Space-based CO2 LAS Measurements for ASCENDS

NASA is investigating the feasibility of an active, laser-based remote sensing mission to enhance the understanding of the role of carbon dioxide (CO2) in the global carbon cycle. In response to the National Research Council (NRC) decadal survey report, Earth Science and Applications from Space: National Imperatives for the Next Decade and Beyond, the NASA Science Mission Directorate has conduced system studies to investigate the feasibility of implementing the Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) mission. ASCENDS would extend the observational capabilities of current passive remote sensing missions by providing day/night, all-latitude, all-season column integrated measurements of CO2 and the required ancillary measurements necessary for quantifying the global distribution of terrestrial and oceanic sources and sinks of CO2. This paper discusses the results of the ASCENDS mission study, including the key mission design constraints and assumptions, measurement performance goals, assessments of the scientific and technical feasibility of the mission concept, with emphasis on a continuous wave (CW) Laser Absorption Spectrometer (LAS) measurement approach.