Category: Assessing Air Quality and Water Resources
Project Team: San Francisco Bay Area Health & Air Quality
Team Location: NASA Ames Research Center ÛÒ Moffett Field, California
AJAX flight path over the San Francisco Bay Area with points indicating methane concentrations from low (green) to very high (red). Image Credit: San Francisco Bay Area Health & Air Quality team
Authors:
Maya Midzik
Joseph Abbate
Garima Raheja
Mentors/Advisors:
Dr. Abhinav Guha (Bay Area Air Quality Management District)
Dr. Laura Iraci (Ames Research Center)
Dr. Josette Marrero (NASA Postdoctoral Program)
Warren Gore (Ames Research Center)
Dr. Emma Yates (Bay Area Environmental Research Institute)
Dr. Juan Torres-PÌ©rez (Bay Area Environmental Research Institute)
Past/Other Contributors:
Chippie Kislik (Center Lead)
Abstract:
Methane, or CH4, is the second-most important anthropogenic greenhouse gas in terms of radiative forcing, with emissions coming from a variety of human-induced sources in populated areas, such as livestock, landfill, and wastewater. The Bay Area Air Quality Management District (BAAQMD) uses traditional bottom-up methodologies to produce source-specific emissions estimates for their regional greenhouse gas inventory; however, recent literature demonstrates that bottom-up methodologies are underestimating CH4 emissions by up to 50 percent in many regions of California, including the San Francisco Bay Area. This discrepancy is investigated in this project by comparing ground-based in situ greenhouse gas measurements with sub-Planetary Boundary Layer aircraft measurements from the NASA Alpha Jet Atmospheric eXperiment (AJAX). Understanding the spatial and temporal variations in CH4 can help identify hotspots and trace the sources of high-CH4 plumes. Integrating these findings into their traditional bottom-up methodologies has offered a more accurate approach to compiling this inventory. Furthermore, the identification of possible high-emission point sources may suggest areas of future in situ measurement for the agency’s Mobile Greenhouse Gas Measurement Network, or remotely sensed total column measurements by targeted greenhouse gas satellites such as Greenhouse Gases Observing Satellite (GOSAT).