Lorentz force and energy source terms for the plane x = −15 Mm (see its photospheric trace C in Fig. 2). a) Lorentz force on the y-axis at t = 0 s (positive values are shown in red, and negative values are shown in blue), b) compression, c) advection, and d) radiative cooling at t = 0.23 s (positive values are indicated in dark orange, and negative values are shown in purple). The upper limit of the transition region is denoted with the solid black line.