A Lidar Approach to Measure CO2 Concentrations from Space for the ASCENDS Mission

We report on a lidar approach to measure atmospheric CO2 column concentration being developed as a candidate for NASA’s ASCENDS mission. It uses a pulsed dual-wavelength lidar measurement based on the integrated path differential absorption (IPDA) technique. We demonstrated the approach using the CO2 measurement from aircraft in July and August 2009 over various locations. The results show clear CO2 line shape and absorption signals, which follow the expected changes with aircraft altitude from 3 to 13 km. The column absorption measurements show altitude dependence in good agreement with column number density estimates calculated from airborne in-situ measurements. The approaches for O2 measurements and for scaling the technique to space are discussed.