Detailed understanding of the impact of frontal systems on the spatiotemporal variability of atmosphere-ecosystem carbon dioxide (CO₂) exchange and on spatial variability of atmospheric GHGs on regional scales is needed for forward model evaluation purposes. The first Atmospheric Carbon and Transport (ACT) – America airborne field campaign (15 July- 31 Aug, 2016) was conducted across the three regions in the eastern United States to study the transport and fluxes of atmospheric carbon dioxide and methane. One primary goal is to measure how weather systems transport greenhouse gases (GHGs). High resolution remote and in-situ airborne observations were collected with two aircrafts (NASA’s C-130 and B-200) during diverse meteorological conditions.

We hypothesize that typical synoptic weather events perturb the spatial heterogeneity in the atmospheric GHG concentrations both horizontally and vertically across the frontal boundaries. Preliminary data analyses suggest that ACT data sets contain unique results and the flight patterns designed during frontal passage days have the potential to explore GHG variability along different atmospheric layers from ~200 m to 9000 m. Key findings demonstrating the modification of the CBL and FT exchange processes as the front propagates over the experimental domain will be presented. For instance, we will show how the CO₂ and CH₄ spatial variability get modify during a situation for cold fronts with prefrontal troughs and wind shifts. We also explore the ACT-America data set to obtain some insights into how CBL regimes and synoptic scale transport interact and influence the spatial variability in the vertical CO₂ and CH₄ gradients.