynamic (MHD) predictions of realistic CMEs near t…
Type II solar radio bursts predicted by 3-D MHD CME and kinetic radio emission simulations
Cairns, Iver H.; Schmidt, J. M.
Impending space weather events at Earth are often signaled by type II solar radio bursts. These bursts are generated upstream of shock waves driven by coronal mass ejections (CMEs) that move away from the Sun. We combine elaborate three-dimensional (3-D) magnetohydrodynamic predictions of realistic CMEs near the Sun with a recent analytic kinetic …
Survey analysis of chorus intensity at Saturn
Gurnett, D. A.; Hospodarsky, G. B.; Woodfield, E. E. +5 more
In order to conduct theoretical studies or modeling of pitch angle scattering of electrons by whistler mode chorus emission at Saturn, a knowledge of chorus occurrence and magnetic intensity levels, PB, as well as the distribution of PB relative to frequency and spatial parameters is essential. In this paper an extensive surv…
Ion composition in interchange injection events in Saturn's magnetosphere
Thomsen, M. F.; Wilson, R. J.; Tokar, R. L. +10 more
Interchange injection events are commonly observed by the Cassini spacecraft in the region between about 6 and 12 Rs (1 Rs = 60,268 km) and even frequently beyond. In this study, 13 examples of interchange injection events are identified in Cassini/Cassini Plasma Spectrometer data under special conditions such that time-of-fl…
Influence of dust loading on atmospheric ionizing radiation on Mars
Gronoff, Guillaume; Mertens, Christopher J.; Norman, Ryan B.
Measuring the radiation environment at the surface of Mars is the primary goal of the Radiation Assessment Detector on the NASA Mars Science Laboratory's Curiosity rover. One of the conditions that Curiosity will likely encounter is a dust storm. The objective of this paper is to compute the cosmic ray ionization in different conditions, including…
Mars Express observations of high altitude planetary ion beams and their relation to the "energetic plume" loss channel
Liemohn, Michael W.; Johnson, Blake C.; Fränz, Markus +1 more
This study presents observational evidence of high-energy (ions >2 keV) beams of planetary ions above Mars' induced magnetospheric boundary (IMB) and relates them with the energetic plume loss channel calculated from numerical models. A systematic search of the Mars Express (MEX) ion data using an orbit filtering criteria is described, using ma…
Data-based modeling of the geomagnetosphere with an IMF-dependent magnetopause
Tsyganenko, N. A.
The paper presents first results of the data-based modeling of the geomagnetospheric magnetic field, using the data of Polar, Geotail, Cluster, and Time History of Events and Macroscale Interactions during Substorms satellites, taken during the period 1995-2012 and covering 123 storm events with SYM-H ≥ -200 nT. The most important innovations in t…
Control of periodic variations in Saturn's magnetosphere by compressional waves
Kivelson, Margaret Galland; Jia, Xianzhe
Many of the periodic variations observed in Saturn's magnetosphere can be linked directly to the presence of a rotating pattern of field-aligned currents that link the northern and southern ionospheres with each other and with the magnetosphere. Such a current system is incorporated in a magnetohydrodynamic simulation that has previously been show…
Polar confinement of Saturn's magnetosphere revealed by in situ Cassini observations
Coates, A. J.; Dougherty, M. K.; Masters, A. +4 more
Plasma rotation plays a large role in determining the size and shape of Saturn's disk-like magnetosphere. A magnetosphere more confined to the equator in the polar regions is expected as a result of the interaction between this type of obstacle and the solar wind. In addition, at times away from equinox, a north-south asymmetry is expected where t…
Keogram analysis of ENA images at Saturn
Mitchell, D. G.; Carbary, J. F.
Keograms are constructed from azimuthal profiles of energetic hydrogen atoms (25-55 keV) from Saturn's magnetosphere. The keograms exhibit linear structures or "tracks" that reveal prograde rotational motion of features or "blobs" in the energetic neutral atom (ENA) images. From polynomial fits, the first derivatives of these tracks are used to es…