2009 The NASA Orbiting Carbon Observatory Measuring Carbon Dioxide from Space

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Making Precise XCO2 Measurements from Space
• CO2 and other gases absorb only certain colors of light,
– CO2 absorbs primarily “infrared” light
3-Channel Spectrometer (JPL/HS) Dedicated Dedicated Spacecraft Taurus XL bus (OSC) 3110 (KSC) Mission Ops (OSC) NASA GN (GSFC) and SN (TDRSS) Formation Flying as part of the A-Train Constellation
The NASA Orbiting Carbon Observatory: Measuring Carbon Dioxide from Space

David Crisp (JPL/Caltech) OCO Principal Investigator February 2009
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Global Fossil Fuel Emission Forecasts
10 Carbon Emissions (GtC/y) 9 8 7 6 5 1990
Actual emissions: CDIAC Actual emissions: EIA 2006 Emissions: 8.4 Gt ! 450ppm stabilisation 650ppm stabilisation 2006 A1FI 2005 A1B A1T A2 B1 B2
Initial Surf/Atm State Generate Synthetic Spectrum Instrument Model Difference Spectra Inverse Model
• Validate measurements to ensure XCO2 accuracy of 1 - 2 ppm (0.3 - 0.5%)
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CO2 Measurements
CO2 Ground Network
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Carbon Dioxide and Climate
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Greenhouse Effects
OCO Data Center Validation Program
Ground Data Processing Center (JPL) L2 XCO2 Retrieval Calibration Program
Full Physics Validation Model
Please visit for more information
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By resolving the colors of reflected sunlight in near IR CO2 and O2 bands, we can measure the absorption by each molecule – 2.06 μm CO2 band: Column CO2, Aerosols – 1.61 μm CO2 band: Column CO2 – 0.76 μm O2 A-band: Surface pressure, clouds, aerosols
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On Thin Ice
1979 From the Climate Time Machine@ / 2007
/vis/a000000/a003400/a003464/index.html
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A gallon of diesel weighs ~6.7 lbs (3.04 kg),
– Diesel is 87% carbon, so 0.87*6.7 lbs = 5.83 lbs (2.65 kg or 0.22 kmole @ 12 kg/kmole) – When burned, this 2.65 kg of carbon combines with 0.22 kmole of O2 (0.22*32 kg/kmole=7.1 kg) to yield 9.75 kg or 21.5 lbs of CO2
– Land or ocean? – Eurasia/North America?
• Why does the CO2 buildup vary from year to year with nearly uniform emission rates? • How will these CO2 sinks respond to climate change?
O2 A-band CO2 2.06 μm
CO2 1.61μm
Clouds/Aerosols, Surface Pressure
Column CO2
CO2, Aerosols, H2O, Temperature
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Mission System Description
1995
2000
2005
2010
Raupach et al., PNAS, 2007.
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CO2 Released by Fossil Fuels
• A gallon of gasoline weighs ~6.3 lbs (2.86 kg)
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OCO/AIRS/GOSAT
New State (inc. XCO2)
FTS Tower Aircraft
XCO2
Flask
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Precise Measurements are Needed to Resolve XCO2 Variations 380
– The average European produces ~14 tons CO2/year – The average Japanese produces ~9.6 tons CO2/year – The average Chinese produces ~2 tons CO2/year
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– Gasoline is 87% Carbon, so 0.87*6.3 lbs=5.48 lbs (2.5 kg, or 0.2 kmole @12 kg/kmole) – When burned, this 2.5 kg of carbon combines with 0.2 kmole of O2 (0.2*32 kg/kmole=6.4 kg) to yield 8.9 kg or 19.6 lbs of CO2 ~20 lbs (8.9 kg) CO2
Carbon Dioxide (CO2) can trap thermal radiation (heat) that the Earth would otherwise emit to space. The use of fossil fuels (coal, oil, natural gas) and other human activities are rapidly increasing the amount of CO2 in the atmosphere raising concerns about global warming
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CO2 and the Global Carbon Cycle
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9 GtC/yr
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Outstanding Questions
• Humans have added >200 Gt C to the atmosphere since 1958 • Only about half of this CO2 is staying in the atmosphere • Where are the sinks that are absorbing half of the CO2?
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Measurement Approach
• Collect spectra of CO2 & O2 absorption in reflected sunlight over the globe • Retrieve variations in the column averaged CO2 dry air mole fraction, XCO2 over sunlit hemisphere
l 1 Ga G AS
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Similarly, a gallon of Jet Fuel (Kerosene) produces 21.1 lbs (9.59 kg) of CO2
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Your Carbon Footprint