ABSTRACT
Net radiation (Rn) is the algebraic sum of the downwelling broadband solar, the same as GHI, also called shortwave (S↓), the downwelling broadband infrared, also called longwave (L↓), the upwelling broadband shortwave (S↑), and the upwelling broadband longwave radiation (L↑), that is,
R S S L Ln = ↓ − ↑ + ↓ − ↑ (11.1) Net radiation is the energy that evaporates water or sublimates ice, produces sen-
sible heat that raises the temperature of the atmosphere, and heats surface soil or water. A small amount of net energy is used to photosynthesize carbon dioxide and water into organic compounds, especially sugars, and oxygen in plants. Measuring the net energy with the highest accuracy is important because this is the energy that drives weather and climate.
