TY - JOUR
T1 - Validation of regional CO2 mole fractions in the ECMWF MACC real-time analysis and NOAA CarbonTracker Near-Real Time reanalysis with airborne observations from ACT-America Field campaigns
AU - Chen, Hans
AU - Pal, Sandip
PY - 2019/6/15
Y1 - 2019/6/15
N2 - 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 CopernicusAtmosphere Monitoring Service (CAMS) real-time atmospheric analysis from the European Centre forMedium-RangeWeather Forecasts (ECMWF) and the CarbonTracker Near-Real-Time (CT-NRT)reanalysis from the National Oceanic and Atmospheric Administration (NOAA), by evaluation againsthundreds of hours of airborne in situ measurements from the summer 2016 and winter 2017 AtmosphericCarbon and Transport (ACT)-America field campaigns. Both the CAMS and CT-NRT analyses agreereasonably 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 and2 ppm but show considerably larger uncertainties in the atmospheric boundary layer where the RMSDsexceed 8 ppm in the lowermost 1 km of the troposphere in summer. There are strong variations in accuracyand 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, theRMSDs of the CAMS and CT-NRT analyses against airborne data are comparable to each other and largelyconsistent with the differences between the two analyses. The current study provides uncertainty estimatesfor both analysis products over North America and suggests that these two independent estimates can beused to approximate regional CO2 analysis uncertainties. Both statistics are important in future studies inquantifying the uncertainties in regional CO2 mole fraction and flux estimates.
AB - 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 CopernicusAtmosphere Monitoring Service (CAMS) real-time atmospheric analysis from the European Centre forMedium-RangeWeather Forecasts (ECMWF) and the CarbonTracker Near-Real-Time (CT-NRT)reanalysis from the National Oceanic and Atmospheric Administration (NOAA), by evaluation againsthundreds of hours of airborne in situ measurements from the summer 2016 and winter 2017 AtmosphericCarbon and Transport (ACT)-America field campaigns. Both the CAMS and CT-NRT analyses agreereasonably 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 and2 ppm but show considerably larger uncertainties in the atmospheric boundary layer where the RMSDsexceed 8 ppm in the lowermost 1 km of the troposphere in summer. There are strong variations in accuracyand 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, theRMSDs of the CAMS and CT-NRT analyses against airborne data are comparable to each other and largelyconsistent with the differences between the two analyses. The current study provides uncertainty estimatesfor both analysis products over North America and suggests that these two independent estimates can beused to approximate regional CO2 analysis uncertainties. Both statistics are important in future studies inquantifying the uncertainties in regional CO2 mole fraction and flux estimates.
M3 - Article
JO - Journal of Geophysical Research-Atmospheres
JF - Journal of Geophysical Research-Atmospheres
ER -