...

Two reanalyses cover the the period 20070101 to 20151231. They have been run using the ERA5 reanalysis system, but at low resolution (T159), 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. 

The two reanalyses provide:

...

This reanalysis data is available for the surface, on 37 fixed pressure levels and 137 model levels.

Access

...

to the ROM SAF data using web-api

The ROM SAF datasets can be retrieved using the ECMWF web-api service. The ECMWF web-api is a "programmatic approach" for data download using python scripts, and frequently asked . Frequently asked web-api questions (FAQs) can be found here.

...

The importance retrieval efficiency when using web-api is discussed here. This page includes web-api retrieval examples for other reanalyses, such as ERA5. 

...