@article{72ab506c0fe34459bf2016ba56945110,
title = "Toward a chemical reanalysis in a coupled chemistry-climate model: An evaluation of MOPITT CO assimilation and its impact on tropospheric composition",
abstract = "We examine in detail a 1 year global reanalysis of carbon monoxide (CO) that is based on joint assimilation of conventional meteorological observations and Measurement of Pollution in The Troposphere (MOPITT) multispectral CO retrievals in the Community Earth System Model (CESM). Our focus is to assess the impact to the chemical system when CO distribution is constrained in a coupled full chemistry-climate model like CESM. To do this, we first evaluate the joint reanalysis (MOPITT Reanalysis) against four sets of independent observations and compare its performance against a reanalysis with no MOPITT assimilation (Control Run). We then investigate the CO burden and chemical response with the aid of tagged sectoral CO tracers.We estimate the total tropospheric CO burden in 2002 (from ensemble mean and spread) to be 371 ± 12%Tg for MOPITT Reanalysis and 291 ± 9%Tg for Control Run. Our multispecies analysis of this difference suggests that (a) direct emissions of CO and hydrocarbons are too low in the inventory used in this study and (b) chemical oxidation, transport, and deposition processes are not accurately and consistently represented in the model. Increases in CO led to net reduction of OH and subsequent longer lifetime of CH4 (Control Run: 8.7 years versus MOPITT Reanalysis: 9.3 years). Yet at the same time, this increase led to 5-10% enhancement of Northern Hemisphere O3 and overall photochemical activity via HOx recycling. Such nonlinear effects further complicate the attribution to uncertainties in direct emissions alone. This has implications to chemistry-climate modeling and inversion studies of longer-lived species.",
author = "B. Gaubert and Arellano, {A. F.} and J. Barr{\'e} and Worden, {H. M.} and Emmons, {L. K.} and S. Tilmes and Buchholz, {R. R.} and F. Vitt and K. Raeder and N. Collins and Anderson, {J. L.} and C. Wiedinmyer and {Martinez Alonso}, S. and Edwards, {D. P.} and Andreae, {M. O.} and Hannigan, {J. W.} and C. Petri and K. Strong and N. Jones",
note = "Funding Information: The authors acknowledge the strong support of the European Commission, Airbus, and the Airlines (Lufthansa, Air France, Austrian, Air Namibia, Cathay Pacific, and China Airlines so far) who carry the MOZAIC or IAGOS equipment and perform the maintenance since 1994. MOZAIC is presently funded by INSU-CNRS (France), M?t?o-France, CNES, Universit? Paul Sabatier (Toulouse, France), and Research Center J?lich (FZJ, J?lich, Germany). IAGOS has been and is additionally funded by the EU projects IAGOS-DS and IAGOS-ERI. The MOZAIC-IAGOS data are available via CNES/CNRS-INSU Ether website http://www.pole-ether.fr. The data used in this publication were obtained as part of the Network for the Detection of Atmospheric Composition Change (NDACC) and are publicly available (see http://www.ndacc.org). The NCAR FTS observation program at Thule, Greenland, is supported under contract by the National Aeronautics and Space Administration (NASA). The Thule project is also supported by the NSF Office of Polar Programs (OPP). We wish to thank the Danish Meteorological Institute for support at Thule. The FTS measurements and analysis at Toronto were supported by NSERC, the Canadian Space Agency, and Environment Canada. The measurement program at Wollongong has been supported by the Australian Research Council for many years, most recently by grants DP110101948 and LE0668470. SMOCC was funded by the European Commission, the Max Planck Society, the Fundac?o de Amparo ? Pesquisa do Estado de S?o Paulo, and the Conselho Nacional de Desenvolvimento Cient?fico (Instituto do Mil?nio LBA). Computing resources were provided by the Climate Simulation Laboratory at NCAR's Computational and Information Systems Laboratory (CISL), sponsored by the National Science Foundation and other agencies. We would like to acknowledge high-performance computing support from Yellowstone (ark:/85065/d7wd3xhc) provided by NCAR's Computational and Information Systems Laboratory, sponsored by the National Science Foundation [Computational and Information Systems Laboratory,]. The CESM project is supported by the National Science Foundation and the Office of Science (BER) of the U.S. Department of Energy. The NCAR MOPITT project is supported by NASA's Earth Observing System Program. The National Center for Atmospheric Research is sponsored by the National Science Foundation. Any opinions, findings, and conclusions or recommendations expressed in this publication are those of the author and do not necessarily reflect the views of the National Science Foundation. A.F.A. acknowledges NASA supports under grants NNX13AK24G and NNX14AN47G. Publisher Copyright: {\textcopyright} 2016. American Geophysical Union. All Rights Reserved.",
year = "2016",
doi = "10.1002/2016JD024863",
language = "English (US)",
volume = "121",
pages = "7310--7343",
journal = "Journal of Geophysical Research: Atmospheres",
issn = "2169-897X",
number = "12",
}