The MODIS cloud radiative kernel decomposition of SW ERFaci requires implementation of the new joint histogram diagnostics in a GCM, as well as a Python script that performs the decomposition. To update your GCM to include the new r_e-CWP joint histogram diagnostics, the source file that interfaces with COSP should be modified (view minimum code changes here). The code to perform the decomposition of SW ERFaci from ice clouds can be found here, and the code to conduct the decomposition for liquid clouds can be found here. The COSP code changes necessary for the MODIS joint histograms should be available in the master branch or tags>=v2.1.8