On radiational cooling computations in clouds.

Expressions are derived for the cooling or heating rates for clouds in which the condensed phase is either ice or water. Values are computed for ice and water clouds over a reasonable temperature range for pressures of 1000, 500, and 200 mb. The importance is shown of adequately allowing for the latent load in computations of radiative cooling or heating rates based on measurements of radiative divergence in clouds. It is shown that, other things being equal, the effect of the latent load is always greatest at low levels and higher temperatures.