To date, the measurements from AIRS, GOSAT, SCIAMACHY and IASI are widely used to derive atmospheric CO₂ concentration globally. Quantification of the spatio-temporal differences between these CO₂ products is crucial for deeply understanding each product and for exploring the potential for their joint use in the future. A series of processing has been proposed in this paper to unify these existing CO₂ products, so that they can be theoretically comparable. Based on this, the spatio-temporal variations of these CO₂ products have been conducted. The results reveal that AIRS show the largest spatial coverage of CO₂ compared to other CO₂ products. The valid X_CO2 data from SCIAMACHY are mainly restricted to land regions. Even if over the land, the X_CO2 distribution of ACOS is slightly wider than that of SCIAMACHY, especially over the region of Eurasia and North America. An obvious arch-shaped pattern along latitude for ACOS, Japan-GOSAT and SCIAMACHY is detected, while no distinct latitudinal variation can be observed for AIRS. For the seasonal variation, these datasets show a similar trend with the maximum CO₂ loading occurring in spring. The discrepancy between these products implies that it is greatly necessary to better constrain the uncertainties in CO₂ retrieval from space in the future.

Date Published: 5 December 2012
PDF: 8 pages
Proc. SPIE 8562, Infrared, Millimeter-Wave, and Terahertz Technologies II, 85620J (5 December 2012); doi: 10.1117/12.2001088

Published in SPIE Proceedings Vol. 8562:
Infrared, Millimeter-Wave, and Terahertz Technologies II
Cunlin Zhang; Xi-Cheng Zhang; He Li; Sheng-Cai Shi, Editor(s)