Colette Schissel, Javier Gonzalez-Rocha, Marc Watine-Guiu: Lightning talks

Colette Schissel: Impact of the High-Emission Event Duration and Sampling Frequency on the Uncertainty in Emission Estimates

Short duration remote sensing measurements of methane emissions from oil and gas operations are being deployed at a large scale, but interpretation of these snapshot measurements is complex due to the spatial and temporal variability of methane emissions. The accuracy and precision of annual emission estimates extrapolated from short duration measurements depend on the measurement frequency and complexity of temporal emission patterns. This work examines sampling uncertainties associated with short duration measurements of varying frequencies for methane emissions from a group of sites representing the Barnett Shale region. Routine, frequent emissions are accurately captured with minimal bias through semiannual sampling; however, infrequent high-emission rate events increase the error associated with annual emission estimates, even under the assumption of no measurement uncertainty. If emission events have a duration of ≤1 week, monthly sampling has an estimated sampling error of >15%. For quarterly sampling with emission events that persist for ≤1 month, the sampling error is >30%. There is also negative bias associated with quarterly, semiannual, and annual sampling, which suggests infrequent campaigns may be systemically underestimating emissions. The sampling error increases as the duration of the high-emission events becomes shorter, making the temporal persistence of emission events an important factor in designing measurement protocols.

Bio

Colette Schissel is a chemical engineering PhD candidate and NSF graduate research fellow in Dr. David Allen's group at the University of Texas at Austin. She received her B.S. from Cornell University, also in chemical engineering. Her thesis research focuses on developing calculation frameworks and computational tools that enable the design, interpretation, and synthesis of multiscale measurements of methane emissions from oil and gas production regions. Colette has previously interned at the Gas Technology Institute and at Scientific Aviation. She is currently working as a data analyst for the Oil and Gas Methane Partnership (OGMP 2.0) at the United Nations Environment Programme.

Javier González-Rocha: Toward on-demand measurements of greenhouse gas emissions using an uncrewed aircraft Aircore system

Methane is a potent greenhouse gas responsible for a quarter of anthropogenic radiative forcing. Increases in agriculture, oil and gas, and waste management activities have contributed to the growth of atmospheric methane levels and resultant climate warming. Due to its relatively short atmospheric lifetime of 10-12 years and high global warming potential of 86 on a 20-year timeframe, methane is an important target for climate mitigation. This will require new measurement techniques to estimate emissions and verify reductions at the facility scale. This talk will discuss how small uncrewed aircraft systems and Aircore technology can help reduce the uncertainty of methane emissions estimates from both dairy farms and oil and gas operations.

Bio

Dr. Javier González-Rocha is an assistant professor in the Department of Applied Mathematics at UC Santa Cruz. Prior to joining UC Santa Cruz, Dr. González-Rocha earned both a B.S. and M.S. degree in mechanical engineering from CSU-Sacramento, and Ph.D. degree in aerospace engineering from Virginia Tech. His research leverages flight dynamic modeling, state estimation, and low-cost sensors to sense wind, turbulence, and air composition within the atmospheric boundary layer using aerial robotic systems.

Marc Watine-Guiu: Enabling current geostationary satellites to detect, locate and quantify extreme methane emission events

Decreasing atmospheric methane emissions is an urgent priority to slow near-term climate change. Satellites have unique capabilities to pinpoint methane sources in support of climate action, but the current observing system is entirely in low-Earth orbit and thus incapable of monitoring diurnal variability and intermittency of emissions. Here we demonstrate continuous 5-minute monitoring of methane point emissions with the U.S. Geostationary Operational Environmental Satellite (GOES) constellation. Our techniques can be adapted to other geostationary satellite systems for Europe, Africa, and Asia to provide continuous monitoring of large and brief methane releases.

Bio

Marc Watine-Guiu is a Computer Science MSc student from ETH Zürich, conducting his research project at Harvard's Atmospheric Chemistry group with Daniel Varon. Before joining the group, he worked for Kayrros, a French company using satellite imagery to detect methane super-emitters.