A comprehensive plan for studying the carbon cycle from space

During 2001, a team of scientists and engineers from NASA Goddard Space Flight Center (GSFC) led a planning activity for future studies of the sources, sinks, and transport of carbon in the atmosphere, on land, and in the oceans. This study was conducted at the request of NASA headquarters. Members of the Earth sciences community and representatives from other NASA centers and headquarters participated in a series of workshops to further refine the science questions, determine the required measurements, and identify gaps in our current measurements suite. Three critical gaps were identified: (1) global time series of CO/sub 2/ atmosphere-surface exchange, (2) ecosystems carbon storage due to land biomass and its change as well as the carbon consequences of disturbance and (3) measurements of critical biochemicals mediating global ocean surface layer uptake and export of carbon. The observations required to fill these gaps were also defined and include: (1) satellite-based observations of column and profile carbon dioxide concentration, (2) reprocessing of the historic land satellite record to track land use changes over time and quantify their carbon consequences, (3) satellite measurements of chlorophyll and related organic and inorganic compounds in the coastal and upper deep ocean. The status of observation technology to support these new measurements was investigated through detailed science and engineering studies, and developed into nominal missions in the Goddard Integrated Mission Design Center. Technologies are currently not at a high enough technology readiness level to support all of these missions. A program of technology development with properties was recommended. Algorithm development, historical data analysis, in situ and aircraft measurements, field campaigns, calibration and validation requirements, numerical model and data assimilation development, and data synthesis were also included in the recommendations. The various elements were costed, prioritized, and provided to NASA headquarters for consideration. This material was presented to OMB and subsequent activities have benefited from this planning effort.