Determination of Ice Water Path Over the ARM SGP Using Combined Surface and Satellite Datasets

Global information of cloud ice water path (IWP) is urgently needed for testing of global climate models (GCMs) and other applications. Accurate quantification of the IWP is essential for characterizing the hydrological and radiation budget. For example, the reflection of shortwave radiation by ice clouds reduces the solar energy reaching the earth’s surface. Ice clouds can also trap the longwave radiation emitted from surface, resulting in less radiation to space in comparison with clear-sky conditions. The net radiative flux at surface depends on accurate description of IWP. Determination of cloud IWPs is often complicated because of cloud overlap. Satellite retrievals of IWP are still in the developing stages, and tend to have large uncertainties (e.g., factor of 2 or more).