First retrievals of XCO2 and SIF from the Orbiting Carbon Observatory-3
Abstract
The Orbiting Carbon Observatory-3 (OCO-3) was launched on May 4, 2019 and installed on the International Space Station (ISS) on May 10, 2019. Like the successful OCO-2 mission, OCO-3 collects the measurements needed to estimate the column mean carbon dioxide concentration (XCO2) and solar-induced fluorescence (SIF), both of which are used to study carbon cycle processes. However, OCO-3 differs from OCO-2 in two ways that open new possibilities. First, OCO-3 is in a low-inclination orbit that samples the dayside hemisphere, facilitating studies of diurnally varying carbon cycle processes. Second, OCO-3 includes a fast, 2-axis pointing mechanism that enables Snapshot Area Maps (SAMs), ~80x80 km images that can support studies of city-scale sources of CO2.
Here, we present first results of OCO-3 level-1 spectra, cloud screening, and retrievals of both XCO2 and SIF from OCO-3. We also describe early efforts to validate the OCO-3 calibration status and retrieved products. The ability to screen out cloudy scenes is of particular importance because high-quality XCO2 retrievals cannot be obtained in the presence of thick clouds or aerosol layers. For XCO2 retrievals, validation sources include comparisons to TCCON, analyses of variability in small, spatially-homogeneous areas, comparisons to predictions from near-real-time models, and direct comparisons to XCO2 estimates from OCO-2. SIF estimates are validated through comparisons with maps of gross primary production and where possible, SIF estimates from OCO-2. Finally, we discuss potential uses of OCO-3 data, alone and in conjunction with simultaneous observations from other space-based sensors, to yield greater insights into carbon cycle science.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.A51E..08O
- Keywords:
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- 3322 Land/atmosphere interactions;
- ATMOSPHERIC PROCESSES;
- 0412 Biogeochemical kinetics and reaction modeling;
- BIOGEOSCIENCES;
- 0428 Carbon cycling;
- BIOGEOSCIENCES;
- 0480 Remote sensing;
- BIOGEOSCIENCES