ModE-RA is a monthly 3-dimensional reanalysis product covering the period from 1421 to 2008. It was created by combining information on historical climate - including early instrumental data, documentary data, and proxy data - with additional physical constraints from ModE-Sim (Modern Era Simulations, to be found within this WDC project as a separate experiment), a large ensemble of simulations with an atmospheric general circulation model. Observed anomalies were assimilated with an offline Ensemble Kalman filtering technique.
In addition to ModE-RA, which uses 20 distinct transient members of ModE-Sim, this WDC project includes ModE-RAclim, an alternative version of the reanalysis product. Instead of 20 distinct transient members of the AGCM ensemble, ModE-RAclim uses 100 randomly picked years from ModE-Sim as a priori state for improved covariance estimation, but introducing covariance stationarity and eliminating the externally forced signal in the model simulations.
Reference for ModE-RA and ModE-RAclim:
Veronika Valler, Franke. J. , Brugnara. Y. , Samakinwa, E., Hand, R. , Lundstad, E., Burgdorf, A., and Stefan Brönnimann, 2023 (in preparation): ModE-RA - A global monthly paleo-reanalysis of the modern era (1421 to 2008), to be submitted to Nature scientific data.