Publication Date:
2018-06-13
Description:
Although the O 2 a 1 Δ g band has long been used in ground-based greenhouse gas remote sensing to constrain the light path, it is challenging for nadir spaceborne sensors due to strong mesosphere/stratosphere airglow. Spectroscopic simulations using upper state populations successfully reconstruct the airglow spectra with excellent agreement with SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY limb observations (residual root-mean-square 〈0.7%). The accurate knowledge of airglow spectrum enables retrieval of O 2 (a 1 Δ g ) number density, volume emission rate, and temperature. For nadir spaceborne observations, the a 1 Δ g airglow will lead to a negative bias of ∼10% to O 2 column, if not considered. However, when properly included, the airglow spectral feature can be adequately separated from O 2 absorption (mean bias 〈0.1%) at the spectral resolution of modern spaceborne spectrometers. ©2018. American Geophysical Union. All Rights Reserved.
Print ISSN:
0094-8276
Electronic ISSN:
1944-8007
Topics:
Geosciences
,
Physics
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