How do cloud-types affect inter-satellite biases?

Cloud feedbacks remain the largest source of uncertainty in projections of future climate. Even on regional scales, it remains unclear how specific cloud types respond to climate forcings, and how particular cloud types contribute to the overall cloud feedback. While the current observational database is not of sufficient length or homogeneity to directly constrain the global cloud feedback, it may be possible to carefully construct a cloud-type database long enough and consistent enough to constrain the components of the feedback due to individual cloud types. In the present study, we attempt to analyze inter-satellite radiance biases from High Resolution Infrared Radiation Sounders (HIRS) aboard NOAA polar-orbiters as a function of cloud type, using nearly simultaneous nadir cloud type information from the Clouds from AVHRR Extended (CLAVR-x) dataset. Understanding cloud-type specific biases may aid in the inter-calibration of HIRS channels. In addition, the radiance statistics themselves may be used to constrain climate model simulations.