February 19, 2009 4 mb MP3
Narrator: The space hunt is on--for carbon dioxide.
I'm jane platt with NASA's Jet Propulsion Laboratory in Pasadena, California. Carbon dioxide---a very high-profile chemical right now. Scientists say it's a major contributor to global warming. The Orbiting Carbon Observatory is NASA's first spacecraft dedicated to studying carbon dioxide in Earth's atmosphere--from space.
Basilio: Well, we stand on the doorstep of a historical moment. The data from the Orbiting Carbon Observatory are going to be able to allow scientists to be able to produce more accurate models of the global carbon cycle. And the models will actually be able to produce results that policymakers here in the United States and throughout the world will be able to use in order to make better-informed decisions on how best to control and even manage carbon dioxide emissions in the future.
Narrator: Ralph Basilio of JPL, deputy project manager for the Orbiting Carbon Observatory. Right now, carbon dioxide monitoring is limited, but this new mission will change all that.
Basilio: We'll collect on the order of about 37,000 measurements every orbit. Now there's 14-1/2 orbits per day, and there's a 16-day repeat cycle. So if you add everything up, we are looking to collect on the order of about eight million pieces of data over a little more than a two-week long period. And we'll do that repeatedly.
Narrator: Scientists want to know more about carbon dioxide sources--where it comes from, and carbon dioxide sinks--where it is stored. Natural sources include volcanoes, brush fires, respiration of plants and animals. The human sources? Here's David Crisp of JPL, principal investigator for the Orbiting Carbon Observatory.
Crisp: About 85 percent of all of the carbon dioxide that humans emit to the atmosphere comes from the burning of things like coal, natural gas, fuel oil, gasoline. The rest comes from such things as land use practices, for example we might burn our crops at the end of a growing season, for example, and that releases carbon dioxide. Other things that release carbon dioxide that we do include things like manufacturing cement, which actually releases a lot of carbon dioxide into the atmosphere. A lot of other manufacturing processes do as well.
Narrator: The carbon dioxide sinks--where it is pulled out of the atmosphere and stored--are the ocean and plants on land. But there is a mystery about the sinks.
Crisp: More than half of the carbon dioxide that we have been putting into our atmosphere since the beginning of the industrial era has been disappearing someplace. Most of that, we think, is being absorbed either by the oceans or by plants on land. And this is something that is fairly well understood, but we don't know where the plants are absorbing carbon dioxide, we don't know what the relative fraction of carbon dioxide being absorbed by the ocean is, versus what's being absorbed on land.
Narrator: Crisp and his colleagues will use the new observatory to learn where the missing carbon dioxide is going, and why the levels fluctuate so wildly.
Crisp: From year to year, the amount of carbon dioxide that's absorbed by the Earth's oceans and land plants varies dramatically. Some years the Earth absorbs almost a hundred percent of the carbon dioxide that humans release. Other years, the Earth absorbs almost none. We don't know why.
Narrator: By helping scientists solve mysteries like that, and policymakers plan for the future, the Orbiting Carbon Observatory, plus satellites like the recently-launched Japanese Gosat, and the Airs instrument on NASA's Aqua spacecraft, may ultimately benefit those of us who reside here on Planet Earth. More info on the Orbiting Carbon Observatory is at www.nasa.gov/oco . Thanks for joining us for a podcast from NASA'a Jet Propulsion Laboratory.