Representing clouds in global climate models has long been a struggle for researchers because models lack the spatial resolution to fully represent clouds. Clouds move, blend and shift in the sky, making it difficult to track and understand their effects on climate change. Satellite cloud observations are helpful to test models' validity by using actual climate data; however, satellites can only offer a certain perspective because they pass areas at specified intervals. Researchers at Lawrence Livermore National Laboratory, in collaboration with scientists worldwide, have developed a software tool called the Cloud-Feedback-Model Intercomparison Project Observation Simulator Package (COSP) to bridge the gap between satellite data and climate modeling. COSP enables the comparison of models with observations from six satellite platforms including passive and active sensors. COSP facilitates a more rapid improvement of climate models and it will ultimately reduce uncertainty in climate predictions. COSP is now used world-wide by most of the major models for climate and weather prediction and will play a vital role in the evaluation of models that will be reviewed by the Intergovernmental Panel on Climate Change Fifth Assessment Report.

COSP is a community tool that is distributed under the BSD license. It can be downloaded from the CFMIP website.