Phase 2 of Orbiting Carbon Observatory Field Campaign Begins

 
Published: 31 August 2008
A camera, weather station, and sun tracker with a protective dome are located on the roof of the fully automated FTS mobile laboratory. Inside the shelter, the spectrometer receives the reflected solar beam from the sun tracker, while the main computer system operates all the instruments and acquires the data.
A camera, weather station, and sun tracker with a protective dome are located on the roof of the fully automated FTS mobile laboratory. Inside the shelter, the spectrometer receives the reflected solar beam from the sun tracker, while the main computer system operates all the instruments and acquires the data.

The Orbiting Carbon Observatory, or OCO, is a National Aeronautics and Space Administration (NASA) Earth System Science Pathfinder (ESSP) mission designed to make precise, time-dependent global measurements of atmospheric carbon dioxide from an Earth-orbiting satellite. Starting in July and lasting through 2010, the ARM Southern Great Plains (SGP) site is hosting the mobile laboratory for the OCO science team’s ground-based solar-viewing Fourier transform spectrometer (FTS). The FTS measures the near-infrared region of the solar spectrum at very high resolution, allowing scientists to calculate the concentration of greenhouse gases in the atmosphere. This campaign is the next phase of the ongoing OCO field campaign that began in 2006 at the ARM site in Darwin, Australia. Measurements from the FTS at both sites will continue through the end of the OCO mission in 2010, helping the OCO science team to validate carbon dioxide measurements obtained via satellite.

After 1 year of side-by-side tests at NASA’s Jet Propulsion Laboratory with the OCO flight instrument and the FTS, installation of the FTS mobile laboratory at the SGP site began this summer. In preparation for the satellite validation field campaign, operations staff installed a concrete pad for the laboratory and completed hookups for the equipment, data, and communication links. The OCO science team arrived in July to set up the instrumentation and peripherals. For the next several months, the science team will measure carbon dioxide and related gases, including methane and carbon monoxide, in preparation for the OCO satellite launch in January 2009. After the launch, scientists will analyze measurements from the spectrometers onboard the OCO satellite against the FTS data to improve our understanding of the natural processes and human activities that regulate the abundance and distribution of this important greenhouse gas.

The OCO science team is leveraging the ARM’s expertise and infrastructure in ground-based and in-situ sampling of atmospheric aerosol properties and carbon cycle trace gases to aid in this high-profile ESSP mission. Knowledge gained from this campaign will enable more reliable forecasts of future changes in the abundance and distribution of carbon dioxide in the atmosphere, and the effect that these changes may have on the Earth’s climate. This collaboration between DOE and NASA represents a significant contribution to the interagency Carbon Cycle Science Initiative of the U.S. Global Change Research Program.