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We present the results of analytical modelling of fast-modemagnetohydrodynamic wave propagation near a 2D magnetic null point. We considerboth a linear wave and a weak shock and analyse their behaviour in cold andwarm plasmas. We apply the nonlinear geometrical acoustics method based on theWentzel-Kramers-Brillouin approximation. We calculate the wave amplitude, usingthe ray approximation and the laws of solitary shock wave damping. We find thata complex caustic is formed around the null point. Plasma heating isdistributed in space and occurs at a caustic as well as near the null point dueto substantial nonlinear damping of the shock wave. The shock wave passesthrough the null point even in a cold plasma. The complex shape of the wavefront can be explained by the caustic pattern.

Modelling the Propagation of a Weak Fast-Mode MHD Shock Wave near a 2D Magnetic Null Point Using Nonlinear Geometrical Acoustics