The Greenhouse gases Observing SATellite "IBUKI", developed jointly by the Ministry of the Environment (MOE), the National Institute for Environmental Studies (NIES), and the Japan Aerospace Exploration Agency (JAXA) is the world's only satellite designed specifically to monitor greenhouse gases from space. The satellite has continued to fulfill its main mission in monitoring atmospheric carbon dioxide (CO2) and methane concentrations from space to improve the accuracy of sink/source estimates, and achieve its target to contribute to precision refinement for the ongoing elucidation of carbon cycles, since its launch on January 23, 2009.
CO2 concentrations in mega-cities and their surroundings were analyzed for the three and half years from June 2009 to December 2012, based on the observational data acquired by "IBUKI", indicating the tendency for higher CO2 concentrations in mega-cities than those in their surroundings. Furthermore, positive correlations were shown between differences in CO2 concentrations and the concentrations estimated from data for fossil fuel consumption. These results indicate that "IBUKI" observations have the potential to enable us to detect enhanced CO2 concentrations with their origin in fossil fuel consumption for mega-cities. These studies demonstrate the potential utility of satellite observation of CO2 concentrations as a tool for monitoring greenhouse gas emissions (inventory) from fossil fuels.
With the progress in studies to monitor large point CO2 sources by satellite observation and other methods, these results will be applied to current and forthcoming research projects involving "IBUKI" and its successor - GOSAT-2 - to be launched in 2018.