Carbon dioxide global measurements
Monitoring carbon dioxide (CO2) fluxes provides a better insight into the changes in the global carbon cycle related to natural sources and human-made emissions. Until recently atmospheric CO2 concentrations were mainly monitored through sparse earth-based observation systems, for example oceanic stations. Unfortunately there are approximately a hundred stations that gather data on a regular basis. Moreover, very few of them are adequately tall enough to cover vertical CO2 profiles with increased accuracy. Advancements in satellite infrastructure offered space borne measurements of CO2 concentrations that can complement observations from earth-based monitoring systems. Moving one step ahead the COCO project focused on exploiting space missions for retrieving detailed estimations of CO2 column integrals. Using new methodologies, the project's research work aimed at employing satellite data for the estimation of CO2 vertical column abundances in the atmosphere. With the aid of suitable models of atmospheric transport, these estimations can further be employed for the calculation of surface fluxes. Project research work took advantage of the spectral characteristics of existing systems that measure the atmospheric infrared radiation for retrieving CO2 column integrals. Such systems included the Atmospheric Infrared Sounder (AIRS) and the TIROS (Television Infrared Observation Satellite) Operational Vertical Sounder (TOVS). The Max-Planck Institute for Biogeochemistry conducted detailed comparisons of the retrieved CO2 column integrals against those gathered from in situ aircraft measurements and model simulations. It was shown that the upper troposphere CO2 concentration patterns revealed by both systems were in good accordance with those derived from model simulations and in situ aircraft measurements. Particularly, the AIRS retrievals were in better agreement with earth borne data than the TOVS ones. For further information on the project click at the project site: http://www.bgc-jena.mpg.de/bgc-systems/projects/Coco/
