A comparison of OCO-2 XCO2 Observations to GOSAT and Models
Abstract
With their high spatial resolution and dense sampling density, observations of atmospheric carbon dioxide (CO2) from space-based sensors such as the Orbiting Carbon Observatory-2 (OCO-2) have the potential to revolutionize our understanding of carbon sources and sinks. To achieve this goal, however, requires the observations to have sub-ppm systematic errors; the large data density of OCO-2 generally reduces the importance of random errors in the retrieval of of regional scale fluxes. In this work, the Atmospheric Carbon Observations from Space (ACOS) algorithm has been applied to both OCO-2 and GOSAT observations, which overlap for the period spanning Sept 2014 to present (2+ years). Previous activities utilizing TCCON and aircraft data have shown the ACOS/GOSAT B3.5 product to be quite accurate (1-2 ppm) over both land and ocean. In this work, we apply nearly identical versions of the ACOS retrieval algorithm to both OCO-2 and GOSAT to enable comparisons during the period of overlap, and to minimize algorithm-induced differences. GOSAT/OCO-2 comparisons are used to explore potential biases in the OCO-2 data, and to better understand the nature of the bias correction required for each product. Finally, each product is compared to an ensemble of models in order to evaluate their relative consistency, a critical activity before both can be used simultaneously in carbon flux inversions with confidence.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFM.A31N..04O
- Keywords:
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- 3305 Climate change and variability;
- ATMOSPHERIC PROCESSESDE: 3337 Global climate models;
- ATMOSPHERIC PROCESSESDE: 3339 Ocean/atmosphere interactions;
- ATMOSPHERIC PROCESSESDE: 3360 Remote sensing;
- ATMOSPHERIC PROCESSES