2:15 PM - 2:30 PM
[AAS01-03] Measuring Atmospheric Carbon Dioxide with the NASA Orbiting Carbon Observatory-2 (OCO-2)
Keywords:carbon dioxide, carbon cycle, remote sensing
Preliminary, global maps of XCO2 compiled from soundings collected over 16-day ground track repeat cycles reveal some of the most robust features of the annual atmospheric carbon cycle. Regions of enhanced XCO2 that are co-located with intense fossil fuel emission sources in the eastern US and eastern China were most obvious in the fall and early winter of 2014, when the north-south gradient in XCO2 was small. XCO2 enhancements coincident with intense biomass burning in the Amazon, central Africa, and the Indonesian Archipelago were also most obvious during this season. In the early spring, when the pole-to-pole gradients in XCO2 are largest, contributions from these emission sources were clearly seen in individual orbit tracks but were much less obvious in the global maps. However, between late May and early July of 2015, OCO-2 maps show a 2-3% reduction in XCO2 across much of the northern hemisphere, as the land biosphere rapidly absorbs CO2 through photosynthesis. As the carbon cycle science community continues to analyze these OCO-2 data, quantitative estimates of regional-scale emission sources and natural sinks (absorbers) are expected to emerge.
The OCO-2 team started delivering Version 7 products to the Goddard Earth Sciences Data and Information Services Center (GES-DISC) in early June 2015. These products include calibrated, spectral radiances (Level 1 products), and retrieved geophysical quantities, including spatially resolved estimates of XCO2, surface pressure, and solar-induced chlorophyll fluorescence (Level 2 products). The calibration of the Level 1 products continues to be refined, and the effort to cross calibrate these products with those from the Japanese Greenhouse gases Observing SATellite (GOSAT) are under way. The Level 2 products are currently being validated against observations from the Total Carbon Column Observing Network (TCCON) and other standards to identify and correct biases. This presentation will summarize these and other aspects of the OCO-2 mission status, early products, and near-term plans.