As a precursor to a revised extended reanalysis product to replace ERA-40, ECMWF released ERA-Interim, which covers the period from 1979 to 2019.
A new reanalysis product ERA5 has more recently been released by ECMWF as part of Copernicus Climate Change Services.
Many sources of the meteorological observations were used, including radiosondes, balloons, aircraft, buoyes, satellites, scatterometers.
[2] As the ECMWF's computer model is one of the more highly regarded in the field of forecasting, many scientists take its reanalysis to have similar merit.
A Python web API can be used to download a subset of parameters for a selected region and time period.