Comparison analysis of global methane concentration derived from SCIAMACHY, AIRS, and GOSAT with surface station measurements

CH4 (methane) is an important greenhouse gas that has a significant impact on the formation of, and change in, the global climate. Through the development of remote sensing technology, a series of remote sensing detectors to monitor CH4 sources and sinks have been launched into space. Although a series of studies have been conducted around the CH4 concentration retrieved by AIRS (The Atmospheric Infrared Sounder instrument), SCIAMACHY (The Scanning Imaging Absorption spectrometer for Atmospheric Chartography instrument), and GOSAT (The Greenhouse Gases Observing Satellite), there have been few comprehensive comparative studies between these three satellite results and ground-based data. In this article, the correlation coefficient, root-mean-square deviation (RMSD), and bias are used to evaluate the CH4 retrieved from satellite data. The results reveal that: AIRS can reflect the distribution and changes of CH4 all over the world. The space coverage of GOSAT is focused between 60°S to 60°N, and the correlation of GOSAT with land surface stations is generally better than that with ocean surface stations. The space coverage of SCIAMACHY is between GOSAT and AIRS. Though SCIAMACHY data show a poor consistency with surface measurements, SCIAMACHY can also reflect the spatial and temporal dynamic distribution of CH4 around the world to a certain extent.