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Evaluation of Regional CO2 Mole Fractions in the ECMWF CAMS Real-Time Atmospheric Analysis and NOAA CarbonTracker Near-Real-Time Reanalysis With Airborne Observations From ACT-America Field Campaigns

Chen, Hans W. LU ; Zhang, Lily N. ; Zhang, Fuqing ; Davis, Kenneth J. ; Lauvaux, Thomas ; Pal, Sandip ; Gaudet, Brian and DiGangi, Joshua P. (2019) In Journal of Geophysical Research: Atmospheres 124(14). p.8119-8133
Abstract

This study systematically examines the regional uncertainties and biases in carbon dioxide (CO2) mole fractions from two of the state-of-the-art global CO2 analysis products, namely, the Copernicus Atmosphere Monitoring Service (CAMS) real-time atmospheric analysis from the European Centre for Medium-Range Weather Forecasts (ECMWF) and the CarbonTracker Near-Real-Time (CT-NRT) reanalysis from the National Oceanic and Atmospheric Administration (NOAA), by evaluation against hundreds of hours of airborne in situ measurements from the summer 2016 and winter 2017 Atmospheric Carbon and Transport (ACT)-America field campaigns. Both the CAMS and CT-NRT analyses agree reasonably well with the independent ACT-America... (More)

This study systematically examines the regional uncertainties and biases in carbon dioxide (CO2) mole fractions from two of the state-of-the-art global CO2 analysis products, namely, the Copernicus Atmosphere Monitoring Service (CAMS) real-time atmospheric analysis from the European Centre for Medium-Range Weather Forecasts (ECMWF) and the CarbonTracker Near-Real-Time (CT-NRT) reanalysis from the National Oceanic and Atmospheric Administration (NOAA), by evaluation against hundreds of hours of airborne in situ measurements from the summer 2016 and winter 2017 Atmospheric Carbon and Transport (ACT)-America field campaigns. Both the CAMS and CT-NRT analyses agree reasonably well with the independent ACT-America airborne CO2 measurements in the free troposphere, with root-mean-square deviations (RMSDs) between analyses and observations generally between 1 and 2 ppm but show considerably larger uncertainties in the atmospheric boundary layer where the RMSDs exceed 8 ppm in the lowermost 1 km of the troposphere in summer. There are strong variations in accuracy and bias between seasons, and across three different subregions in the United States (Mid-Atlantic, Midwest, and South), with the largest uncertainties in the Mid-Atlantic region in summer. Overall, the RMSDs of the CAMS and CT-NRT analyses against airborne data are comparable to each other and largely consistent with the differences between the two analyses. The current study provides uncertainty estimates for both analysis products over North America and suggests that these two independent estimates can be used to approximate regional CO2 analysis uncertainties. Both statistics are important in future studies in quantifying the uncertainties in regional CO2 mole fraction and flux estimates.

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organization
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type
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publication status
published
subject
in
Journal of Geophysical Research: Atmospheres
volume
124
issue
14
pages
15 pages
publisher
Wiley-Blackwell Publishing Ltd
external identifiers
  • scopus:85069913261
ISSN
2169-897X
DOI
10.1029/2018JD029992
language
English
LU publication?
yes
id
196a840a-5f74-4e81-9a12-504aa51f95e2
date added to LUP
2019-11-13 16:17:53
date last changed
2020-01-13 02:31:33
@article{196a840a-5f74-4e81-9a12-504aa51f95e2,
  abstract     = {<p>This study systematically examines the regional uncertainties and biases in carbon dioxide (CO<sub>2</sub>) mole fractions from two of the state-of-the-art global CO<sub>2</sub> analysis products, namely, the Copernicus Atmosphere Monitoring Service (CAMS) real-time atmospheric analysis from the European Centre for Medium-Range Weather Forecasts (ECMWF) and the CarbonTracker Near-Real-Time (CT-NRT) reanalysis from the National Oceanic and Atmospheric Administration (NOAA), by evaluation against hundreds of hours of airborne in situ measurements from the summer 2016 and winter 2017 Atmospheric Carbon and Transport (ACT)-America field campaigns. Both the CAMS and CT-NRT analyses agree reasonably well with the independent ACT-America airborne CO<sub>2</sub> measurements in the free troposphere, with root-mean-square deviations (RMSDs) between analyses and observations generally between 1 and 2 ppm but show considerably larger uncertainties in the atmospheric boundary layer where the RMSDs exceed 8 ppm in the lowermost 1 km of the troposphere in summer. There are strong variations in accuracy and bias between seasons, and across three different subregions in the United States (Mid-Atlantic, Midwest, and South), with the largest uncertainties in the Mid-Atlantic region in summer. Overall, the RMSDs of the CAMS and CT-NRT analyses against airborne data are comparable to each other and largely consistent with the differences between the two analyses. The current study provides uncertainty estimates for both analysis products over North America and suggests that these two independent estimates can be used to approximate regional CO<sub>2</sub> analysis uncertainties. Both statistics are important in future studies in quantifying the uncertainties in regional CO<sub>2</sub> mole fraction and flux estimates.</p>},
  author       = {Chen, Hans W. and Zhang, Lily N. and Zhang, Fuqing and Davis, Kenneth J. and Lauvaux, Thomas and Pal, Sandip and Gaudet, Brian and DiGangi, Joshua P.},
  issn         = {2169-897X},
  language     = {eng},
  month        = {01},
  number       = {14},
  pages        = {8119--8133},
  publisher    = {Wiley-Blackwell Publishing Ltd},
  series       = {Journal of Geophysical Research: Atmospheres},
  title        = {Evaluation of Regional CO<sub>2</sub> Mole Fractions in the ECMWF CAMS Real-Time Atmospheric Analysis and NOAA CarbonTracker Near-Real-Time Reanalysis With Airborne Observations From ACT-America Field Campaigns},
  url          = {http://dx.doi.org/10.1029/2018JD029992},
  doi          = {10.1029/2018JD029992},
  volume       = {124},
  year         = {2019},
}