There's climate reanalysis, which combines historical observations with weather models to get clean data of past weather conditions, which is then used by resea

There's climate reanalysis, which combines historical observations with weather models to get clean data of past weather conditions, which is then used by researchers for various purposes. Most notably is ERA5 by ECMWF. [0] https://en.wikipedia.org/wiki/ECMWF_re-analysis https://en.wikipedia.org/wiki/ECMWF_re-analysis