Estimating the net-radiation flux

✍ Scribed by E.T. Linacre

• Publisher: Elsevier Science
• Year: 1968
• Weight: 619 KB
• Volume: 5
• Category: Article
• ISSN: 0002-1571
• DOI: 10.1016/0002-1571(68)90022-8

✦ Synopsis

A major influence controlling the water loss from irrigated crops is the netradiation intensity Q,, but measurements of this are not normally available, and so attempts are often made to deduce it from other climatic data, such as the solarradiation. Here it is shown that the relationship between net and solar-radiation intensities depends on the degree of cloudiness and the ambient temperature. By making appropriate assumptions, a series of expressions for Q,, is derived, with decreasing accuracy but increasing simplicity of estimation. It appears that clouds lower the net-radiation intensity when it exceeds a critical value in the region of 0.02 cal./cm 2 min, but increase it when the intensity is lower.