Details:

Journal Title:
Atmospheric Chemistry and Physics
Personal Author:
Chevallier, Frédéric ; Remaud, Marine ; O'Dell, Christopher W. ; Baker, David ; Peylin, Philippe ; ... More +
Chevallier, Frédéric ; Remaud, Marine ; O'Dell, Christopher W. ; Baker, David ; Peylin, Philippe ; Cozic, Anne Less -
NOAA Program & Office:
CIRA (Cooperative Institute for Research in the Atmosphere)
Description:
We study an ensemble of six multi-year global Bayesian carbon dioxide (CO2) atmospheric inversions that vary in terms of assimilated observations (either column retrievals from one of two satellites or surface air sample measurements) and transport model. The time series of inferred annual fluxes are first compared with each other at various spatial scales. We then objectively evaluate the small inversion ensemble based on a large dataset of accurate aircraft measurements in the free troposphere over the globe, which are independent of all assimilated data. The measured variables are connected with the inferred fluxes through mass-conserving transport in the global atmosphere and are part of the inversion results. Large-scale annual fluxes estimated from the bias-corrected land retrievals of the second Orbiting Carbon Observatory (OCO-2) differ greatly from the prior fluxes, but are similar to the fluxes estimated from the surface network within the uncertainty of these surface-based estimates. The OCO-2-based and surface-based inversions have similar performance when projected in the space of the aircraft data, but the relative strengths and weaknesses of the two flux estimates vary within the northern and tropical parts of the continents. The verification data also suggest that the more complex and more recent transport model does not improve the inversion skill. In contrast, the inversion using bias-corrected retrievals from the Greenhouse Gases Observing Satellite (GOSAT) or, to a larger extent, a non-Bayesian inversion that simply adjusts a recent bottom-up flux estimate with the annual growth rate diagnosed from marine surface measurements both estimate much different fluxes and fit the aircraft data less. Our study highlights a way to rate global atmospheric inversions. Without any general claim regarding the usefulness of all OCO-2 retrieval datasets vs. all GOSAT retrieval datasets, it still suggests that some satellite retrievals can now provide inversion results that are, despite their uncertainty, comparable with respect to credibility to traditional inversions using the accurate but sparse surface network and that are therefore complementary for studies of the global carbon budget.
Keywords:
[+]
Atmospheric Chemistry Carbon Dioxide Mathematical Models
Source:
Atmospheric Chemistry and Physics, 19(22), 14233-14251
DOI:
https://doi.org/10.5194/acp-19-14233-2019
Document Type:
Journal Article
License:
https://creativecommons.org/licenses/by/4.0/
Rights Information:
CC BY
Compliance:
Library
Main Document Checksum:
[+]
urn:sha256:3677e9a20865bc5e826456fc881424a0d353bbd10605ca11db36417847d3ca8a
Download URL:
https://repository.library.noaa.gov/view/noaa/51400/noaa_51400_DS1.pdf
File Type:

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