Articles | Volume 10, issue 7
Research article
19 Jul 2017
Research article |  | 19 Jul 2017

A climate-scale satellite record for carbon monoxide: the MOPITT Version 7 product

Merritt N. Deeter, David P. Edwards, Gene L. Francis, John C. Gille, Sara Martínez-Alonso, Helen M. Worden, and Colm Sweeney

Abstract. The MOPITT (Measurements of Pollution in the Troposphere) satellite instrument has been making observations of atmospheric carbon monoxide since 2000. Recent enhancements to the MOPITT retrieval algorithm have resulted in the release of the version 7 (V7) product. Improvements include (1) representation of growing atmospheric concentrations of N2O, (2) use of meteorological fields from the MERRA-2 (Modern-Era Retrospective Analysis for Research and Applications) reanalysis for the entire MOPITT mission (instead of MERRA), (3) use of the MODIS (Moderate-Resolution Imaging Spectroradiometer) Collection 6 cloud mask product (instead of Collection 5), (4) a new strategy for radiance-bias correction and (5) an improved method for calibrating MOPITT's near-infrared (NIR) radiances. Statistical comparisons of V7 validation results with corresponding V6 results are presented, using aircraft in situ measurements as the reference. Clear improvements are demonstrated for V7 products with respect to overall retrieval biases, bias variability and bias drift uncertainty.

Short summary
This manuscript describes the methods used for deriving the latest version 7 product for atmospheric carbon monoxide (CO) from measurements made by the MOPITT (Measurements of Pollution in the Troposphere) satellite instrument. Comparisons of MOPITT-retrieved CO vertical profiles with in situ data measured from aircraft are also presented, and they demonstrate clear improvements relative to earlier MOPITT products. The new CO product is appropriate for a wide variety of applications.