The Atmospheric Pathfinder Data Set is becoming a mature and popular resource for satellite cloud climate studies. One of the key activities of PATMOS-x is the use of physically-based algorithms to derive consistent time series from the 15 sensors that contribute to the POES/AVHRR data record. In particular, PATMOS-x employs innovative infrared (IR) radiative transfer approaches in several key algorithms. In particular, the use of these approaches is generating new information about the long-term properties of cirrus clouds. PATMOS-x has now been extended to include data from MODIS and this talk will present some of the newer findings about clouds revealed by the additional spectral information provided by MODIS.