Agile mapping of SIF and xCO2 from the upcoming OCO-3 mission will enable new carbon cycle science

Planned for launch in early 2019, the third Orbiting Carbon Observatory (OCO-3) will have unprecedented agility among greenhouse gas observing satellites allowing frequent regional mapping of column xCO2 and solar-induced chlorophyll fluorescence (SIF) for areas up to 100x100km with ground footprints of 2 by 3km. Due to its low-inclination orbit (51.6 degrees) aboard the International Space Station, it will also offer uniquely dense sampling in the tropics as well as temporal sampling throughout the day not possible from previous sun-synchronous polar-orbiting missions. Together, these features will enable a new set of science investigations on the patterns of carbon dioxide and photosynthesis on Earth; specifically, as it relates to growing urban populations and changing patterns of fossil fuel combustion, geogenic CO2 emissions as a potential early warning signal before volcanic eruptions, and understanding the diurnal relationship between SIF and photosynthesis.

OCO-3 will arrive at the ISS at particularly fortuitous time, considering the potential for synergistic measurements of ecosystem function, structure and composition from three other instruments recently launched or planned for launch to the ISS. The recently launched ECOSTRESS (ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station) instrument is measuring plant evapotranspiration through via its influence on canopy temperature. The GEDI (Global Ecosystem Dynamics Investigation) instrument, planned for launch in late 2018, is a geodetic-class LIDAR that will measure canopy heights and foliar vertical profiles to establish a baseline of vegetation structure and global terrestrial biomass. And planned for launch in early 2020, the Japanese HISUI visible-to-shortwave imaging spectrometer will enable a near-global mapping of plant functional traits.

Here we present on the status of the OCO-3 mission, the new science enabled by its unique agility/orbit, a particular focus on the development and simulated performance of its observing strategy regarding the selection and scheduling of OCO-3 area mapping targets, and the opportunities for synergism with its companion instruments on the ISS.