Search Publications
The termination shock near 35° latitude
Burlaga, L. F.; Sheeley, N. R.; Wang, Y. -M. +1 more
The termination shock moves outwards and inwards over timescales of a solar cycle in response to the variations in the average solar wind speed. The amplitude is greater than 50 AU near 35° latitude; the maximum (minimum) distance occurs during the rising (declining) phase of the solar cycle. Shock parameters are distinctly different when the shoc…
Oblique propagation of 30 s period fast magnetosonic foreshock waves: A Cluster case study
Balogh, A.; Dandouras, I.; Eastwood, J. P. +2 more
It is accepted that the 30 s period Ultra-Low-Frequency waves observed in the terrestrial foreshock are generated by backstreaming ions through the ion-ion right hand instability. However, such waves are generally observed to propagate obliquely to the field, in direct contrast to theoretical predictions of parallel propagation. A case study, base…
Transient ion beamlet injections into spatially separated PSBL flux tubes observed by Cluster-CIS
Lundin, R.; Dandouras, I.; Klecker, B. +8 more
Ion measurements from Cluster-CIS were used to characterize and interpret the signatures of PSBL energy-dispersed ions and their fine structure. On 14 February 2001, several ion injections were encountered by SC 1 and SC 3, separated by ~530 km, during an outbound orbit at 4.5 RE. Both satellites recorded the same ion structures. The en…
Cluster observations of complex 3D magnetic structures at the magnetopause
Fedorov, A.; Budnik, E.; Balogh, A. +7 more
On June 30, 2001, around 0530 UT, Cluster was moving along the magnetopause with spacecraft on both sides of the discontinuity. The configuration was `quasi-ideal' with magnetic field and plasma flow almost aligned in the magnetosheath and nearly anti-parallel to the magnetospheric field. Cluster observed several perturbations with leading and tra…
Chemical composition of Titan's haze: Are PAHs present?
McKay, Christopher P.; Toon, Owen B.; Trainer, Melissa G. +4 more
Previous laboratory studies of haze aerosols analogous to those in Titan's atmosphere have shown evidence of the formation of polycyclic aromatic hydrocarbons (PAHs). If present, PAHs may provide a mechanism for both particle formation and nitrogen incorporation. We have conducted new experiments simulating Titan haze production using an Aerosol M…
Two examples of magnetic clouds with double rotations observed by the Ulysses spacecraft
Forsyth, R. J.; Rees, A.
A survey of Ulysses magnetometer data has been carried out between Oct 1990 (launch) and Apr 2003 (just after the second northern polar pass) cataloguing magnetic cloud (MC) signatures, i.e., a smooth magnetic field rotation and enhanced magnetic field magnitude. After confirming that each of these events was a true MC by checking for a low proton…
Discrete modes and turbulence in a wave-driven strongly magnetized plasma
Matthaeus, William H.; Lanzerotti, Louis J.; Dmitruk, Pablo
We show the coexistence of discrete modes and turbulence in numerical experiments of magnetohydrodynamics with a strong background magnetic field. The particular system we consider is a model of an open magnetic region which we have previously used in coronal heating studies. In the simulations shown here, Alfven waves at discrete frequencies with…
Cluster observations of velocity space-restricted ion distributions near the plasma sheet
Lundin, R.; Sauvaud, J. -A.; Dandouras, I. +15 more
We present Cluster ion observations obtained at 18 RE in the magnetotail on 1 October 2001. According to a recent analysis, the quartet encountered a reconnection region and a tailward-moving neutral line. We examine in detail selected 3-D ion distributions, which through much of the hour following 0925 UT were non-gyrotropic. B-perpend…
CLUSTER observations of lower hybrid waves excited at high altitudes by electromagnetic whistler mode signals from the HAARP facility
Pickett, J. S.; Inan, U. S.; Platino, M. +3 more
We report new observations from the CLUSTER spacecraft of strong excitation of lower hybrid (LH) waves by electromagnetic (EM) whistler mode waves at altitudes >=20,000 km outside the plasmasphere. Previous observations of this phenomenon occurred at altitudes <=7000 km. The excitation mechanism appears to be linear mode coupling in the pres…
The dependence of Langmuir wave amplitudes on position in Earth's foreshock
Gurnett, D. A.; Balogh, A.; Pickett, J. S. +3 more
We present the first results of Langmuir wave observations in the foreshock from the Cluster WBD Plasma Wave Receiver. When the data were binned by distance to the foreshock boundary, the Langmuir wave amplitude probability distributions followed the log-normal statistics predicted by stochastic growth theory for all regions of the foreshock. The …