Atmospheric Greenhouse Gas Distributions Across Weather Systems: Results from the Summer 2016 ACT-America Field Campaign (Invited Presentation)

Incomplete knowledge of both greenhouse gas (GHG) sources and sinks, and atmospheric transport of these gases limits our ability to use atmospheric observations to infer surface fluxes.  The existing long-term observational network is too sparse to disentangle these two factors.  The Atmospheric Carbon and Transport (ACT) - America mission aims to improve our understanding of both transport and fluxes of GHGs via spatially dense, airborne observations spanning a range of midlatitude weather conditions.  The first ACT-America field campaign was conducted in July and August of 2016.  Remote and in situ observations were collected with two aircraft across fronts and during fair weather conditions across three regions of the eastern United States. We present a first synthesis of these observations.  We describe the distribution of GHGs, related trace gases and atmospheric properties across a number of frontal structures, and present a first comparison to numerical models of these systems, working towards an improved understanding of how midlatitude cyclones redistribute GHGs in space and time.  We also present observations of the evolution of the atmospheric boundary layer and its GHG mole fractions during fair weather conditions, and draw inferences concerning regional fluxes over domains of order 10⁵ km².  We look ahead to upcoming field campaigns, and the application of our findings to date to future atmospheric inverse GHG flux estimates.