City-Scale Methane Retrievals from the High-Altitude Lidar Observatory During the 2023 STAQS Campaign

The NASA Langley Research Center's High-Altitude Lidar Observatory (HALO) participated in the 2023 STAQS mission to study air quality and greenhouse gas concentrations across major metropolitan regions in the United States, such as Los Angeles, New York City, and Chicago. The spatiotemporal evolution of column and multi-layer methane, aerosol backscatter, extinction, depolarization, and mixed layer heights was observed by HALO during AM/PM single day flights and multi-day sampling of the same regions. Here, we show these measurements and assess HALO's capabilities for combined greenhouse gas and air quality measurements, novel profiling techniques for methane layer attribution, and the capability for a high-altitude lidar to provide emission estimates.