Examining CO₂ Model Observation Residuals Using ACT‐America Data

Abstract

background conditions. Results revealed systematic differences in atmospheric transport, most pronounced in the warm and cold sectors of synoptic systems, highlighting the importance of transport for 2 CO E residuals. While CT could reproduce the principal 2 CO Edynamics associated with synoptic systems, WRF showed a clearer distinction for 2 CO E differences across fronts. Variograms were used to quantify spatial correlation of residuals and showed characteristic residual length scales of approximately 100-300 km. Our findings suggest that inclusion of synoptic weather-dependent and non-Gaussian error structure may benefit inversion systems. GERKEN ET AL.

Airborne Lidar Measurements of XCO2 in Synoptically Active Environment and Associated Comparisons With Numerical Simulations

“…Using airborne in situ measurements of CO 2 fields obtained during the ACT‐America RFs, Gerken et al. ( 2021 ) exploited the performance of both mesoscale (WRF‐Chem) and global scale (CT) models using identical surface fluxes and found reasonable agreement with observations in all four seasons. Additionally, for frontal RFs, Zhang et al.…”

“…Previously, using ground-based XCO 2 measurements at TCCON site (Park Falls, Wisconsin), Keppel-Aleks et al (2012) found that XCO 2 variability even at one location were primarily driven by combined impact of regional-scale fluxes and atmospheric dynamics and also attributed the large-scale gradients of XCO 2 to synoptic-scale meteorological processes. Using airborne in situ measurements of CO 2 fields obtained during the ACT-America RFs, Gerken et al (2021) exploited the performance of both mesoscale (WRF-Chem) and global scale (CT) models using identical surface fluxes and found reasonable agreement with observations in all four seasons. Additionally, for frontal RFs, Zhang et al (2022) also found that OCO-2 MIP models were capable of simulating observed CO 2 frontal contrasts with varying degrees of success in summer and spring, and frequent underestimation of frontal contrasts in winter and autumn.…”

“…CT outputs are available at 3-hourly temporal resolution at 1⁰ × 1⁰ spatial resolution and provides the carbon surface fluxes from the terrestrial biosphere, oceans, fossil fuels, wildfires, and atmospheric CO 2 mole fractions (Jacobson et al, 2007(Jacobson et al, , 2020. Additional details on the WRF-Chem model setup and performance can be found elsewhere Gerken et al, 2021;Samaddar et al, 2021). WRF-Chem was run at 27-km covering most of North America from 1 June 2016 to 30 June 2019.…”

Atmospheric Variations in Summertime Column Integrated CO2 on Synoptic Scales Over the U.S.

“…ACT‐America measurements helped to quantify atmospheric transport uncertainties (Davis et al., 2021; Feng et al., 2019; Gerken et al., 2021; Zhang et al., 2022). Within the ACT‐America project, five airborne campaigns across three regions in the Eastern and Midwestern United States were conducted to study the transport and fluxes of atmospheric carbon dioxide and methane (Pal & Davis, 2021).…”

“…Parazoo et al (2008) used combinations of simulations and observations to decompose the components of the PBL 𝐴𝐴 CO2 budget in the midlatitudes and found that the horizontal advection contributes to 60%-70% of 𝐴𝐴 CO2 daily variations on average in PBL, and thus dominates the variability seen in frontal gradients of 𝐴𝐴 CO2 . ACT-America measurements helped to quantify atmospheric transport uncertainties (Davis et al, 2021;Feng et al, 2019;Gerken et al, 2021;Zhang et al, 2022). Within the ACT-America project, five airborne campaigns across three regions in the Eastern and Midwestern United States were conducted to study the transport and fluxes of atmospheric carbon dioxide and methane .…”