Toward Quantifying the Science Benefit of Spaceborne Aerosol-Cloud-Ocean Lidar for Climate Science

The CALIOP lidar on the CALIPSO satellite has proven the value of active remote sensing for climate science. Along with other A-Train measurements, CALIOP has enabled the first global estimate of all-sky aerosol radiative forcing, quantified radiative effects of aerosols above low clouds, provided information needed to improve model characterization of cloud thermodynamic phase, contributed to more accurate global estimates of downward radiative fluxes, and provided new insight on the annual cycle of phytoplankton blooms. While huge progress has been made with the 12 years of A-Train observations, the 2017-2027 Decadal Survey for Earth Science and Applications from Space identified several climate objectives that require aerosol/cloud/ocean lidar observations. In this presentation, we discuss advances in lidar capability that will be useful in meeting those Decadal Survey objectives. Also required will be observations from additional instruments, and determining the optimum balance in capability between instruments for a cost-capped mission will be a challenge. A logical and transparent way to assess the science benefit of competing mission architectures with different instrument capabilities is through the Value Framework approach described in the National Academy of Sciences Report "Continuity of NASA Earth Observations from Space". We provide a brief overview of this approach and how it might be applied to meeting climate-related objectives identified in the Decadal Survey.