Interannual variability of mid‐tropospheric CO₂ from Atmospheric Infrared Sounder

Abstract

Atmospheric Infrared Sounder (AIRS) offers a unique opportunity to investigate the variability of mid‐tropospheric CO 2 over the entire globe. In this paper, we use AIRS data to examine the interannual variability of CO 2 and find significant correlations between AIRS mid‐tropospheric CO 2 and large‐scale atmospheric dynamics. During El Niño events, mid‐tropospheric CO 2 over the central Pacific Ocean is enhanced whereas it is reduced over the western Pacific Ocean as a result of the change in the Walker circulation. The variation of AIRS CO 2 in the high latitudes of the northern hemisphere is closely related to the strength of the northern hemispheric annular mode. These results contribute to a better understanding of the influence of large‐scale dynamics on tracer distributions.