Global carbon monoxide vertical distributions from spaceborne high-resolution FTIR nadir measurements

[摘要] This paper presents the first global distributions of CO vertical profilesretrieved from a thermal infrared FTS working in the nadir geometry. It isbased on the exploitation of the high resolution and high quality spectrameasured by the Interferometric Monitor of Greenhouse gases (IMG) which flewonboard the Japanese ADEOS platform in 1996-1997. The retrievals areperformed with an algorithm based on the Optimal Estimation Method (OEM) andare characterized in terms of vertical sensitivity and error budget. It isfound that most of the IMG measurements contain between 1.5 and 2.2independent pieces of information about the vertical distribution of CO fromthe lower troposphere to the upper troposphere-lower stratosphere (UTLS). Theretrievals are validated against coincident NOAA/CMDL in situ surfacemeasurements and NDSC/FTIR total columns measurements. The retrieved globaldistributions of CO are also found to be in good agreement with thedistributions modeled by the GEOS-CHEM 3D CTM, highlighting the ability ofIMG to capture the horizontal as well as the vertical structure of the COdistributions.

[学科分类] 大气科学