Land surface net radiation

Abstract

Land surface all-wave net radiation (Rn) is one of the most important parameters in various applications, such as physical, agronomical, and biological applications, and remote sensing makes it possible to map Rn globally. This article presents various remote sensing methods for estimating Rn, roughly consisting of three categories: parameterization, hybrid, and data assimilation. The first two methods are commonly used and can be further divided into component-based and direct estimation. The details and the characteristics of each of these methods are described. Three existing remotely sensed Rn products (CERES-SYN, GEWEX-SRN, and ISCCP-FD) and a newly developed GLASS Rn product are introduced. The algorithms for producing these products and the product inter-comparisons are provided. Finally, the global Rn spatio-temporal variations during recent decades are analyzed, and the corresponding driving factors are also discussed.