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

Abstract

Past studies have demonstrated that synoptically active weather systems play an important role in the spatial and temporal variations of atmospheric carbon dioxide (CO2) within and above the planetary boundary layer. For the first time, we investigate the spatial variability of column‐averaged dry‐air mole fractions of normalCnormalO2 ${\mathrm{C}\mathrm{O}}_{2}$ (normali.normale.,normalXnormalCnormalO2 $\mathrm{i}.\mathrm{e}.,{\mathrm{X}\mathrm{C}\mathrm{O}}_{2}$) due to the impact of synoptic scale transport using retrievals from the Orbiting Carbon Observatory‐2 (OCO‐2) for 66 summer cold front passage cases over the conterminous U.S. and Mexico from 2015 to 2019. normalXnormalCnormalO2 ${\mathrm{X}\mathrm{C}\mathrm{O}}_{2}$ differences across cold fronts in summer were found to be in good agreement with observations obtained from the Atmospheric Carbon and Transport (ACT‐America) field campaign, though with a reduced magnitude due the flat averaging kernel representing fairly uniform vertical sensitivity in the troposphere as opposed to in situ normalCnormalO2 ${\mathrm{C}\mathrm{O}}_{2}$ measurements. OCO‐2 observed normalXnormalCnormalO2 ${\mathrm{X}\mathrm{C}\mathrm{O}}_{2}$ frontal differences are statistically distinct from north‐south normalXnormalCnormalO2 ${\mathrm{X}\mathrm{C}\mathrm{O}}_{2}$ climatological spatial variations on similar spatial‐scales on synoptically benign days, implying that the frontal passages contribute to enhanced normalXnormalCnormalO2 ${\mathrm{X}\mathrm{C}\mathrm{O}}_{2}$ spatial contrasts. An exploratory analysis finds no evidence of a linkage between the temperature differences and normalXnormalCnormalO2 ${\mathrm{X}\mathrm{C}\mathrm{O}}_{2}$ differences, but a more thorough exploration is left as future work.

Seasonal and Diurnal Variations in XCO2 Characteristics in China as Observed by OCO‐2/3 Satellites: Effects of Land Cover and Local Meteorology

“…First of all, satellite data gaps caused by narrow swaths as well as cloud and aerosol effects on retrieval algorithms may have a probable impact on the current findings. Future research could focus on fusing long‐term satellite data with machine learning techniques to map contiguous XCO 2 (M. Zhang & Liu, 2023; Y. Wang, Yuan, et al., 2023). Secondly, the investigation was predicated on the straightforward notion that the XCO 2 transport terms average out to be low levels, which discounts the strong modulation by synoptic and mesoscale systems (Keppel‐Aleks et al., 2011; Torres et al., 2019).…”

“…Variations in long‐lived atmospheric CO 2 reflect the combined result of local anthropogenic CO 2 emissions (Nassar et al., 2021), natural dynamics of the terrestrial biosphere (Keppel‐Aleks et al., 2011), and transport by weather systems (Keppel‐Aleks et al., 2012; Parazoo et al., 2008; Torres et al., 2019; Q. Wang, Crowell, et al., 2023). Indeed, several studies have highlighted the prominent contribution of large‐scale atmospheric transport to diurnal XCO 2 variability (Keppel‐Aleks et al., 2011; Torres et al., 2019).…”

“…Variations in long-lived atmospheric CO 2 reflect the combined result of local anthropogenic CO 2 emissions (Nassar et al, 2021), natural dynamics of the terrestrial biosphere (Keppel-Aleks et al, 2011), and transport by weather systems (Keppel-Aleks et al, 2012;Parazoo et al, 2008;Torres et al, 2019;Q. Wang, Crowell, et al, 2023).…”