Emissions and trends from the Marcellus and Denver/Juelsberg oil and gas fields

The Marcellus and Denver/Juelsberg fields, among the most productive sources of oil and gas in the US, have been frequent targets for measurement campaigns.  Here we describe use of mobile platforms (surface and aircraft), remote sensing (lidar), and numerical simulation to quantify the emissions from these fields.  Fossil sources are often co-located with other sources such as concentrated animal feeding operations (CAFOs), wetlands, abandoned coal mines, and landfills.  To isolate the emissions from oil and gas, we employ tracers including ethane (C2H6), methane 13C isotopes, and acetic acid, H3CCOOH.  The use of surface-based mobile lidar greatly enhances measurement uncertainty for corrections due to convergence over the domain.  Improvements in engineering have greatly reduced emissions intensity over the past 10 years.