ECMWF has announced that the Copernicus Climate Change Service (C3S) has begun the release of the ERA5 back extension data covering the period 1950-1978 on the Climate Data Store (CDS).
Although in many other respects the quality of this dataset is quite satisfactory, the current back extension appears to suffer from tropical cyclones that are sometimes unrealistically intense. This is in contrast with the ERA5 product from 1979 onwards (also available from the CDS and RDA-ds633.0). For more details see the article, ERA5 back extension 1950-1978 (Preliminary version): tropical cyclones are too intense.
For this reason the current release of the back extension is preliminary.
It is therefore available from separate CDS catalogue entries (hourly, monthly, single level and pressure levels), and RDA dataset ds633.4 ERA5 back extension 1950-1978 (Preliminary version). Around the end of 2021 an updated version of the back extension is to be made available which will be added to the ERA5 catalogue entries that currently reach back to 1979. After an overlap period (the duration of which is not yet decided), the preliminary back extension will be deprecated.
The full back extension preliminary dataset is expected to be made available near the end of 2020/early 2021.
