The GEOS-Carb modeling and assimilation system is an extension of the GEOS-5 general circulation model and data assimilation system developed at NASA's Global Modeling and Assimilation Office (GMAO). In particular, the Level 3 (L3) system processes retrievals of column-average carbon dioxide (XCO2) based on near-infrared radiance measurements from the Orbiting Carbon Observatory 2 (OCO-2) - the resulting L3 maps are the most complete and highest resolution assimilated picture of global CO2 yet. The extent of its coverage makes the L3 product a powerful tool for the evaluation of the satellite data against independent observations. The inverse modeling system, on the other hand, uses a separate ensemble square root filter to estimate global sources and sinks of CO2. Results show that OCO-2 observations are able to capture the broad spatial and temporal patterns of flux estimates, and are especially beneficial over regions poorly constrained by the existing ground-based monitoring network (for e.g., South America). As the OCO-2 data matures, we will refine both the L3 and the L4 system and explore specific cases where we observe anomalies in the XCO2 distribution, for example, the Tropical and the Southern Ocean sectors. Such anomalies indicate the possibility of previously unobserved fluxes, transport variability, and/or impact of the current El Nino conditions on land- /ocean-atmosphere carbon exchanges.