...
The two atmopsheric reanalyses cover the the period 20070101 to 20151231. They have been run using the ERA5 reanalysis system, but at low resolution (T159 ~ 125 km grid), and using a static B matrix rather than ERA5's flow-dependent version which uses the Ensemble of Data Assimilations approach. The first ROM SAF reanalysis assimilates just reprocessed GPS-RO data provided the ROM SAF and AMSUA channel 14 to constrain the upper stratosphere. The second reanalysis also includes conventional measurements (e.g., sondes, synop, ...) that are not bias corrected as part of the variational bias correction (VAR-BC) scheme. Notably, this excludes aircraft temperature measurements that are bias corrected in VAR-BC.
...