The ﹩{H}_{\mathrm{tr}}/{H}_{\mathrm{ph}}﹩ of various M dwarfs and the Sun as a function of ﹩{p}_{\mathrm{tr}}/{p}_{\mathrm{ph}}﹩. The simulation results shown here are obtained by setting v_ph/v_conv = 1 and ﹩\mathrm{ln}(\overline{B}/{B}_{\mathrm{ph}})=-3,-4,-5,-6﹩. The red rectangle represents the range of observed plasma pressure in the solar spicule (Alissandrakis et al. 2018; Shimojo et al. 2020) and that of the observed spicule height (Pereira et al. 2012; Zhang et al. 2012).