The observatory will carry a single instrument consisting of three high-resolution grating spectrometers. "We will probably be able to see more local features" in the 2 to 10 kilometer swath of the Earth covered in each pass, Frankenberg said in an interview. OCO-2 will be stationed in a 705-kilometer (438 mile)-high polar orbit as part of an international constellation of remote sensing satellites.
While working with Japanese partners, Frankenberg also was able to test retrieval algorithms that will be used to gather and process data collected by the OCO-2 spectrometers. This testing turned out to lessen the blow of losing OCO.
"We have the luxury of knowing what to expect," Frankenberg noted, whereas a mission flown in 2009 would have faced far greater uncertainty in dealing with CO2 data. He estimates that OCO-2 will gather about 10 gigabytes of science data per day.
Without Frankenberg's work, the peculiarities of the observing solar-induced fluorescence would be little more than an "error source" for the OCO-2 spectrometers. Instead, Basilio added, "We were able to make lemonade out of lemons."
Roughly half of man-made CO2 emissions remain in the atmosphere. The other half is dissolved in the ocean or taken up by Earth's biosphere where it is stored in carbon sinks that are effectively shielding humanity from the full climatic effect of our emissions.
One of the goals of the OCO mission is to determine how long we can count on the biosphere "doing us a favor," Frankenberg explained. "Will this sink persist in the future or will it become neutral or even reverse?" he asked.
See an animation of the OCO-2 mission here.
— George Leopold is a science writer based in Washington, D.C. He also was the executive editor at EE Times for nearly 20 years.