Carbon Dioxide Near Infrared Absorption Line Shapes for Atmospheric Remote Sensing

College Of William And Mary, Williamsburg VA

Investigators

Abstract

This award supports measurements of spectroscopic properties of carbon dioxide (CO2), the principal anthropogenic greenhouse gas. The results of this work will improve the precision of remote sensing techniques for CO2, which will be used in the near future to quantify its spatial and temporal variations. Our ability to forecast long-term climate changes depends on a detailed understanding of the carbon budget and accurate predictions of future atmospheric concentrations of CO2. Near infrared spectroscopic techniques provide excellent opportunities for measuring CO2 with the required precision; however, measurements at this level of precision require knowledge of the temperature-dependent spectroscopic line shape and pressure shift parameters with unprecedented accuracy. These parameters will be determined from a multi-spectrum analysis of high-resolution spectra recorded at the Kitt Peak National Solar Observatory. Investigators from the College of William and Mary, in collaboration with the NASA Jet Propulsion Laboratory (JPL) and the Kitt Peak National Solar Observatory, will carry out this work. They will demonstrate the retrieval of column CO2 with a precision of 0.3% using high-resolution solar spectra from the Table Mountain Facility Fourier-Transform Ultraviolet Spectrometer (FTUVS), combined with a new parameterization of CO2 near infrared line shapes and pressure shifts. This award will support undergraduate students at the College of William and Mary and provide them with training in state-of-the-art spectroscopic techniques, as well as an appreciation of issues in global climate change.