Visit the Land Data Assimilation Systems homepage Rain and snowfall are key components of land surface models, including the Land Data Assimilation Systems (LDAS), which integrate satellite and ground-based observational data to generate estimates of soil moisture, soil temperature, evapotranspiration and runoff. Scientists use this and other models to study surface features and how they change due to manmade and natural conditions such as urbanization and erosion. The Global LDAS (GLDAS) uses TRMM precipitation data in numerous investigations into how water and energy cycle through natural...