10. The dusty case: dust mixing by convection Dust spreads over whole con- vection layer after 3 hours from the time when the dust injection started (LT=15:00). Horizontal contrast of radiative heating associated with the dust distribution has negligible effect on the morphology of convection. Fig.7: Time development of distributions of potential temperature deviation from the horizontal mean (left) and dust mixing ratio (right kg/kg) (LT = 12:00 to 15:00 of 1st day).