Detecting policy-relevant greenhouse gas emission changes with atmospheric observations

Atmospheric observations of greenhouse gases and associated trace species can be used in a top-down approach to quantify and attribute greenhouse gas emissions to natural and biogenic activities. In this talk we will focus on the Los Angeles megacity to explore the utility of different atmospheric observations, models, and data driven techniques to attribute and detect changes in emissions in urban regions. We will present results from a high-resolution regional model to study the impact of different emissions scenarios on the atmosphere, and assess the feasibility of atmospheric detection. We also will show diurnal in-situ observations of greenhouse gases, related trace species, and boundary layer dynamics in Los Angeles. We will explore how the combination of these observations may enable the decomposition of the observed signal into specific contributing emissions sectors.