Search Publications
A case study of proton precipitation at Mars: Mars Express observations and hybrid simulations
Kallio, E.; Fedorov, A.; Barabash, S. +8 more
Using the data from the Analyzer of Space Plasma and Energetic Atoms (ASPERA-3) experiment on board Mars Express and hybrid simulations, we have investigated the entry of protons into the Martian induced magnetosphere. We discuss one orbit on the dayside with observations of significant proton fluxes at altitudes down to 260 km on 27 February 2004…
Seasonal and clock angle control of the location of flux transfer event signatures at the magnetopause
Milan, S. E.; Fear, R. C.; Palmroth, M.
Most models of flux transfer event (FTE) formation produce pairs of structures which in general move away from the subsolar region and give rise to signatures which can be observed in both the Northern and Southern Hemispheres. The multiple reconnection line (X line) model is unusual as a reconnection-based model that is capable of producing a sin…
Formation, shape, and evolution of magnetic structures in CIRs at 1 AU
McComas, D. J.; Desai, M. I.; Broiles, T. W.
We have surveyed the properties of 153 co-rotating interaction regions (CIRs) observed at 1 AU from January, 1995 through December, 2008. We identified that 74 of the 153 CIRs contain planar magnetic structures (PMSs). For planar and non-planar CIRs, we compared distributions of the bulk plasma and magnetic field parameters. Our identification of …
Kelvin-Helmholtz instabilities at the magnetic cavity boundary of comet 67P/Churyumov-Gerasimenko
Combi, M. R.; Gombosi, T. I.; Rubin, M. +3 more
We investigate the plasma environment of comet 67P/Churyumov-Gerasimenko, the target of the European Space Agency's Rosetta mission. Rosetta will rendezvous with the comet in 2014 at almost 3.5 AU and follow it all the way to and past perihelion at 1.3 AU. During its journey towards the inner solar system the comet's environment will significantly…
An analysis of thermospheric density response to solar flares during 2001-2006
Le, Huijun; Liu, Libo; Wan, Weixing
Previous studies show there are significant thermospheric responses to the two great solar flares on October 28, 2003 (X17.2) and November 4, 2003 (X28). In the present study, we further explored the thermospheric response to all X-class solar flares during 2001-2006. The observed results show that X5 and stronger solar flares can induce an averag…
Radio-loud CMEs from the disk center lacking shocks at 1 AU
MacDowall, R. J.; Kaiser, M. L.; Gopalswamy, N. +4 more
A coronal mass ejection (CME) associated with a type II burst and originating close to the center of the solar disk typically results in a shock at Earth in 2-3 days and hence can be used to predict shock arrival at Earth. However, a significant fraction (about 28%) of such CMEs producing type II bursts were not associated with shocks at Earth. We…
Short large-amplitude magnetic structures (SLAMS) at Venus
Coates, A. J.; Barabash, S.; Zhang, T. L. +5 more
We present the first observation of magnetic fluctuations consistent with short large-amplitude magnetic structures (SLAMS) in the foreshock of the planet Venus. Three monolithic magnetic field spikes were observed by the Venus Express on 11 April 2009. The structures were ∼1.5-11 s in duration, had magnetic compression ratios between ∼3 and 6, an…
Determining the axial direction of high-shear flux transfer events: Implications for models of FTE structure
Milan, S. E.; Fear, R. C.; Oksavik, K.
Flux transfer events are bursts of dayside reconnection, which give rise to local perturbations of the magnetic field that can be observed by spacecraft near the magnetopause. Although it is commonly accepted that flux transfer events are caused by reconnection, various models exist to explain their structure. A key difference between mechanisms i…
Identification of electron field-aligned current systems in Saturn's magnetosphere
Schippers, P.; André, N.; Gurnett, D. A. +3 more
Based on the analysis of 7 years of Cassini electron plasma spectrometer data near Saturn's equatorial plane, we computed the average directional electron current in the Northern and the Southern hemispheres separately. We determined the net current density by subtracting the downward electron current density (equator to the ionosphere) from the u…
A statistical study of energy release and transport midway between the magnetic reconnection and initial dipolarization regions in the near-Earth magnetotail associated with substorm expansion onsets
Paterson, W. R.; Miyashita, Y.; Saito, Y. +3 more
Our previous study showed that the energy release associated with substorm expansion onsets is the most significant midway between the magnetic reconnection and initial dipolarization regions (-12 > X > -18 RE in the premidnight sector) in the magnetotail. In the present paper, we have statistically studied the substorm-associated…