MIPAS NOM, MA, and UA measurements help to validate new SMR H2O v3.0 data set

Comparison of version 3.0 SMR H₂O profiles with MIPAS V5 upper atmosphere mode retrievals. The data plotted are based on global averages. Left panel shows volume mixing ratios, centre panel shows absolute differences, and right panel shows relative differences (as percentage). Differences are calculated as medians of single profile differences. Dashed lines represent the standard deviation of the median.

The new version 3.0 data set of mesospheric H₂O from the Sub-Millimetre Radiometer (SMR) aboard the Odin satellite has been validated against H₂O data of various other satellite instruments. Among these, MIPAS version 5 nominal, middle atmosphere, and upper atmosphere measurements have been used. The latter two are of special interest since the new SMR H₂O data product extends between 40 and 100 km altitude and explicitely aims at the conditions in the mesosphere. The validation study has revealed an overall better accordance with the comparison instruments for the new SMR version 3.0 H₂O profiles, compared to earlier SMR data versions.

The publication describing the details of the SMR retrieval and validation is https://doi.org/10.5194/amt-14-5823-2021
The MIPAS V5 H₂O data is available from https://www.imk-asf.kit.edu/english/308.php