On a certain day, towering cumulus clouds are unable to penetrate above the 500 mb level, where the temperature is -20C, because of the presence of a weakly stable layer where the environment lapse rate is 5C/km. If these clouds are seeded with silver iodide so that all of the liquid water in them (1 g/m^3) freezes, by how much will the tops of the cumulus cloud rise ? [ Note: from the skew T- In p chart, the saturated adiabatic lapse rate at 500 mb is around 6C/km. Hint:focus on the thermodynamics at cloud top.]