Earth below us, greening, glowing, cycling carbon, photosynthesis!
Red fluorescence tells the story, satellites can measure, measure it!
Wait, those aren’t the lyrics to Major Tom Coming Home. Not quite, but more appropriate for the upcoming OCO-2 NASA mission scheduled to launch in less than 24 hours! That stands for Orbiting Carbon Observatory-2, a satellite equipped with instruments to measure carbon dioxide in the Earth’s atmosphere. What does photosynthesis have to do with it? A lot. No matter how the carbon dioxide finds its way into the atmosphere- vehicle emissions, thawing tundra, the panting of my dogs in the Louisiana summer heat- photosynthetic organisms are its ticket out of the atmosphere and back into the solid state. The OCO-2 satellite will be collecting spectral data for direct measurements of atmospheric carbon dioxide as well as sun-induced fluorescence to monitor photosynthesis on a global scale.
Watching in a trance, the crew is certain, Nothing left to chance, all is working…
Now that you know what the OCO stands for, you might be wondering about the 2. Of course there was a ‘1’. Starting with 2 would just drive people like the scientists and engineers at NASA crazy. The OCO-1 launched in 2009 with a similar mission to collect carbon dioxide concentration data, but it failed to launch properly and crashed into the ocean before making it anywhere close to its orbit. Sigh. After I’m sure a lot of this happened, the scientists and engineers got back to work to make the replacement mission even better. You can bet that everything has been quadruple checked this time.*
Starting to collect requested data, What will it effect when all is done?
Remember when I told you how nifty it was that satellites were measuring photosynthesis from space while I was making the same measurements in the lab? Well, it’s not just a scientific novelty being measured because it can be. Chlorophyll fluorescence on a global scale provides critical information for accurate models of primary productivity and global carbon cycles. A recent report in PNAS showed that sun-induced fluorescence data could be used to model gross primary productivity.** The authors found that estimates based on chlorophyll fluorescence data were much higher for major agricultural areas like the U.S. Corn Belt than models using other measures. These findings mean our current models may be underestimating how much modern agriculture and other managed areas contribute to the Earth’s carbon cycle. That report focuses on land photosynthesis, but I hope that the satellites will be collecting the chlorophyll fluorescence signal from both the land and the oceans. Let’s not forget that the photosynthetic bacteria in the ocean account for about half of the Earth’s primary productivity. I’m sure they have it covered since they have long been interested in mapping ocean color.
Check out this video for more on the OCO-2 mission.
There’s a lot of politics behind the amounts of carbon dioxide in the atmosphere, what’s causing them to creep increasingly higher and what that means for global climate patterns. Collecting accurate data on how much carbon dioxide is released into the atmosphere as well as the capacity of photosynthetic organisms to reclaim that carbon dioxide will greatly aid in global climate models that will be used to direct policy.
OCO-2 Satellite, Oh how I wonder what you will see for us. Safe journey and Godspeed.
UPDATE 07/01/14: For those of you that didn’t set your alarms early to watch the launch…
The computer has the evidence, need to abort, the countdown stops…
At T-46 seconds to be precise. There was a problem with the pad’s water system during the launch sequence that caused the mission to be aborted today. The satellite and rocket are all still ready to go, but NASA’s scientists and engineers need to figure out the source of the problem and a new launch date for the OCO-2 mission. Check here for the latest. And follow OCO-2 on Twitter!
The OCO-2 do-over launch was successful today. Don’t just take my word for it, listen to OCO-2:
*If a launch failure happens again, I’m willing to start entertaining conspiracy theories.
**It should be noted that chlorophyll fluorescence has long been a standard technique in the laboratory for analyzing photosynthetic efficiency. Scientists have even scaled it up for field analysis. The real breakthrough in recent years has been observing this faint signal from plants via satellite using only the incident natural sunlight (not artificially bright light subjected to plants in a very controlled way).
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