Data assimilation is a formalized process for bringing together sources of information in a unified system. At the highest level there are two sources of information in Earth-science data assimilation, a physical-based prediction model and geophysical observations. The impact of a particular type of observation is dependent on model quality, analysis method, observation quality control, data usage, and system interfaces.

This talk will highlight the impact of new observing systems on the quality of assimilated data sets. Of particular interest will be systematic improvements that extend beyond the particular impact that an observing system was designed to address. For instance, ocean-surface wind measurements provide definitive improvement to weather forecasts as well as better estimates of boundary layer processes that are important for trace gas transport. The impact of ocean surface winds, rainfall data, and new sources of temperature and constituent information will be discussed.