Collisionless plasma processes at magnetospheric boundaries: Role of strong nonlinear wave interactions
S. Savina, E. Amatab, L. Zelenyiaj, C. Wangc, H. Lic, B. Tangc, G. Pallocchiab, J. Safrankovad, Z. Nemecekd, A. S. Sharmae, F. Marcuccib, L. Kozakf, J. L. Rauchg, V. Budaeva,h, J. Bleckii, L. Legena, M. Nozdracheva
aSpace Research Institute Russian Academy of Sciences, 117997 Moscow, Russia
bINAF-Istituto di Astrofisica e Planetologia Spaziali, 00133 Roma, Italy
cNational Space Science Center, Chinese Academy of Sciences, 100190 Beijing, China
dCharles University, Prague, 1636 Czech Republic
eUniversity of Maryland, College Park, 20742 Chesapeake, USA
fKyiv Taras Shevchenko University, 01601 Kyiv, Ukraine
gLaboratory of Physics and Chemistry of the Environment and Space, 45071 Orleans, France
hNRC Kurchatov Institute, 123182 Moscow, Russia
iSpace Research Center, 57622 Warsaw, Poland
jMoscow Physical Technical Institute, 12795 Moscow, Russia
Abstract
This Letter presents an analysis of the sunward Poynting flux throughout magnetosheath and
foreshock (directly measured by INTERBALL-1, CLUSTER-4 and DOUBLE STAR TC1) and its
correlation and bi-correlation with the dynamic pressure of the solar plasma flow. It demonstrates,
for the first time, that perturbations, caused by the resonances in the magnetospheric boundary
layers, propagate upstream towards the bow shock as the short impulses of the sunward Poynting flux,
which excite the strongest 3-wave resonances. They are initiated in the foreshock and regulate the bow
shock surface oscillations. Another interaction zone near the magnetopause assists plasma flow extra
deflection and acceleration around the magnetopause. At the outer boundary of stagnant cusp the
turbulent barrier can separate the flowing and stagnant plasmas namely by the 3-wave cascades.
So, both experiment and MHD modeling demonstrate the leading role of the discovered waves and
nonlinear processes in the collisionless interaction of the plasma flow and magnetic barrier.