PULLMAN – George Mount, professor in the WSU Department of Civil and Environmental Engineering’s Laboratory for Atmospheric Research, has been heavily involved in developing the NASA Jet Propulsion Laboratory Orbiting Carbon Observatory satellite, set to launch from California’s Vandenberg Air Force Base early tomorrow morning.
The satellite is expected to measure precise carbon dioxide levels in the earth’s atmosphere from space for the first time and provide valuable information to help in understanding the effects of carbon dioxide (CO2) on global warming.
Rapidly increasing levels of carbon dioxide, the greenhouse gas most abundantly produced by human activities, are suspected by many scientists to be contributing to climate change. Levels of CO2 have risen significantly in the past 200 years due to fossil fuel combustion and other human activities to levels significantly higher than observed over the past 650,000 years. Surprisingly, however, only a handful of places in the world make precise and continuous carbon dioxide measurements.
Carbon dioxide levels in 2007 varied worldwide from about 372 to 384 parts per million, with higher levels found in the Northern Hemisphere where most CO2 sources are located. Only about half of the carbon dioxide that is emitted ends up in the atmosphere. The rest ‘sinks,’ or is absorbed back into the biosphere and hydrosphere. But generalized information doesn’t provide a clear picture on what the specific regions are where the sinks are located. Such information is important for setting policies, for instance, on what areas of the ocean or forests might be most valuable to protect to combat the implications of climate change.
Mount said the carbon observatory satellite will use high-resolution, diffraction grating spectrometers to measure carbon dioxide from space to an accuracy of one part per million, or 1/3 of one percent. The instruments will make the measurements in small footprints of two kilometers on a side. The satellite will fly around the world every ninety minutes, so that every month researchers will be able to get a detailed and precise picture of carbon dioxide emissions around the globe.
Being able to take precise measurements from space is challenging, said Mount, because the instrumentation has to be able to take into account varying topography that impacts carbon dioxide levels below the satellite, and making measurements from space where you cannot recalibrate or work on the instrument to a precision of 0.3% is a very difficult job. The machinery also has to be able to withstand taking measurements in a vacuum and the extreme cold of space. Once the satellite launches, any needed instrument repairs would be virtually impossible.
For more information visit: http://www.nasa.gov/mission_pages/oco/main/index.html
