We compare AIRS, IASI-A and CrIS under the cold conditions encountered in the daily overpasses of Dome Concordia, located on a high plateau in Antarctica, between May 2012 and March 2016. The mean brightness temperature at DomeC for the 900 cm-1 atmospheric window channel is 218K, but it varies seasonally from 185K to 255K. Averaged over all simultaneous overpass data AIRS is 26±13 mK warmer than IASI-A, AIRS is 116±7 mK colder than CrIS. This is excellent agreement and consistent with SNO analysis in the literature. However, we find that differences for both AIRS/IASI-A and AIRS/CrIS are temperature dependent. AIRS is 120 mK colder at 200K, but 150 mK warmer at 230K than IASI-A. AIRS is 120 mK colder at 200K, 50mK colder at 230K than CrIS. Differences and scene temperature sensitivity of this magnitude have also been reported by other investigators. A scene temperature dependence bias can create a sampling bias which need to be taken into account when comparing data from current instruments, and even more so when analyzing data from vintage instruments with respect to climate change.
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