In December 2014, two noteworthy announcements were made regarding the Orbiting Carbon Observatory -2 (OCO-2) satellite, which is operated by the NASA Jet Propulsion Laboratory (JPL). In the first announcement, at the 2014 American Geophysical Union Fall Meeting in San Francisco, California, the OCO-2 mission team showed an image of their preliminary retrieval of atmospheric CO2 concentrations, for the period October 1 – November 11, 2014. This image showed elevated CO2 concentrations over South America, southern Africa, China, and Indonesia. The likeliest cause of these elevated concentrations was biomass burning, except for China, where the likeliest cause was fossil fuel burning for energy production. The second announcement, made by the NASA Goddard Earth Sciences Data and Information Services Center (GES DISC), concerned its release of the first publicly available data from OCO-2, the Level 1 calibrated spectral radiances. The latter are in the near-infrared O2 and CO2 absorption bands, and these data are used for the retrieval of atmospheric CO2 concentrations. OCO-2 incorporates three high-resolution spectrometers that make coincident measurements of reflected sunlight in the near-infrared CO2 absorption bands near 1.61 and 2.06 μm and in the molecular O2 A-Band at 0.76 μm.
The first release of full-physics Level 2 atmospheric CO2 concentration data is expected to take place in March 2015, only a few weeks from now. The OCO-2 data will be available at the GES DISC, which also has atmospheric CO2 concentration data from the Atmospheric Infrared Sounder (AIRS). (The designation “Level 2” indicates data that are obtained along the satellite’s observational path. Global Level 3 maps of atmospheric CO2 concentration, created by binning and averaging the Level 2 data, will be available after additional data processing takes place.)
An interesting and important aspect of the OCO-2 mission is where its satellite orbits in relation to other NASA Earth observing satellites. OCO-2 was maneuvered into position to lead the “A-Train” satellite constellation, where it is being followed only a few seconds later by the Japanese Aerospace Exploration Agency (JAXA) GCOM-W1 satellite and, in sequence, by the NASA Aqua, Calipso, CloudSat, and Aura satellites. The proximity of these satellites provides multiple and nearly simultaneous observations, which allow detailed insight into processes in the Earth system that are relevant to our understanding of Earth’s atmosphere, weather, climate, and alteration of Earth’s biosphere due to human activities.
- Documentation on the currently released products can be found at
- Product pages summarizing the essential details, including data access methods, are available from
- Users can directly download data from anonymous ftp at
For More Information About OCO-2
Users are encouraged to visit the OCO-2 Project Web site at JPL, http://oco.jpl.nasa.gov/, for detailed information on the technical specifications and principles of operation of the OCO-2 spacecraft and sensor. The Web site also provides information on the physical basis of the CO2 data retrievals using the short infrared spectra acquired by the spacecraft.