[A-CG49] Greenhouse Gas Monitoring from Space: Current Capabilities, Challenges, and Future Needs

[ACG49-04] The OCO-3 Mission: Performance of the Snapshot Area Map and Target Mode Observations and Coincident Measurements with the OMPS and TROPOMI Air Quality Sensors

*thomas p kurosu¹、Annmarie Eldering¹、Ralph basilio¹、matthew Bennett¹、Christopher O'Dell²、Peter Somkuti²、Thomas Taylor²、Matthäus Kiel¹、Robert Nelson¹、Gary Spiers¹、Brendan Fisher¹、Ryan Pavlick¹、Gregory Osterman¹、Joshua Laughner³、Graziela Keller-Rodrigues¹、Shanshan Yu¹、David Crisp¹、Paul Wennberg³ (1.NASA Jet Propulsion Laboratory/California Institute of Technology, Pasadena, CA 91109、2.Colorado State University, Fort Collins, CO 80523、3.California Institute of Technology, Pasadena, CA 91125)

キーワード：Greenhouse Gas Monitoring, Carbon Cycle, International Space Station

The Orbiting Carbon Observatory 3 (OCO-3) was launched to the International Space Station (ISS) on 4 May 2019 and was successfully installed on 10 May 2019. First Light occurred in late June 2019, and the in-orbit check out of the instrument extended through July 2019. OCO-3 records reflected sunlight in the near-Infra Red spectral region to estimate the column average CO₂ dry air mole fraction (XCO₂) and solar-induced chlorophyll fluorescence (SIF). It complements the OCO-2 mission by employing a dedicated Snapshot Area Map (SAM) mode to map spatial areas of up to 80x80 km² on the Earth’s surface, including cities, volcanoes, and photosynthetically active surface types. The inclination of the ISS orbit limits OCO-3 to observations within +/- 52º latitude, but allows measurements at all times of day between sunrise and sunset to resolve diurnal variations in XCO₂ and SIF.

CO₂ emissions and air quality are closely linked, particularly over large urban agglomerates. OCO-3’s SAMs allows, for the first time, detailed studies of the relationship between CO₂ emissions and air quality tracers over megacities. Compared to CO₂, NO₂ is short-lived and can serve as indicator for temporally and locally enhanced fossil fuel emissions, as well as longer-term trends of urban development and growth.

We present the current status of the OCO-3 mission, with focus on SAM performance to identify anthropogenic CO₂ signals, and comparisons of OCO-3 SAM and Target Mode measurements of XCO₂ with NO₂ observations from NASA’s Ozone Monitoring and Profiler Suite on Suomi/NPP and JPSS-1 and ESA’s Sentinel-5 Precursor/TROPOMI. We present details on the performance of selected OCO-3 SAM and Target Mode observations, identify temporally and spatially near-coincident OMPS and TROPOMI measurements, and derive correlation statistics between CO₂ and the air quality tracers, with the aim to establish coincidence data record over the OCO-3 life time.