Seminar

Abstract

This presentation will discuss progress in measuring atmospheric CO₂ and CH₄ with lidar from the ground and from aircraft and their application to greenhouse gas investigations. Significant progress has been made over the past few years in developing lidar approaches and demonstrating their performance in making remote high-precision measurements of CO₂ and CH₄. Several different lidar techniques are in various stages of development with goals to make remote CO₂ measurements with better than 1 ppm sensitivity. Ground-based lidars have demonstrated CO₂ profiling capabilities and horizontally averaged CO₂ and CH₄ column measurements. These lidars have the potential of being able to investigate the spatial and temporal variability of CO₂ fluxes to complement in-situ measurements on towers and aircraft.

Airborne lidars are currently being evaluated for nadir column CO₂ measurements from the aircraft to the Earth's surface or cloud tops. Evaluations are being conducted to assess their performance and to support the development of future space missions. Results from recent airborne tests have demonstrated the ability to make high-precision CO₂ column measurements beneath the aircraft flight track. Airborne CH₄ column lidars are also under development. A CO₂ measuring space mission for ESA called A-SCOPE was studied recently. A NASA CO₂ mission called ASCENDS and a French/German CH₄ mission called MERLIN are in their early stages of development. This presentation will survey the previous work and these plans for the future.