The correlated-k method and related methods for broadband radiation calculations

The fundamentals of radiation calculations in planetary atmospheres have been known for a long time, but the practical problems of calculating radiation over a broad spectral range both efficiently and accurately remain an area of active research. The Goody et al. paper of 1989 established a milestone in that long effort. Goody et al. highlighted attempts to formulate the problem in terms of a few absorption coefficients that could represent typically tens of thousands of coefficients in a rigorous line-by-line calculation. Here we provide a brief background, point out that the correlated-k method is a special case of a broader spectral mapping concept, and mention some new ideas that have emerged recently.