Overarching goal: Create Climatological Lidar Ratio Maps for CALIPSO - Since CALIPSO is an elastic backscatter lidar, it is necessary to select a priori aerosol lidar ratios prior to computing extinction profiles. - Presently, the CALIPSO lidar ratio selection process uses a single lidar ratio for each of the 7 CALIPSO aerosol types in the troposphere. - Consequently, regional and seasonal variability of the lidar ratio is very limited in the present CALIPSO algorithm. - Here, we describe an approach for creating new climatological lidar ratio maps for each of the CALIPSO aerosol types using MODIS-CALIPSO constrained retrievals and global model simulations. - The purpose is to eventually replace the seven single-valued lidar ratios for the CALIPSO types with latitude- and longitude-dependent maps for each of the seven types.