On Estimating Insolation over the Ocean

Abstract

The results of two studies that reported procedures for estimating insulation at sea are summarized. The insulation under clear skies may be computed reliably with a formula derived from the Smithsonian Meteorological Tables, using a transmission coefficient of 0.7, or with a formula derived by Lumb. For estimating the reduction of insolation by clouds, the factor 1−0.62C+0.0019α is suggested, where C is cloud amount in tenths and α is noon solar attitude. Random errors of estimate within 95% confidence limits are less than 10% for mean monthly data and are about ±20% for weekly periods.