Spaceborne detection of localized carbon dioxide sources

Area of Science:

• Atmospheric Science
• Remote Sensing
• Geochemistry

Background:

• Atmospheric carbon dioxide (CO2) concentrations are influenced by both natural and anthropogenic sources.
• Accurate measurement of localized CO2 emissions is crucial for understanding global carbon cycles.
• Previous satellite capabilities had limitations in resolving fine-scale CO2 distribution from point sources.

Purpose of the Study:

• To demonstrate the capability of NASA's Orbiting Carbon Observatory-2 (OCO-2) to detect and characterize localized atmospheric CO2 enhancements.
• To differentiate CO2 plumes originating from urban anthropogenic activities and natural geological sources.
• To assess the spatial extent and concentration of CO2 plumes from distinct point sources.

Main Methods:

• Utilized spaceborne measurements from the OCO-2 satellite, achieving kilometer-scale resolution.
• Analyzed OCO-2 transects across the Los Angeles megacity to map urban CO2 enhancements.
• Examined OCO-2 data from a transect downwind of the Yasur volcano to identify a natural CO2 plume.

Main Results:

• OCO-2 detected distinct CO2 enhancements peaking over the Los Angeles urban core, diminishing over ~100 km.
• Seasonal CO2 variations in the Los Angeles area ranged from approximately 4.4 to 6.1 parts per million.
• A narrow CO2 plume was identified downwind of Yasur volcano, consistent with an emission rate of 41.6 kilotons per day.

Conclusions:

• OCO-2's high resolution and sensitivity enable the detection of localized anthropogenic and natural CO2 sources.
• The findings highlight OCO-2's potential for detailed monitoring of CO2 emissions at regional and local scales.
• This capability is vital for improving carbon emission inventories and understanding regional carbon budgets.