Comparison of SCIAMACHY and AIRS CO ₂ measurements over China from 2003 to 2005

Increased CO ₂ (carbon dioxide) has been considered as one of key factors of global warming. Intending to describe the capability of CO ₂ measurement by space-borne sensors quantitatively, this paper compares two data sets of CO ₂ monthly products retrieved from AIRS and SCIAMACHY over China from 2003 to 2005. The increasing trend of CO ₂ concentration can be detected consistently from both of the data sets. However, the seasonal variation of AIRS CO ₂ is larger than SCIAMACHY CO ₂ because the former represents CO ₂ existing in the mid-troposphere while the latter represents in the lower-troposphere. CO ₂ concentration reaches its yearly maximum in spring (April and May) and reaches its yearly minimum in late-autumn and winter (October to December and January) for both data sets. The coverage of AIRS monthly CO ₂ is much better than that of SCIAMACHY over China and it shows that Xinjiang, Tibet, Inner Mongolia and northeast China have higher values than other regions in China especially in April and May due to local climate and vegetation growth process.