Search Publications
Saturn's quasiperiodic magnetohydrodynamic waves
Coates, A. J.; Dougherty, M. K.; Hospodarsky, G. B. +11 more
Quasiperiodic ∼1 h fluctuations have been recently reported by numerous instruments on board the Cassini spacecraft. The interpretation of the sources of these fluctuations has remained elusive to date. Here we provide an explanation for the origin of these fluctuations using magnetometer observations. We find that magnetic field fluctuations at h…
Cluster observations of reflected EMIC-triggered emission
Santolík, O.; Cornilleau-Wehrlin, N.; Masson, A. +2 more
On 19 March 2001, the Cluster fleet recorded an electromagnetic rising tone on the nightside of the plasmasphere. The emission was found to propagate toward the Earth and toward the magnetic equator at a group velocity of about 200 km/s. The Poynting vector is mainly oblique to the background magnetic field and directed toward the Earth. The propa…
Mass wasting on Phobos triggered by an evolving tidal environment
Shi, X.; Oberst, J.; Willner, K.
The Martian moon Phobos is experiencing orbital decay, increasing tidal forces, and possible disruption in the near future. We suggest that this changing dynamic tidal environment has contributed to resurfacing of the odd-shaped small moon. We investigated mass wasting features in craters using high-resolution images acquired by the Mars Express o…
Cone angle control of the interaction of magnetic clouds with the Earth's bow shock
Escoubet, C. P.; Kilpua, E. K. J.; Turc, L. +2 more
We study the interaction of magnetic clouds (MCs) with the near-Earth environment. Recent works suggest that the bow shock crossing may modify significantly the magnetic structure of an MC, and thus its ability to drive geomagnetic storms. This change is largely controlled by the bow shock configuration, which depends on the upstream interplanetar…
Generation of He+ and O+ EMIC waves by the bunch distribution of O+ ions associated with fast magnetosonic shocks in the magnetosphere
Lee, L. C.; Lee, K. H.
Electromagnetic ion cyclotron (EMIC) waves are often observed in the magnetosphere with frequency usually in the H+ and He+ cyclotron bands and sometimes in the O+ band. The temperature anisotropy, caused by injection of energetic ions or by compression of magnetosphere, can efficiently generate H+ EMIC …
Dipolarization front and current disruption
Lui, A. T. Y.
The modification of current density on the dawn-dusk cross section of the magnetotail with the earthward approach of a dipolarization front (DF) is examined through the recently published results of a three-dimensional (3-D) particle-in-cell (PIC) simulation. It is found that the current density intensifies by 37% abruptly within 1.5 ion gyrotime …
A case study of a density structure over a vertical magnetic field region in the Martian ionosphere
Gurnett, D. A.; Lundin, R.; Morgan, D. D. +3 more
One of the discoveries made by the radar sounder on the Mars Express spacecraft is the existence of magnetically controlled structures in the ionosphere of Mars, which result in bulges in the ionospheric electron density contours. These bulges lead in turn to oblique echoes, which show up as hyperbola-shaped features in the echograms. A hyperbola-…
Two interacting X lines in magnetotail: Evolution of collision between the counterstreaming jets
Retinò, Alessandro; Nakamura, Rumi; Nakamura, Takuma +5 more
We study the process of collision between the counterstreaming jets flowing out from two reconnection sites in the Earth's magnetotail. The X lines, bracketing the region of jets collision, were passing by two Cluster probes successively in tailward direction. Two probes observed two different stages of the collision process. At the jets collision…
Thin energetic O+ layer embedded in the magnetotail reconnection current sheet observed by Cluster
Sun, W. J.; Fu, S. Y.; Zong, Q. G. +6 more
In the classical picture of the magnetotail current sheet, the current carriers are mainly ions that undergo nonadiabatic motions. Oxygen ions could contribute a thicker current sheet than the protons due to their large gyroradii. In this paper, however, we report a thin energetic O+ layer embedded in the magnetotail proton current shee…
Ducted electromagnetic waves in the Martian ionosphere detected by the Mars Advanced Radar for Subsurface and Ionosphere Sounding radar
Huang, Qian; Zhang, Jie; Orosei, Roberto +1 more
In the data of the Mars Advanced Radar for Subsurface and Ionosphere Sounding on board the European Space Agency (ESA) mission Mars Express (MEX), a distinctive type of signals (called the "epsilon signature"), which is similar to that previously detected during radio sounding of the terrestrial F region ionosphere, is found. The signature is inte…