MODIS-Derived Value-Added Climatology of Maritime Cloud Liquid Water Path Conserving Solar Reflectance, Collection 5 & Collection 6

A dataset is generated from a method to retrieve distributions of cloud liquid water path over partially cloudy scenes. The method was introduced in Foster et al. (2011), which described the theory and provided test cases. It has been applied to both MODIS Collection 5 cloud products, resulting in a value-added data set containing adjusted distributions of cloud liquid water path over a decade in length for marine liquid cloud for both Aqua and Terra. This method adjusts horizontal distributions of cloud optical properties to be more consistent with observed visible reflectance and is especially useful in areas where cloud optical retrievals fail or are considered low quality. Results show that the fit methodology is able to reduce bias between observed visible scene reflectance and that derived from optical retrievals by up to 3% mean improvement using Collection 5. The level of improvement is dependent on several factors including seasonality, viewing geometry, cloud fraction and cloud heterogeneity. The initial application to MODIS Collection 6 shows significant adjustments to the distributions of cloud liquid water path signifying potential improvements in the amounts of quality cloud optical retrievals. Potential uses of this data set include model validation and facilitating satellite record inter-comparison studies. This work seeks to explore the applications of the Foster et al. methodology and the effects of changes from MODIS Collection 5 to Collection 6.