Acoustic waves in the solar atmosphere. IX - Three minute pulsations driven by shock overtaking

Computations are presented showing that short-period acoustic waves with periods less than 40 sec can generate, by the process of shock overtaking, 3-min type first-overtone pulsations of the solar chromosphere. It is suggested that 3-min pulsations generated by acoustic waves may be an explanation for the observed Ca II K(2V) cell grains. It is shown that shock overtaking occurs only if the wavelength of the shock wave is small enough, such that the excess speed of the faster moving shock is able to catch up with the slower shock within the chromosphere. It is suggested that the shock overtaking pulsation process, by feeding energy into long-period waves may be very important for the driving of mass loss in red giant stars.