• three-dimensional electrostatic solitary wave;
  • bow shock;
  • nonlinear structure


[1] Several cases of short-time durational large-amplitude three-dimensional (3-D) electrostatic solitary waves (ESWs) are observed within the transition layer of the terrestrial bow shock by THEMIS/E. Their pulse width is small (0.8–2 ms), but the amplitude is large (greater than 100 mV/m), suggesting a very strong potential drop. Two character angles (θ1 and θ2) are defined to describe the 3-D characteristics of the ESWs, and it returns results as 76° > θ1 > 27° and 70° > θ2 > 20°, suggesting that the electron potential holes are mainly in 3-D ellipsoid sphere-shaped structure, including “pancake-shaped” structure and “sphere-shaped” structure. None of the theories commonly used to describe ESWs adequately address these pancake-shaped and sphere-shaped three-dimensional structures observed in the terrestrial bow shock, where ωce < < ωpe in a weak magnetized plasma. The observation of large three-dimensional ESWs with different spatial structures during small time interval suggests anisotropic distribution of electric potentials and presents evidence of complex wave fluctuation within the bow shock.