Search Publications
Magnetic fields in the Venus ionosphere: Dependence on the IMF direction—Venus express observations
Woch, J.; Wei, Y.; Zhang, T. L. +2 more
The structure of the magnetized ionosphere of Venus is investigated using the magnetometer and plasma (Analyzer of Space Plasmas and Energetic Atoms 4) data from the Venus Express spacecraft. Observations surveying the low-altitude (h ≤ 250 km) ionosphere were made at solar zenith angles ≥ 75°. The magnetic field permeating the Venus ionosphere at…
Density waves in Titan's upper atmosphere
Yelle, R. V.; Cui, J.; Müller-Wodarg, I. C. F. +2 more
Analysis of the Cassini Ion Neutral Mass Spectrometer data reveals the omnipresence of density waves in various constituents of Titan's upper atmosphere, with quasi-periodical structures visible for N2, CH4,29N2, and some of the minor constituents. The N2 amplitude lies in the range of ≈4%-16%…
Developing a self-consistent description of Titan's upper atmosphere without hydrodynamic escape
Bougher, Stephen W.; Hunter Waite, J.; Bell, Jared M. +4 more
In this study, we develop a best fit description of Titan's upper atmosphere between 500 km and 1500 km, using a one-dimensional (1-D) version of the three-dimensional (3-D) Titan Global Ionosphere-Thermosphere Model. For this modeling, we use constraints from several lower atmospheric Cassini-Huygens investigations and validate our simulation res…
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…