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How do we measure the average concentration of CO2 in the atmosphere, given all the disparity and local extremums?
by tajen 10y ago
How do we measure the average concentration of CO2 in the atmosphere, given all the disparity and local extremums?
- wollstonecraft 10y agoThis article cites a measurement from Mauna Loa Observatory.
- mturmon 10y agoThe article describes an in situ (ground based) measurement, that is sample based. You can get CO2 concentrations from satellite remote sensing, as well. Usually they use spectral analysis of CO2 emission/absorption lines in the infrared. This is a passive measurement, but active measurements with lasers are used in ground based and airborne measurements now. These measurements are of CO2 within a given (vertical) column of air -- where the infrared light came from -- whereas the Mauna Loa measurement in TFA is localized to air moving past the sample station. One starting place for CO2 data is: https://co2.jpl.nasa.gov https://co2.jpl.nasa.gov This summary of Los Angeles area ground based measurements hints at some of the complexities of integrating these different data sources: https://megacities.jpl.nasa.gov/portal/collection-network/ https://megacities.jpl.nasa.gov/portal/collection-network/ . Other pages on that site indicate the extreme spatial and temporal variability of CO2 in an urban setting. That's why the comparatively pristine Mauna Loa site is so important.
- shouldbworking 10y agoSatellite I believe. CO2 absorbs certain bands in the infrared range. You can probably use optical spectrometry to measure relative concentration.