Get started
Work

Reply on RC2

Year: 2022
Type: peer-review
Abstract: . We use satellite methane observations from the Tropospheric Monitoring Instrument (TROPOMI), for May 2018 to February 2020, to quantify methane emissions from individual oil and natural gas ( O/G ) basins in the US and Canada using a high-resolution (∼25 km) atmospheric inverse analysis. Our satellite-derived emission estimates show good consistency with in situ field measurements (R=0.96) in 14 O/G basins distributed across the US and Canada. Aggregating our results to the national scale, we obtain O/G -related methane emission estimates of 12.6±2.1 Tg a−1 for the US and 2.2±0.6 Tg a−1 for Canada, 80 % and 40 %, respectively, higher than the national inventories reported to the United Nations. About 70 % of the discrepancy in the US Environmental Protection Agency (EPA) inventory can be attributed to five O/G basins, the Permian, Haynesville, Anadarko, Eagle Ford, and Barnett basins, which in total account for 40 % of US emissions. We show more generally that our TROPOMI inversion framework can quantify methane emissions exceeding 0.2–0.5 Tg a−1 from individual O/G basins, thus providing an effective tool for monitoring methane emissions from large O/G basins globally.
DOI: 10.5194/acp-2022-155-ac2
Author: Lu Shen
Language: English
Open Access status: gold
Award: WE PROPOSE TO CONTINUE OUR WORK ON THE NASA CMS SCIENCE TEAM TO IMPROVE KNOWLEDGE OF METHANE EMISSIONS IN NORTH AMERICA AND GLOBALLY THROUGH THE EXPLOITATION OF SATELLITE DATA AND IN SERVICE TO STAKEHOLDERS. THERE IS CONSIDERABLE NEED TO ASSESS GAPS IN NATIONAL METHANE EMISSION INVENTORIES INCLUDING CONTRIBUTIONS FROM DIFFERENT SECTORS. THE RESUMED GROWTH IN GLOBAL ATMOSPHERIC METHANE OVER THE PAST DECADE HAS ATTRACTED MUCH ATTENTION BUT ITS CAUSE IS STILL BEING DEBATED. OUR WORK WILL ADVANCE UNDERSTANDING BY BRIDGING THE GAP BETWEEN TOP-DOWN INFORMATION FROM ATMOSPHERIC METHANE OBSERVATIONS (SATELLITE AND SUBORBITAL) AND BOTTOM-UP INFORMATION FROM PROCESS-BASED INVENTORIES. WE WILL USE STATE-OF-SCIENCE POLICY-RELEVANT NATIONAL EMISSION INVENTORIES INCLUDING ERROR ESTIMATES TO SERVE AS PRIOR INFORMATION IN INVERSIONS OF SATELLITE DATA FROM GOSAT (2009-PRESENT) AND TROPOMI (2017 LAUNCH). FROM THERE WE WILL BE ABLE TO EVALUATE THESE INVENTORIES AND PROVIDE GUIDANCE FOR IMPROVEMENTS. THE LONG HIGH-QUALITY RECORD FROM GOSAT WILL PROVIDE STRONG CONSTRAINTS ON REGIONAL SOURCES AND UNIQUE INSIGHT INTO THE FACTORS DRIVING THE METHANE TREND. TROPOMI WITH ITS GLOBAL DAILY COVERAGE IS EXPECTED TO CONSIDERABLY INCREASE OUR ABILITY TO QUANTIFY METHANE EMISSIONS FROM SPACE INCLUDING SEASONAL VARIATIONS. OUR WORK WILL BUILD ON A STRONG COLLABORATION WITH EPA ALREADY DEVELOPED THROUGH CMS. THIS COLLABORATION HAS PRODUCED A SPATIALLY RESOLVED VERSION OF THE NATIONAL GREENHOUSE GAS INVENTORY (GHGI) INCLUDING SCALE-DEPENDENT ERROR ESTIMATES. WE WILL APPLY THIS INVENTORY AS PRIOR ESTIMATE FOR INVERSIONS OF SATELLITE DATA AND WORK WITH EPA IN THE INTERPRETATION OF RESULTS TO EVALUATE AND IMPROVE THE GHGI. WE HAVE ALSO DEVELOPED AN ENSEMBLE-BASED GLOBAL WETLAND EMISSION INVENTORY (WETCHARTS) THAT WE WILL USE IN OUR INVERSIONS TO NARROW UNCERTAINTY IN BIOGEOCHEMICAL PROCESS CONTROLS. WE WILL DEVELOP NEW COLLABORATIONS WITH ENVIRONMENT AND CLIMATE CHANGE CANADA (ECCC) AND THE MEXICAN INSTITUTO NACIONAL DE ECOLOG A Y CAMBIO CLIM TICO (INECC) TO PRODUCE SPATIALLY RESOLVED VERSIONS OF THEIR NATIONAL INVENTORIES ENABLING EVALUATION OF THESE INVENTORIES WITH SATELLITE DATA THROUGH OUR INVERSION FRAMEWORK. WE WILL APPLY INNOVATIVE INVERSE METHODS TO ACHIEVE HIGH-RESOLUTION CONSTRAINTS ON METHANE EMISSIONS AND TRENDS FOR NORTH AMERICA AND GLOBALLY WITH FULL ERROR CHARACTERIZATION. SUBORBITAL DATA (NOAA TCCON SITES; ATOM SONGNEX CARVE SEAC4RS ACT-AMERICA AIRCRAFT CAMPAIGNS) WILL BE USED AT ALL STAGES OF THE ANALYSIS. SPECIFIC TASKS FOR THE PROJECT WILL INVOLVE: (1) INTERPRET THE GOSAT SATELLITE RECORD (2009-PRESENT) USING ADVANCED INVERSE METHODS AND TOGETHER WITH SUBORBITAL DATA TO CONSTRAIN METHANE EMISSIONS AND THEIR TRENDS WITH FULL ERROR CHARACTERIZATION GLOBALLY AND FOR NORTH AMERICA AT HIGH RESOLUTION; (2) APPLY INVERSION RESULTS TO EVALUATE NATIONAL METHANE INVENTORIES FOR THE US CANADA AND MEXICO WORKING IN COLLABORATION WITH EPA ECCC AND INECC; (3) NARROW UNCERTAINTIES IN WETLAND EMISSIONS AND THE UNDERLYING PROCESS CONTROLS BY APPLYING INVERSION ERROR REDUCTIONS TO A LARGE ENSEMBLE OF BOTTOM-UP INVENTORIES; (4) START INTERPRETING TROPOMI OBSERVATIONS AS SOON AS THEY BECOME AVAILABLE (EXPECTED MID-2018) TO IMPROVE TOP-DOWN CONSTRAINTS ON METHANE EMISSIONS INCLUDING SEASONAL INFORMATION. PI DANIEL JACOB AND CO-I ANTHONY BLOOM WILL SERVE ON THE CMS SCIENCE TEAM AND WILL BE ENGAGED IN SPECIFIC COLLABORATIVE AND SERVICE ACTIVITIES AS PART OF THE TEAM. JACOB WILL CONTINUE TO LEAD THE CMS METHANE WORKING GROUP.
OpenAlex ID: W4281481391
Cites: 47
Cited by:
Related to: 10