Greenhouse Gas Emissions

Project Title: Methane and Carbon Dioxide Point Source Emissions Validaion and Analysis

EMIT has shown initial capability for quantifying methane (CH4) and CO2 point source emissions. These capabilities have drawn strong public and scientific interest for a variety of carbon cycle research projects and applications. Key to adoption of these greenhouse gas products is robust and transparent validation of L2-L4 products, including retrieval concentration maps, individual plume images, emissions quantification, uncertainty estimates, and facility and sector attribution for point sources. For this project, we propose three main objectives. The first objective will be to execute a CH4 and CO2 point source emission validation program to quantify minimum detection limits and precision and bias of emission estimates derived from EMIT observations. The second objective will be to independently process all cloud-free EMIT observations over priority regions to detect and quantify emissions from CH4 point sources, attribute them to key emission sectors, and integrate the resulting dataset with airborne point source data from AVIRIS-NG, GAO, and the upcoming Carbon Mapper satellites into Carbon Mapper's

Global Waste Sector Baseline, a core project under the Global Methane Pledge's Waste Pathway. The final objective will be to extend the impact of EMIT observations by infusing L2-L4 CH4 and CO2 products into Carbon Mapper's global open data platform and ongoing stakeholder engagement programs.

Successful validation of quantitative CH4/CO2 products means independent evaluation of retrieval concentration maps, CH4/CO2 plume detection and delineation, emission quantification and uncertainty estimates, and sectoral attribution. We propose a comprehensive validation program which will include controlled release experiments, simultaneous under flights with aircraft, and intercomparisons with emission estimates from other satellites and surface measurements. Most of the component systems and protocols are already funded and planned as part of the validation efforts for the Carbon Mapper mission which we propose to extend to include EMIT. This validation framework includes established Carbon Mapper collaborations with the US Environmental Protection Agency, the California Air Resources Board, University of California Berkeley, Stanford University, and Colorado State University. As we validate each product, we will share algorithms, benchmark data sets, and findings with the EMIT Science Data System team. With robust CH4 and CO2 products, we propose to use these data to analyze the global distribution of point sources. We plan to focus our CH4 analysis on the global waste sector, a historically understudied source of methane and an area where Carbon Mapper has strong partnerships and expertise. We also plan to apply our Observing System Completeness metric which combines detection limits, spatial coverage and sample frequency to generate completeness heat maps for EMIT observations of emitting regions. This will help provide context for the observations, including objective, quantitative assessments of EMIT's observing system coverage and completeness of anthropogenic emissions including variable and intermittent sources. This proposal will directly address the solicitation by providing validation of an EMIT product of high interest. Additionally, this proposal will support the NASA science objectives to understand global carbon cycle and further the use of Earth system science research to inform decisions and provide benefits to society.

Project Team

Alana Ayasse

Carbon Mapper, Inc.