Time evolution of the cool and dense solar prominence matter above the chromosphere boundary (above 2 Mm from the bottom boundary) taken below a threshold temperature of 5 × 10⁴ K, and denser than 10⁻¹¹ kg m⁻³. The dashed line represents the phase of the initial decrease of mass of the cool and dense volume in the solar prominence due to the merging of the cool dense material into the chromosphere boundary. The dotted line represents the phase where the prominence material rises towards the top boundary with a significant loss of the prominence material. The solid line represents the evolution at time = 429.37 s (see Figure 1 (middle)).