On The Propagation And Modulation Of Electrostatic Solitary Waves Observed Near The Magnetopause On Cluster

J.S. Pickett (1) , I. W. Christopher (1) , B. Grison (2) , S. Grimald (3) , O. Santolik (4) , Pierrette Décréau (5) , B. Lefebvre (6) , M. J. Engebretson (7) , L. M. Kistler (6) , D. Constantinescu , L.‐j. Chen (6) , Y. Omura (8) , G. S. Lakhina (9) , D. A. Gurnetta (1) , Nicole Cornilleau-Wehrlin (10) , A.N. Fazakerley (11) , I. Dandouras , E. Lucek (12)

1 Department of Physics and Astronomy [Iowa City]
2 IAP - Institute of Atmospheric Physics [Prague]
3 UT - Université de Toulouse
4 Faculty of Mathematics and Physics [Praha/Prague]
5 LPC2E - Laboratoire de Physique et Chimie de l'Environnement et de l'Espace
6 UNH - University of New Hampshire
7 Department of Physics [Minneapolis]
8 RISH - Research Institute for Sustainable Humanosphere
9 IIG - Indian Institute of Geomagnetism [Navi Mumbai, India]
10 USN - Unité Scientifique de la Station de Nançay
11 MSSL - Mullard Space Science Laboratory
12 Imperial College London

We present the results of a study of Electrostatic Solitary Waves (ESWs) in which propagation of a series of noncyclical ESWs is observed from one Cluster spacecraft to another over distances as great as tens of km and time lags as great as a few tens of ms. This propagation study was conducted for locations near the magnetopause on the magnetosheath side. Propagation was found primarily toward the earth with speeds on the order of 1500 to 2400 km/s. The sizes of the ESWs obtained from these velocities were on the order of 1 km along the magnetic field direction and several tens of km perpendicular. These results are consistent with measurements on single spacecraft in which the ESW propagation is observed with time lags of only ∼0.1 ms. Our results thus show the stability of ESWs over time periods much greater than their own characteristic pulse durations of a few 100s of microseconds. We present also the results of a study of ESW modulation at the magnetopause on the earthward side. We found that ESWs were modulated at ∼1.3 Hz, consistent with a Pc1 wave which was observed concurrently. During this time, tens of eV electron beams are present. We propose a Buneman type instability in which the E'''' component of the Pc1 waves provides a mechanism for accelerating electrons, resulting in the generation of the ESWs modulated at the Pc1 frequency.

Keywords: Magnetopause; Electrostatic Solitary Waves; Pc1 Waves; Buneman Instability PACS: 9430ch; 9405Fg; 9430Ms; 9405Pt; 9430cq

Domains: Sciences of the Universe [physics]

J.S. Pickett, I. W. Christopher, B. Grison, S. Grimald, O. Santolik, et al.. On The Propagation And Modulation Of Electrostatic Solitary Waves Observed Near The Magnetopause On Cluster. AIP Conference Proceedings, 2011, Sani Resort, Greece. pp.115-124, ⟨10.1063/1.3544316⟩. ⟨insu-02927249⟩