A note on the relationship between net radiation and solar radiation

Linear relationships between daytime net radiation ( R n ) and solar radiation ( Q ) have been determined for West Africa and for selected stations throughout the world. For three West African stations. R n = 0·612 Q −28 And for fourteen stations throughout the world R n = 0·617 Q −24 Where R n and Q are in g cal cm −2 day −1 . The surfaces represented have albedos ranging from 0·20 to 0·30. On average, net radiation is 55 per cent of the solar radiation. Values for a heating coefficient β, inferred from the relationships, lie between 0·14 and 0·30. The results are not consistent with some previous work. The application of the relationship to estimating evaporation and potential evapotranspiration is discussed.