Magnetospheric Multiscale observations of Earth’s oblique bow shock reformation by foreshock ultra‐low frequency waves

Author(s):  
Terry Z. Liu ◽  
Yufei Hao ◽  
Lynn B. Wilson ◽  
Drew L. Turner ◽  
Hui Zhang
1997 ◽  
Vol 20 (4-5) ◽  
pp. 703-706 ◽  
Author(s):  
K. Meziane ◽  
C. Mazelle ◽  
C. d'Uston ◽  
H. Rème ◽  
R.P. Lin ◽  
...  

1995 ◽  
Vol 22 (2) ◽  
pp. 81-84 ◽  
Author(s):  
T. Sugiyama ◽  
T. Terasawa ◽  
H. Kawano ◽  
T. Yamamoto ◽  
S. Kokubun ◽  
...  

2013 ◽  
Vol 31 (8) ◽  
pp. 1387-1395 ◽  
Author(s):  
A. P. Dimmock ◽  
M. A. Balikhin ◽  
S. N. Walker ◽  
S. A. Pope

Abstract. Low frequency waves in the foot of a supercritical quasi-perpendicular shock front have been observed since the very early in situ observations of the terrestrial bow shock (Guha et al., 1972). The great attention that has been devoted to these type of waves since the first observations is explained by the key role attributed to them in the processes of energy redistribution in the shock front by various theoretical models. In some models, these waves play the role of the intermediator between the ions and electrons. It is assumed that they are generated by plasma instability that exist due to the counter-streaming flows of incident and reflected ions. In the second type of models, these waves result from the evolution of the shock front itself in the quasi-periodic process of steepening and overturning of the magnetic ramp. However, the range of the observed frequencies in the spacecraft frame are not enough to distinguish the origin of the observed waves. It also requires the determination of the wave vectors and the plasma frame frequencies. Multipoint measurements within the wave coherence length are needed for an ambiguous determination of the wave vectors. In the main multi-point missions such as ISEE, AMPTE, Cluster and THEMIS, the spacecraft separation is too large for such a wave vector determination and therefore only very few case studies are published (mainly for AMPTE UKS AMPTE IRM pair). Here we present the observations of upstream low frequency waves by the Cluster spacecraft which took place on 19 February 2002. The spacecraft separation during the crossing of the bow shock was small enough to determine the wave vectors and allowed the identification of the plasma wave dispersion relation for the observed waves. Presented results are compared with whistler wave dispersion and it is shown that contrary to previous studies based on the AMPTE data, the phase velocity in the shock frame is directed downstream. The consequences of this finding for both types of models that were developed to explain the generation of these waves are discussed.


2003 ◽  
Vol 51 (11) ◽  
pp. 693-702 ◽  
Author(s):  
M.A. Balikhin ◽  
O.A. Pokhotelov ◽  
S.N. Walker ◽  
M. Andre

2020 ◽  
Author(s):  
Riku Jarvinen ◽  
Esa Kallio ◽  
Tuija I. Pulkkinen

<p>We study the solar wind interaction with Venus and Mercury in a 3-dimensional global hybrid simulation where ions are treated as particles and electrons are a charge-neutralizing fluid. We concentrate on the formation of large-scale ultra-low frequency (ULF) waves in ion foreshocks and their dependence on the solar wind and interplanetary magnetic field conditions. The ion foreshock forms in the upstream region ahead of the quasi-parallel bow shock, where the angle between the shock normal and the magnetic field is smaller than about 45 degrees. The magnetic connection with the bow shock allows backstreaming of the solar wind ions leading to the formation of the ion foreshock. This kind of beam-plasma configuration is a source of free energy for the excitation of plasma waves. The foreshock ULF waves convect downstream with the solar wind flow and encounter the bow shock. We compare the waves between Venus and Mercury, and analyze the coupling of the ULF waves with the planetary ion acceleration at Venus.</p> <p>References:</p> <p>Jarvinen R., Alho M., Kallio E., Pulkkinen T.I., 2020, Oxygen Ion Escape From Venus Is Modulated by Ultra-Low Frequency Waves, Geophys. Res. Lett., 47, 11, doi:10.1029/2020GL087462</p> <p>Jarvinen R., Alho M., Kallio E., Pulkkinen T.I., 2020, Ultra-low frequency waves in the ion foreshock of Mercury: A global hybrid modeling study, Mon. Notices Royal Astron. Soc., 491, 3, 4147-4161, doi:10.1093/mnras/stz3257</p>


1995 ◽  
Vol 15 (8-9) ◽  
pp. 285-296 ◽  
Author(s):  
C.T Russell ◽  
M.H Farris

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