Earthsky FC_AquaTerra, Interviews
Mous Chahine: ‘No area on Earth immune from effects of greenhouse gases’
09-14-2009 - Earth
Mous Chahine, senior research scientist at NASA’s Jet Propulsion Laboratory in California, is talking about research using an instrument called the Atmospheric Infrared Sounder – AIRS – that works aboard NASA’s Aqua satellite. AIRS tracks carbon dioxide, a greenhouse gas known to cause global warming.
Mous Chahine: From AIRS, we have made one discovery. It is that carbon dioxide is not well mixed. It is lumpy. We can look at the carbon dioxide emitted from Asia moving across the Pacific to North America, where we add more carbon dioxide, and then to Europe. It goes round and around.
Chahine said AIRS also tracks water vapor in the atmosphere, which he called the planet’s most potent greenhouse gas. He said warming global temperatures mean more evaporation from the oceans. This water vapor gets stored in Earth’s upper atmosphere, heating up the Earth even more.
Mous Chahine: If the carbon dioxide is causing global warming of, say, one degree, the resulting water vapor in the atmosphere will multiply it so that the net is two and a half degrees, not just one.
Chahine explained that AIRS tracks carbon dioxide using spectra, or colors.
Mous Chahine: We make the measurement in the infrared. This is the region in which we get heat emitted from the atmosphere. If we have more carbon dioxide, we have more energy emitted, and the satellite will measure more energy. What we do is take those measurements which we call spectra [infrared colors], and we unscramble it to see how much change from carbon dioxide, clouds, or water vapor.
Chahine said carbon dioxide is the most demanding gas to study.
Mous Chahine: Because we are asked to measure it one part per million. With AIRS we have shown we can do it between one and two. We have to be very careful, very attentive – this is a message to my colleagues. Treat your instrument with infinite care, it will pay off.
Chahine said AIRS has produced six years worth of global carbon dioxide data – the longest-running measurement. He said that a future project for AIRS is identifying Earth’s natural carbon dioxide ‘sinks’ – that is, CO2 storage spots like oceans and forests that might help keep Earth cool.
Our thanks today to NASA’s Aqua Mission, improving our knowledge of our home planet through satellite observations.
Written by Beth Lebwohl
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Moustafa Chahine
Moustafa ‘Mous’ Chahine studies the effects of increased carbon dioxide on the Earth’s hydrological cycle, and the comparative climatology of Mars, Venus, and Earth. He is chief scientist of the Jet Propulsion Laboratory in California. Dr. Chahine has served as a member of the NASA Earth System Sciences Committee and is currently chairman ... >>
There is an interesting parallel study conducted by the Japanese, called GOSA or The Greenhouse gases Observing SATellite. Their data seem to collaborate the AIRS study regarding the less than uniform mixing of CO2 but offers an interesting graphic depiction of GHG distribution over landmass. Here’s the link:
http://www.gosat.nies.go.jp/eng/GOSAT_pamphlet_en.pdf
What I find most interesting is China is outputting significantly more green house gasses as compared to the US (see the distribution graphs on page 8). If you count the red dots (CO2 hot spots), China has 15 red zones as compared to the US which has only three. Also interesting is the GHG hot spot over the Grise Fiord in the Arctic. Anyone have a thought on why it is there?
I’m curious about the effects of ghg with the complexity of NOx as with mixing with the water vapor that Mous lists.
On hot days, we have more, yet the cycle is “slightly” reversed on cold, cloudy days. A mystery.
A atmospheric gas more common than CO2 and also more potent as a greenhouse gas than CO2 is WATER VAPOR. Hardly anyone mentions that and weathermen call it humidity.
http://climatedepot.com/a/3689/Australian-PM-Rudd-warns-skeptics-are-too-dangerous-to-ignore-and-are-holding-the-world-to-ransom–Climate-Depot-Responds