Cloud water content profiles derived from passive satellite data

This paper describes a technique to estimate the vertical profile of ice water content in cirrus clouds, and ice and liquid water contents in deep ice over water cloud systems from traditional passive satellite retrievals. Satellite imager retrievals of cloud optical thickness, cloud top and base height are used to constrain cloud type dependent climatological information on the vertical distribution of total cloud mass and phase partitioning derived from a combination of active sensor data, microwave radiometer data and cloud model simulations. When applied to MODIS data, the technique produces ice water content profiles that agree well with retrievals from CloudSat and CALIPSO data over a wide range of cloud conditions. Several months of MODIS data are analyzed to examine the global distribution of ice and liquid water content and water path produced with the new technique. These are compared to estimates made from other sensors using other methods. When applied to geostationary satellite data, the technique provides a four-dimensional depiction of cloud vertical structure and corroborates aircraft icing intensities reported by pilots indicating that the method has measurable skill in defining both the total mass, and in partitioning the liquid from ice in deep ice over water cloud systems. The goal of this work is to improve the accuracy and overall utility of passive satellite cloud retrievals for monitoring the cloud water budget for weather and climate applications.