Systematic deviations of clear sky atmospheric thermal radiation from predictions of empirical formulae

Four replicated measurements of atmospheric thermal radiation were obtained every half‐hour of seven clear days during February at Phoenix, Arizona. All indicated the existence of systematic deviations from the predictions of empirical formulae. By invoking an explanation for the existence of such deviations recently given by Paltridge (1970), the times of occurrence of these deviations could be predicted quite accurately.