The conceptual and scientific motivation for the Global Ecosystem Dynamics Investigation

Abstract:

The Global Ecosystem Dynamics Investigation is a NASA mission that will produce the first comprehensive and high-resolution measurements of ecosystem structure from space. The instrument is a multi-beam waveform LiDAR sensor that will orbit on the International Space Station, eventually producing > 15 billion measurements of canopy height in the world’s temperate and tropical forests over the nominal one-year mission life. This talk will provide an overview of the design, calibration and validation of the mission, and will focus on describing the scientific and conceptual motivation. GEDI was conceived to answer persistent questions about the role of forests in the global carbon cycle. How large is the contribution of deforestation to annual fluxes of CO₂ to the atmosphere? What will be the capacity of forests to absorb CO₂ in the future? What fraction of fluxes of carbon to the atmosphere is through large infrequent disturbance events, and what does this suggest about the ability of scientists to obtain unbiased estimates of these fluxes using atmospheric inversions, eddy covariance techniques, or inventories from permanent plot networks? All of these questions are united by the need for extensive, high-resolution measurements of canopy height that GEDI will provide.