The O2 airglow retrievals: implications to mesospheric temperature and greenhouse gas remote sensing from space

Kang Sun,  University at Buffalo,  kangsun@buffalo.edu (Presenter)
Mahdi Yousefi,  University at Buffalo,  mahdiyou@buffalo.edu
Christopher Chan Miller,  Harvard University,  cmiller@cfa.harvard.edu
Kelly Chance,  Harvard-Smithsonian Center for Astrophysics,  kchance@cfa.harvard.edu
Iouli Gordon,  Harvard-Smithsonian Center for Astrophysics,  igordon@cfa.harvard.edu
Xiong Liu,  Harvard-Smithsonian Center for Astrophysics,  xliu@cfa.harvard.edu
Christopher Sioris,  Environment and Climate Canada,  christopher.sioris@canada.ca
Steven Wofsy,  Harvard University,  wofsy@g.harvard.edu

Earth airglow emission spectra for the O2 A band at 760 nm and the O2 “singlet Delta” band at 1270 nm have been observed by various sensors. Spectroscopic simulations using upper state populations and HITRAN database successfully reconstruct the SCIAMACHY airglow spectra for both bands with excellent accuracy. The accurate knowledge of airglow spectrum enables retrieval of the airglow volume emission rate and temperature. The retrieval of the O2 singlet Delta airglow provides mesospheric temperature profiles (60-90 km) with uncertainty lower than 3 K, and the O2 A band airglow retrieval provides temperature profiles at the mesopause and lower thermosphere. Temperatures derived independently by these two bands are in good agreement in the mesopause region, where both airglows are strong and generally free from interferences. The O2 singlet Delta band has long been deemed unusable to quantify O2 columns, a critical component for spaceborne greenhouse gas remote sensing, due to the intense airglow. We found that when properly included, the airglow spectral feature can be adequately separated from total O2 absorption (mean bias <0.1%) at the spectral resolution of modern spaceborne spectrometers.

Poster: Poster_Sun__110_25.pdf 

Presentation Type: Poster

Session: 2.2a Retrieval algorithms and methods for inter-instrument and product Cal/Val

Session Date: Tuesday (6/15) 9:45 AM