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GESTAR II Seminar Series, Thursday, July 14th at 11:00am

Join us for a virtual seminar by Dr. Xiong Liu from the Smithsonian Astrophysical Observatory, part of the Center for Astrophysics / Harvard and Smithsonian. His talk is titled "Two Satellite Missions to Launch in 2023: TEMPO and MethaneSAT." Dr. Liu will present an overview of TEMPO and MethaneSAT, on which he splits his efforts.

Date and Time: Thursday, July 14, 2022 at 11:00am
Join us via Teams. 

TEMPO, NASA's first EVI and first host payload, will measure atmospheric pollution over North America from Mexico City to the Canadian oil sands, and from the Atlantic to the Pacific, at high spatiotemporal resolution from the geostationary (GEO) orbit. TEMPO uses UV/visible spectroscopy to measure O3 profiles, including lower tropospheric O3, and columns of NO2, H2CO, SO2, C2H2O2, H2O, BrO, IO, as well as clouds aerosols, and UVB. TEMPO provides a tropospheric measurement suite that includes the key elements of tropospheric air pollution chemistry and captures the inherent high variability in the diurnal cycle of emissions and chemistry. Built by Ball Aerospace in Nov. 2018, the TEMPO instrument was just completely integrated into the host Intelsat 40e at Maxar and scheduled for launch into the GEO at 91W in Jan 2023 via a SpaceX Falcon 9. The science team finished the operational-ready V3 science algorithm software. The Operation/Mission Readiness Review will occur in Oct. 2022. Nominal operation is expected to begin in Aug. 2023 after the commissioning phase. Science data products will be archived and distributed at NASA's ASDC and released to the public in Feb. 2024. TEMPO will be part of a geostationary constellation to measure air quality along with GEMS over Asia (launched in Feb. 2020) and Sentinel-4 over Europe (to launch in 2023).

The MethaneSAT mission is commissioned by MethaneSAT LLC (a subsidiary of the Environmental Defense Fund) to map and quantify CH4 emissions over 80% of global oil and gas fields and other agriculture and urban sources, and to produce actionable data to reduce oil and gas CH4 emission by 45% by the end of 2025. The mission aims to fill the critical data gap between the global mapping satellites (low spatial resolution, moderately high precision), and the growing number of point-source missions (high spatial resolution, but small field of view and low precision). The MethaneSAT instrument consists of two push-broom imaging spectrometers: the CH4 spectrometer to detect CH4 and CO2 absorption and the O2 spectrometer to detect O2 absorption. MethaneSAT's target observations will consist of a wide-observing swath, a high spatial resolution, and a low detection threshold, which will enable quantification of both point and diffuse sources. Over the past year, substantial progress has been made in assembly, integration, and testing of MethaneSAT's two imaging spectrometers built by Ball Aerospace. Integration with the platform bus supplied by Blue Canyon Technologies will commence in Q3 2022 followed by flight-system level characterization and calibration activities. MethaneSAT is scheduled for launch in Q2-3 2023, also aboard a SpaceX Falcon 9 launch vehicle. MethaneAIR, an airborne precursor instrument, was built in 2019 and successfully deployed in July/Aug. 2021 aboard the NSF/NCAR Gulfstream V; this produced ~50 hours of observations. These measurements have been used to develop and challenge the trace gas retrievals and flux algorithms needed to complete the MethaneSAT mission. Future MethaneAIR flights are planned to map additional US CH4 emissions to complement MethaneSAT measurements (~60 hours/month) and participate in MethaneSAT validation activities.

Dr. Liu is currently a physicist at Smithsonian Astrophysical Observatory (SAO), Center for Astrophysics (CfA) | Harvard & Smithsonian. He is the Deputy PI for the TEMPO (Tropospheric Emissions: Monitoring of Pollution) mission, and the SAO lead of the MethaneSAT mission working on raw to L3 algorithms. He specializes in remote sensing of atmospheric trace gases, especially ozone profile including tropospheric ozone, aerosols, clouds from satellite, airborne and ground-based instruments, L0-1b processing and instrument calibration, and the development of satellite instrumentation. He obtained his BS in Environmental Science from Nankai University, MS in Atmospheric Chemistry from Chinese Academy of Science, and MS in Computer Science and PhD in Atmospheric Science from University of Alabama in Huntsville. He had one year of postdoc at SAO and then became a physicist there until May 2007. He then joined in GEST/UMBC as an assistant and associate research scientist until January 2010 when he returned to work at SAO.

For more information on the GESTAR II Seminar Series, click here.

Posted: July 7, 2022, 4:51 PM