Assessment of MISR and MODIS cloud top heights through intercomparison with a back-scattering lidar at SIRTA

One year of back-scattering lidar cloud boundaries and optical depth were analysed for coincident inter-comparison with the latest processed versions of the NASA-TERRA MISR stereo and MODIS CO(2)-slicing operational cloud top heights. Optically thin clouds were found to be accurately characterised by the MISR cloud top height product as long as no other cloud was present at lower altitude. MODIS cloud top heights were generally found within the cloud extent retrieved by lidar; agreement improved as cloud optical depth increased and when CO(2)-slicing was the only technique used for the retrieval. The difference between Lidar and MISR cloud top heights was found to lie between - 0.1 and 0.4 km for low clouds and between 0.1 and 3.1 km for high clouds. The difference between Lidar and MODIS cloud top heights was found to lie between - 1.2 and 1.5 km for low clouds and between - 1.4 and 2.7 km for high clouds.