Search Publications
In situ optical measurements of Chang'E-3 landing site in Mare Imbrium: 1. Mineral abundances inferred from spectral reflectance
Xiao, Long; Di, Kaichang; Yuan, Ye +11 more
The visible and near-infrared imaging spectrometer on board the Yutu Rover of Chinese Chang'E-3 mission measured the lunar surface reflectance at a close distance (~1 m) and collected four spectra at four different sites. These in situ lunar spectra have revealed less mature features than that measured remotely by spaceborne sensors such as the Mo…
A new mechanism for OH vibrational relaxation leading to enhanced CO2 emissions in the nocturnal mesosphere
Sharma, Ramesh D.; Wintersteiner, Peter P.; Kalogerakis, Konstantinos S.
On the basis of experimental and theoretical studies, this paper proposes a new mechanism that contributes to nocturnal 4.3 µm CO2 emissions. It suggests that collisions of ground state O atoms with highly vibrationally excited OH(v), produced by the reaction of H with O3, remove a substantial fraction of the OH(v) vibrationa…
Identifying the source region of plasmaspheric hiss
Laakso, Harri; Masson, Arnaud; Escoubet, Philippe +4 more
The presence of the plasmaspheric hiss emission around the Earth has been known for more than 50 years, but its origin has remained unknown in terms of source location and mechanism. The hiss, made of whistler mode waves, exists for most of the time in the plasmasphere and is believed to control the radiation belt surrounding the Earth which makes…
An ionized layer in the upper atmosphere of Mars caused by dust impacts from comet Siding Spring
Gurnett, D. A.; Persoon, A. M.; Morgan, D. D. +4 more
We report the detection of a dense ionized layer in the upper atmosphere of Mars caused by the impact of dust from comet Siding Spring. The observations were made by the ionospheric radar sounder on the Mars Express spacecraft during two low-altitude passes approximately 7 h and 14 h after closest approach of the comet to Mars. During these passes…
The dayside reconnection voltage applied to Saturn's magnetosphere
Masters, A.
The ability of magnetic reconnection between interplanetary and planetary magnetic fields to drive a planetary magnetosphere can be quantified as the resulting voltage applied to the system. We present analytical model predictions of the dayside reconnection voltage at Saturn, a planet where solar wind driving has been the subject of debate. Model…
Nonlinear subcyclotron resonance as a formationmechanism for gaps in banded chorus
Gary, S. Peter; Fu, Xiangrong; Dong, Chuanfei +1 more
An interesting characteristic of magnetospheric chorus is the presence of a frequency gap at ω≃0.5Ωe, where Ωe is the electron cyclotron angular frequency. Recent chorus observations sometimes show additional gaps near 0.3Ωe and 0.6Ωe. Here we present a novel nonlinear mechanism for the formation of thes…
Magnetic forces associated with bursty bulk flows in Earth's magnetotail
Karlsson, Tomas; Nilsson, Hans; Hamrin, Maria +2 more
We present the first direct measurements of magnetic forces acting on bursty bulk flow plasma in the magnetotail. The magnetic forces are determined using Cluster multispacecraft measurements. We analyze 67 bursty bulk flow (BBF) events and show that the curvature part of the magnetic force is consistently positive, acting to accelerate the plasma…
Motion of reconnection region in the Earth's magnetotail
Nakamura, Rumi; Semenov, Vladimir S.; Nakamura, Takuma K. M. +1 more
We obtain the X-line velocity in the Earth's magnetotail for 24 reconnection events observed by the Cluster spacecraft between 2001 and 2005. The data set consists of 10 single X-lines and 14 X-lines from the time intervals of multiple reconnection. Except for two X-lines from multiple reconnection, all the X-lines move tailward (radial outward) a…
Near-Sun speed of CMEs and the magnetic nonpotentiality of their source active regions
Tiwari, Sanjiv K.; Winebarger, Amy R.; Venkatakrishnan, P. +3 more
We show that the speed of the fastest coronal mass ejections (CMEs) that an active region (AR) can produce can be predicted from a vector magnetogram of the AR. This is shown by logarithmic plots of CME speed (from the SOHO Large Angle and Spectrometric Coronagraph CME catalog) versus each of ten AR-integrated magnetic parameters (AR magnetic flux…
The effect of diamagnetic drift on motion of the dayside magnetopause reconnection line
Fear, R. C.; Marcucci, M. F.; Trenchi, L.
Magnetic reconnection at the magnetopause occurs with a large density asymmetry and for a large range of magnetic shears. In these conditions, a motion of the X line has been predicted in the direction of the electron diamagnetic drift. When this motion is super Alfvenic, reconnection should be suppressed. We analysed a large data set of Double St…